WorldWideScience

Sample records for flight test vibration

  1. Force Limiting Vibration Tests Evaluated from both Ground Acoustic Tests and FEM Simulations of a Flight Like Vehicle System Assembly

    Science.gov (United States)

    Smith, Andrew; LaVerde, Bruce; Waldon, James; Hunt, Ron

    2014-01-01

    Marshall Space Flight Center has conducted a series of ground acoustic tests with the dual goals of informing analytical judgment, and validating analytical methods when estimating vibroacoustic responses of launch vehicle subsystems. The process of repeatedly correlating finite element-simulated responses with test-measured responses has assisted in the development of best practices for modeling and post-processing. In recent work, force transducers were integrated to measure interface forces at the base of avionics box equipment. Other force data was indirectly measured using strain gauges. The combination of these direct and indirect force measurements has been used to support and illustrate the advantages of implementing the Force Limiting approach for equipment qualification tests. The comparison of force response from integrated system level tests to measurements at the same locations during component level vibration tests provides an excellent illustration. A second comparison of the measured response cases from the system level acoustic tests to finite element simulations has also produced some principles for assessing the suitability of Finite Element Models (FEMs) for making vibroacoustics estimates. The results indicate that when FEM models are employed to guide force limiting choices, they should include sufficient detail to represent the apparent mass of the system in the frequency range of interest.

  2. Hot Ground Vibration Tests

    Data.gov (United States)

    National Aeronautics and Space Administration — Ground vibration tests or modal surveys are routinely conducted to support flutter analysis for subsonic and supersonic vehicles. However, vibration testing...

  3. Coupled thermal, structural and vibrational analysis of a hypersonic engine for flight test

    Energy Technology Data Exchange (ETDEWEB)

    Sook-Ying, Ho [Defence Science and Technology Organisation, SA (Australia); Paull, A. [Queensland Univ., Dept. of Mechanical Engineering (Australia)

    2006-07-15

    This paper describes a relatively simple and quick method for implementing aerodynamic heating models into a finite element code for non-linear transient thermal-structural and thermal-structural-vibrational analyses of a Mach 10 generic HyShot scram-jet engine. The thermal-structural-vibrational response of the engine was studied for the descent trajectory from 60 to 26 km. Aerodynamic heating fluxes, as a function of spatial position and time for varying trajectory points, were implemented in the transient heat analysis. Additionally, the combined effect of varying dynamic pressure and thermal loads with altitude was considered. This aero-thermal-structural analysis capability was used to assess the temperature distribution, engine geometry distortion and yielding of the structural material due to aerodynamic heating during the descent trajectory, and for optimising the wall thickness, nose radius of leading edge, etc. of the engine intake. A structural vibration analysis was also performed following the aero-thermal-structural analysis to determine the changes in natural frequencies of the structural vibration modes that occur at the various temperatures associated with the descent trajectory. This analysis provides a unique and relatively simple design strategy for predicting and mitigating the thermal-structural-vibrational response of hypersonic engines. (authors)

  4. Multi-Exciter Vibroacoustic Simulation of Hypersonic Flight Vibration

    International Nuclear Information System (INIS)

    GREGORY, DANNY LYNN; CAP, JEROME S.; TOGAMI, THOMAS C.; NUSSER, MICHAEL A.; HOLLINGSHEAD, JAMES RONALD

    1999-01-01

    Many aerospace structures must survive severe high frequency, hypersonic, random vibration during their flights. The random vibrations are generated by the turbulent boundary layer developed along the exterior of the structures during flight. These environments have not been simulated very well in the past using a fixed-based, single exciter input with an upper frequency range of 2 kHz. This study investigates the possibility of using acoustic ardor independently controlled multiple exciters to more accurately simulate hypersonic flight vibration. The test configuration, equipment, and methodology are described. Comparisons with actual flight measurements and previous single exciter simulations are also presented

  5. Benefits of Spacecraft Level Vibration Testing

    Science.gov (United States)

    Gordon, Scott; Kern, Dennis L.

    2015-01-01

    NASA-HDBK-7008 Spacecraft Level Dynamic Environments Testing discusses the approaches, benefits, dangers, and recommended practices for spacecraft level dynamic environments testing, including vibration testing. This paper discusses in additional detail the benefits and actual experiences of vibration testing spacecraft for NASA Goddard Space Flight Center (GSFC) and Jet Propulsion Laboratory (JPL) flight projects. JPL and GSFC have both similarities and differences in their spacecraft level vibration test approach: JPL uses a random vibration input and a frequency range usually starting at 5 Hz and extending to as high as 250 Hz. GSFC uses a sine sweep vibration input and a frequency range usually starting at 5 Hz and extending only to the limits of the coupled loads analysis (typically 50 to 60 Hz). However, both JPL and GSFC use force limiting to realistically notch spacecraft resonances and response (acceleration) limiting as necessary to protect spacecraft structure and hardware from exceeding design strength capabilities. Despite GSFC and JPL differences in spacecraft level vibration test approaches, both have uncovered a significant number of spacecraft design and workmanship anomalies in vibration tests. This paper will give an overview of JPL and GSFC spacecraft vibration testing approaches and provide a detailed description of spacecraft anomalies revealed.

  6. Ground test for vibration control demonstrator

    Science.gov (United States)

    Meyer, C.; Prodigue, J.; Broux, G.; Cantinaud, O.; Poussot-Vassal, C.

    2016-09-01

    In the objective of maximizing comfort in Falcon jets, Dassault Aviation is developing an innovative vibration control technology. Vibrations of the structure are measured at several locations and sent to a dedicated high performance vibration control computer. Control laws are implemented in this computer to analyse the vibrations in real time, and then elaborate orders sent to the existing control surfaces to counteract vibrations. After detailing the technology principles, this paper focuses on the vibration control ground demonstration that was performed by Dassault Aviation in May 2015 on Falcon 7X business jet. The goal of this test was to attenuate vibrations resulting from fixed forced excitation delivered by shakers. The ground test demonstrated the capability to implement an efficient closed-loop vibration control with a significant vibration level reduction and validated the vibration control law design methodology. This successful ground test was a prerequisite before the flight test demonstration that is now being prepared. This study has been partly supported by the JTI CleanSky SFWA-ITD.

  7. Microgravity Active Vibration Isolation System on Parabolic Flights

    Science.gov (United States)

    Dong, Wenbo; Pletser, Vladimir; Yang, Yang

    2016-07-01

    The Microgravity Active Vibration Isolation System (MAIS) aims at reducing on-orbit vibrations, providing a better controlled lower gravity environment for microgravity physical science experiments. The MAIS will be launched on Tianzhou-1, the first cargo ship of the China Manned Space Program. The principle of the MAIS is to suspend with electro-magnetic actuators a scientific payload, isolating it from the vibrating stator. The MAIS's vibration isolation capability is frequency-dependent and a decrease of vibration of about 40dB can be attained. The MAIS can accommodate 20kg of scientific payload or sample unit, and provide 30W of power and 1Mbps of data transmission. The MAIS is developed to support microgravity scientific experiments on manned platforms in low earth orbit, in order to meet the scientific requirements for fluid physics, materials science, and fundamental physics investigations, which usually need a very quiet environment, increasing their chances of success and their scientific outcomes. The results of scientific experiments and technology tests obtained with the MAIS will be used to improve future space based research. As the suspension force acting on the payload is very small, the MAIS can only be operative and tested in a weightless environment. The 'Deutsches Zentrum für Luft- und Raumfahrt e.V.' (DLR, German Aerospace Centre) granted a flight opportunity to the MAIS experiment to be tested during its 27th parabolic flight campaign of September 2015 performed on the A310 ZERO-G aircraft managed by the French company Novespace, a subsidiary of the 'Centre National d'Etudes Spatiales' (CNES, French Space Agency). The experiment results confirmed that the 6 degrees of freedom motion control technique was effective, and that the vibration isolation performance fulfilled perfectly the expectations based on theoretical analyses and simulations. This paper will present the design of the MAIS and the experiment results obtained during the

  8. Flight research and testing

    Science.gov (United States)

    Putnam, Terrill W.; Ayers, Theodore G.

    1989-01-01

    Flight research and testing form a critical link in the aeronautic research and development chain. Brilliant concepts, elegant theories, and even sophisticated ground tests of flight vehicles are not sufficient to prove beyond a doubt that an unproven aeronautical concept will actually perform as predicted. Flight research and testing provide the ultimate proof that an idea or concept performs as expected. Ever since the Wright brothers, flight research and testing were the crucible in which aeronautical concepts were advanced and proven to the point that engineers and companies are willing to stake their future to produce and design aircraft. This is still true today, as shown by the development of the experimental X-30 aerospace plane. The Dryden Flight Research Center (Ames-Dryden) continues to be involved in a number of flight research programs that require understanding and characterization of the total airplane in all the aeronautical disciplines, for example the X-29. Other programs such as the F-14 variable-sweep transition flight experiment have focused on a single concept or discipline. Ames-Dryden also continues to conduct flight and ground based experiments to improve and expand the ability to test and evaluate advanced aeronautical concepts. A review of significant aeronautical flight research programs and experiments is presented to illustrate both the progress being made and the challenges to come.

  9. Force Limited Vibration Test of HESSI Imager

    Science.gov (United States)

    Amato, Deborah; Pankow, David; Thomsen, Knud

    2000-01-01

    The High Energy Solar Spectroscopic Imager (HESSI) is a solar x-ray and gamma-ray observatory scheduled for launch in November 2000. Vibration testing of the HESSI imager flight unit was performed in August 1999. The HESSI imager consists of a composite metering tube, two aluminum trays mounted to the tube on titanium flexure mounts, and nine modulation grids mounted on each tray. The vibration tests were acceleration controlled and force limited, in order to prevent overtesting. The force limited strategy reduced the shaker force and notched the acceleration at resonances. The test set-up, test levels, and results are presented. The development of the force limits is also discussed. The imager successfully survived the vibration testing.

  10. ALOFT Flight Test Report

    Science.gov (United States)

    1977-10-01

    wmmmmmmmmmmmm i ifmu.immM\\]i\\ ßinimm^mmmmviwmmiwui »vimtm twfjmmmmmmi c-f—rmSmn NWC TP 5954 ALOFT Flight Test Report by James D. Ross anrJ I.. M...responsible i"- u conducting the ALOFT Flight Test Program and made contributions to this report: J. Basden , R. ".estbrook, L. Thompson, J. Willians...REPORT DOCUMENTATION PAGE READ INSTRUCTIONS BEFORE COMPLETING FORM 7. AUTMORC«; <oss James D./Xo L. M.y&ohnson IZATION NAME AND ADDRESS Naval

  11. Weather and Flight Testing

    Science.gov (United States)

    Wiley, Scott

    2007-01-01

    This viewgraph document reviews some of the weather hazards involved with flight testing. Some of the hazards reviewed are: turbulence, icing, thunderstorms and winds and windshear. Maps, pictures, satellite pictures of the meteorological phenomena and graphs are included. Also included are pictures of damaged aircraft.

  12. Performance of active vibration control technology: the ACTEX flight experiments

    Science.gov (United States)

    Nye, T. W.; Manning, R. A.; Qassim, K.

    1999-12-01

    This paper discusses the development and results of two intelligent structures space-flight experiments, each of which could affect architecture designs of future spacecraft. The first, the advanced controls technology experiment I (ACTEX I), is a variable stiffness tripod structure riding as a secondary payload on a classified spacecraft. It has been operating well past its expected life since becoming operational in 1996. Over 60 on-orbit experiments have been run on the ACTEX I flight experiment. These experiments form the basis for in-space controller design problems and for concluding lifetime/reliability data on the active control components. Transfer functions taken during the life of ACTEX I have shown consistent predictability and stability in structural behavior, including consistency with those measurements taken on the ground prior to a three year storage period and the launch event. ACTEX I can change its modal characteristics by employing its dynamic change mechanism that varies preloads in portions of its structure. Active control experiments have demonstrated maximum vibration reductions of 29 dB and 16 dB in the first two variable modes of the system, while operating over a remarkable on-orbit temperature range of -80 °C to 129 °C. The second experiment, ACTEX II, was successfully designed, ground-tested, and integrated on an experimental Department of Defense satellite prior to its loss during a launch vehicle failure in 1995. ACTEX II also had variable modal behavior by virtue of a two-axis gimbal and added challenges of structural flexibility by being a large deployable appendage. Although the loss of ACTEX II did not provide space environment experience, ground testing resulted in space qualifying the hardware and demonstrated 21 dB, 14 dB, and 8 dB reductions in amplitude of the first three primary structural modes. ACTEX II could use either active and/or passive techniques to affect vibration suppression. Both experiments trailblazed

  13. AVM branch vibration test equipment

    International Nuclear Information System (INIS)

    Anne, J.P.

    1995-01-01

    An inventory of the test equipment of the AVM Branch ''Acoustic and Vibratory Mechanics Analysis Methods'' group has been undertaken. The purpose of this inventory is to enable better acquaintance with the technical characteristics of the equipment, providing an accurate definition of their functionalities, ad to inform potential users of the possibilities and equipment available in this field. The report first summarizes the various experimental surveys conduced. Then, using the AVM equipment database to draw up an exhaustive list of available equipment, it provides a full-scope picture of the vibration measurement systems (sensors, conditioners and exciters) and data processing resources commonly used on industrial sites and in laboratories. A definition is also given of a mobile test unit, called 'shelter', and a test bench used for the testing and performance rating of the experimental analysis methods developed by the group. The report concludes with a description of two fixed installations: - the calibration bench ensuring the requisite quality level for the vibration measurement systems ; - the training bench, whereby know-how acquired in the field in the field of measurement and experimental analysis processes is made available to others. (author). 27 refs., 15 figs., 2 appends

  14. Inficon Transpector MPH Mass Spectrometer Random Vibration Test Report

    Science.gov (United States)

    Santiago-Bond, Jo; Captain, Janine

    2015-01-01

    The purpose of this test report is to summarize results from the vibration testing of the INFICON Transpector MPH100M model Mass Spectrometer. It also identifies requirements satisfied, and procedures used in the test. As a payload of Resource Prospector, it is necessary to determine the survivability of the mass spectrometer to proto-qualification level random vibration. Changes in sensitivity of the mass spectrometer can be interpreted as a change in alignment of the instrument. The results of this test will be used to determine any necessary design changes as the team moves forward with flight design.

  15. Aviation Flight Test

    Data.gov (United States)

    Federal Laboratory Consortium — Redstone Test Center provides an expert workforce and technologically advanced test equipment to conduct the rigorous testing necessary for U.S. Army acquisition and...

  16. Integrated Test and Evaluation Flight Test 3 Flight Test Plan

    Science.gov (United States)

    Marston, Michael Lawrence

    2015-01-01

    The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration into the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability, Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including the integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project will conduct a series of Human-in-the-Loop and Flight Test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity and complexity of the previous tests and

  17. 14 CFR 33.43 - Vibration test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vibration test. 33.43 Section 33.43... STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.43 Vibration test. (a) Each... configuration of the propeller type which is used for the endurance test, and using, for other engines, the same...

  18. 14 CFR 33.83 - Vibration test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vibration test. 33.83 Section 33.83... STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.83 Vibration test. (a) Each engine... experience, analysis, and component test and shall address, as a minimum, blades, vanes, rotor discs, spacers...

  19. Verification of the Microgravity Active Vibration Isolation System based on Parabolic Flight

    Science.gov (United States)

    Zhang, Yong-kang; Dong, Wen-bo; Liu, Wei; Li, Zong-feng; Lv, Shi-meng; Sang, Xiao-ru; Yang, Yang

    2017-12-01

    The Microgravity active vibration isolation system (MAIS) is a device to reduce on-orbit vibration and to provide a lower gravity level for certain scientific experiments. MAIS system is made up of a stator and a floater, the stator is fixed on the spacecraft, and the floater is suspended by electromagnetic force so as to reduce the vibration from the stator. The system has 3 position sensors, 3 accelerometers, 8 Lorentz actuators, signal processing circuits and a central controller embedded in the operating software and control algorithms. For the experiments on parabolic flights, a laptop is added to MAIS for monitoring and operation, and a power module is for electric power converting. The principle of MAIS is as follows: the system samples the vibration acceleration of the floater from accelerometers, measures the displacement between stator and floater from position sensitive detectors, and computes Lorentz force current for each actuator so as to eliminate the vibration of the scientific payload, and meanwhile to avoid crashing between the stator and the floater. This is a motion control technic in 6 degrees of freedom (6-DOF) and its function could only be verified in a microgravity environment. Thanks for DLR and Novespace, we get a chance to take the DLR 27th parabolic flight campaign to make experiments to verify the 6-DOF control technic. The experiment results validate that the 6-DOF motion control technique is effective, and vibration isolation performance perfectly matches what we expected based on theoretical analysis and simulation. The MAIS has been planned on Chinese manned spacecraft for many microgravity scientific experiments, and the verification on parabolic flights is very important for its following mission. Additionally, we also test some additional function by microgravity electromagnetic suspension, such as automatic catching and locking and working in fault mode. The parabolic flight produces much useful data for these experiments.

  20. Supersonic Retropropulsion Flight Test Concepts

    Science.gov (United States)

    Post, Ethan A.; Dupzyk, Ian C.; Korzun, Ashley M.; Dyakonov, Artem A.; Tanimoto, Rebekah L.; Edquist, Karl T.

    2011-01-01

    NASA's Exploration Technology Development and Demonstration Program has proposed plans for a series of three sub-scale flight tests at Earth for supersonic retropropulsion, a candidate decelerator technology for future, high-mass Mars missions. The first flight test in this series is intended to be a proof-of-concept test, demonstrating successful initiation and operation of supersonic retropropulsion at conditions that replicate the relevant physics of the aerodynamic-propulsive interactions expected in flight. Five sub-scale flight test article concepts, each designed for launch on sounding rockets, have been developed in consideration of this proof-of-concept flight test. Commercial, off-the-shelf components are utilized as much as possible in each concept. The design merits of the concepts are compared along with their predicted performance for a baseline trajectory. The results of a packaging study and performance-based trade studies indicate that a sounding rocket is a viable launch platform for this proof-of-concept test of supersonic retropropulsion.

  1. Fueled viking generator S/N 106 acceptance vibration test report

    International Nuclear Information System (INIS)

    Anderson, C.; Brewer, C.O.; Abrahamson, S.G.

    1976-01-01

    The Viking Generator S/N 106 was vibrated to the Teledyne Isotope Flight Acceptance Schedule (Random Only) with no deviation from normal generator functional output. Radiographic analysis and power tests before and after the vibration test indicated no change in the condition of the generator. The work was conducted in the Alpha Fuels Environmental Test Facility at Mound Laboratory

  2. Flight Test Techniques

    Science.gov (United States)

    1989-01-01

    the airframe for col1A 300 jauges pour un essal d𔄀preuve a ground "proof test" with a 0.8 charge, au sol A charge 0,8 recalant ce modile ; to update...the model. 200 among these 200 de ces jauges ont 6t6 cibl~es bonnes gauges had been wired to be "airworthy", de vol mats le domaine de vol a 4t6 but

  3. The Shock and Vibration Bulletin. Part 3. Skylab, Vibration Testing and Analysis

    Science.gov (United States)

    1973-06-01

    SPECTRA D, 0. Smallwood , Sandia Laboratories, Albuquerque, New Mexico and A. F. Witte, Kaman Sciences, Colorado Springs, Colorado A TRANSIENT VIBRATION TEST...TECHNIQUE USING LEAST FAVORABLE RESPONSES D. 0. Smallwood , Sandia Laboratories, Albuquerque, New Mexico PAPERS APPEARING IN PART 2 Structural...form of the time history pdf is REFERENCES determined to be independent of changes in flight condition and sensor location, the 1. Norman Johnson and

  4. Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

    Science.gov (United States)

    Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

    2009-01-01

    Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

  5. Initial Flight Test of the Production Support Flight Control Computers at NASA Dryden Flight Research Center

    Science.gov (United States)

    Carter, John; Stephenson, Mark

    1999-01-01

    The NASA Dryden Flight Research Center has completed the initial flight test of a modified set of F/A-18 flight control computers that gives the aircraft a research control law capability. The production support flight control computers (PSFCC) provide an increased capability for flight research in the control law, handling qualities, and flight systems areas. The PSFCC feature a research flight control processor that is "piggybacked" onto the baseline F/A-18 flight control system. This research processor allows for pilot selection of research control law operation in flight. To validate flight operation, a replication of a standard F/A-18 control law was programmed into the research processor and flight-tested over a limited envelope. This paper provides a brief description of the system, summarizes the initial flight test of the PSFCC, and describes future experiments for the PSFCC.

  6. Flight test trajectory control analysis

    Science.gov (United States)

    Walker, R.; Gupta, N.

    1983-01-01

    Recent extensions to optimal control theory applied to meaningful linear models with sufficiently flexible software tools provide powerful techniques for designing flight test trajectory controllers (FTTCs). This report describes the principal steps for systematic development of flight trajectory controllers, which can be summarized as planning, modeling, designing, and validating a trajectory controller. The techniques have been kept as general as possible and should apply to a wide range of problems where quantities must be computed and displayed to a pilot to improve pilot effectiveness and to reduce workload and fatigue. To illustrate the approach, a detailed trajectory guidance law is developed and demonstrated for the F-15 aircraft flying the zoom-and-pushover maneuver.

  7. Vibration and Acoustic Testing for Mars Micromission Spacecraft

    Science.gov (United States)

    Kern, Dennis L.; Scharton, Terry D.

    1999-01-01

    The objective of the Mars Micromission program being managed by the Jet Propulsion Laboratory (JPL) for NASA is to develop a common spacecraft that can carry telecommunications equipment and a variety of science payloads for exploration of Mars. The spacecraft will be capable of carrying robot landers and rovers, cameras, probes, balloons, gliders or aircraft, and telecommunications equipment to Mars at much lower cost than recent NASA Mars missions. The lightweight spacecraft (about 220 Kg mass) will be launched in a cooperative venture with CNES as a TWIN auxiliary payload on the Ariane 5 launch vehicle. Two or more Mars Micromission launches are planned for each Mars launch opportunity, which occur every 26 months. The Mars launch window for the first mission is November 1, 2002 through April 2003, which is planned to be a Mars airplane technology demonstration mission to coincide with the 100 year anniversary of the Kittyhawk flight. Several subsequent launches will create a telecommunications network orbiting Mars, which will provide for continuous communication with lenders and rovers on the Martian surface. Dedicated science payload flights to Mars are slated to start in 2005. This new cheaper and faster approach to Mars exploration calls for innovative approaches to the qualification of the Mars Micromission spacecraft for the Ariane 5 launch vibration and acoustic environments. JPL has in recent years implemented new approaches to spacecraft testing that may be effectively applied to the Mars Micromission. These include 1) force limited vibration testing, 2) combined loads, vibration and modal testing, and 3) direct acoustic testing. JPL has performed nearly 200 force limited vibration tests in the past 9 years; several of the tests were on spacecraft and large instruments, including the Cassini and Deep Space One spacecraft. Force limiting, which measures and limits the spacecraft base reaction force using triaxial force gages sandwiched between the

  8. Flight Test of an Intelligent Flight-Control System

    Science.gov (United States)

    Davidson, Ron; Bosworth, John T.; Jacobson, Steven R.; Thomson, Michael Pl; Jorgensen, Charles C.

    2003-01-01

    The F-15 Advanced Controls Technology for Integrated Vehicles (ACTIVE) airplane (see figure) was the test bed for a flight test of an intelligent flight control system (IFCS). This IFCS utilizes a neural network to determine critical stability and control derivatives for a control law, the real-time gains of which are computed by an algorithm that solves the Riccati equation. These derivatives are also used to identify the parameters of a dynamic model of the airplane. The model is used in a model-following portion of the control law, in order to provide specific vehicle handling characteristics. The flight test of the IFCS marks the initiation of the Intelligent Flight Control System Advanced Concept Program (IFCS ACP), which is a collaboration between NASA and Boeing Phantom Works. The goals of the IFCS ACP are to (1) develop the concept of a flight-control system that uses neural-network technology to identify aircraft characteristics to provide optimal aircraft performance, (2) develop a self-training neural network to update estimates of aircraft properties in flight, and (3) demonstrate the aforementioned concepts on the F-15 ACTIVE airplane in flight. The activities of the initial IFCS ACP were divided into three Phases, each devoted to the attainment of a different objective. The objective of Phase I was to develop a pre-trained neural network to store and recall the wind-tunnel-based stability and control derivatives of the vehicle. The objective of Phase II was to develop a neural network that can learn how to adjust the stability and control derivatives to account for failures or modeling deficiencies. The objective of Phase III was to develop a flight control system that uses the neural network outputs as a basis for controlling the aircraft. The flight test of the IFCS was performed in stages. In the first stage, the Phase I version of the pre-trained neural network was flown in a passive mode. The neural network software was running using flight data

  9. Destructive vibration test of a concrete structure

    International Nuclear Information System (INIS)

    Chen, C.K.; Czarnecki, R.M.; Scholl, R.E.

    1977-01-01

    Two identical full-scale 4-story reinforced concrete structures were built in 1965-1966 at the Nevada Test Site to investigate their dynamic response behavior to underground nuclear explosions. For eight years following their construction, the structures were the subject of a continuing program of vibration testing, and substantial data has been collected on the elastic response of these structures. In 1974 it was decided to conduct a high-amplitude vibration test that would cause the south structure (free of partitions) to deform beyond its elastic limit and cause major structural damage. Results of the 1974 testing program are summarized

  10. Integrated Vehicle Ground Vibration Testing of Manned Spacecraft: Historical Precedent

    Science.gov (United States)

    Lemke, Paul R.; Tuma, Margaret L.; Askins, Bruce R.

    2008-01-01

    For the first time in nearly 30 years, NASA is developing a new manned space flight launch system. The Ares I will carry crew and cargo to not only the International Space Station, but onward for the future exploration of the Moon and Mars. The Ares I control system and structural designs use complex computer models for their development. An Integrated Vehicle Ground Vibration Test (IVGVT) will validate the efficacy of these computer models. The IVGVT will reduce the technical risk of unexpected conditions that could place the vehicle or crew in jeopardy. The Ares Project Office's Flight and Integrated Test Office commissioned a study to determine how historical programs, such as Saturn and Space Shuttle, validated the structural dynamics of an integrated flight vehicle. The study methodology was to examine the historical record and seek out members of the engineering community who recall the development of historic manned launch vehicles. These records and interviews provided insight into the best practices and lessons learned from these historic development programs. The information that was gathered allowed the creation of timelines of the historic development programs. The timelines trace the programs from the development of test articles through test preparation, test operations, and test data reduction efforts. These timelines also demonstrate how the historical tests fit within their overall vehicle development programs. Finally, the study was able to quantify approximate staffing levels during historic development programs. Using this study, the Flight and Integrated Test Office was able to evaluate the Ares I Integrated Vehicle Ground Vibration Test schedule and workforce budgets in light of the historical precedents to determine if the test had schedule or cost risks associated with it.

  11. The High Level Vibration Test Program

    International Nuclear Information System (INIS)

    Hofmayer, C.H.; Curreri, J.R.; Park, Y.J.; Kato, W.Y.; Kawakami, S.

    1989-01-01

    As part of cooperative agreements between the United States and Japan, tests have been performed on the seismic vibration table at the Tadotsu Engineering Laboratory of Nuclear Power Engineering Test Center (NUPEC) in Japan. The objective of the test program was to use the NUPEC vibration table to drive large diameter nuclear power piping to substantial plastic strain with an earthquake excitation and to compare the results with state-of-the-art analysis of the problem. The test model was designed by modifying the 1/2.5 scale model of the PWR primary coolant loop. Elastic and inelastic seismic response behavior of the test model was measured in a number of test runs with an increasing excitation input level up to the limit of the vibration table. In the maximum input condition, large dynamic plastic strains were obtained in the piping. Crack initiation was detected following the second maximum excitation run. The test model was subjected to a maximum acceleration well beyond what nuclear power plants are designed to withstand. This paper describes the overall plan, input motion development, test procedure, test results and comparisons with pre-test analysis. 4 refs., 16 figs., 2 tabs

  12. The High Level Vibration Test program

    International Nuclear Information System (INIS)

    Hofmayer, C.H.; Curreri, J.R.; Park, Y.J.; Kato, W.Y.; Kawakami, S.

    1990-01-01

    As part of cooperative agreements between the United States and Japan, tests have been performed on the seismic vibration table at the Tadotsu Engineering Laboratory of Nuclear Power Engineering Test Center (NUPEC) in Japan. The objective of the test program was to use the NUPEC vibration table to drive large diameter nuclear power piping to substantial plastic strain with an earthquake excitation and to compare the results with state-of-the-art analysis of the problem. The test model was designed by modifying the 1/2.5 scale model of the pressurized water reactor primary coolant loop. Elastic and inelastic seismic response behavior of the test model was measured in a number of test runs with an increasing excitation input level up to the limit of the vibration table. In the maximum input condition, large dynamic plastic strains were obtained in the piping. Crack initiation was detected following the second maximum excitation run. The test model was subjected to a maximum acceleration well beyond what nuclear power plants are designed to withstand. This paper describes the overall plan, input motion development, test procedure, test results and comparisons with pre-test analysis

  13. Force Limited Random Vibration Test of TESS Camera Mass Model

    Science.gov (United States)

    Karlicek, Alexandra; Hwang, James Ho-Jin; Rey, Justin J.

    2015-01-01

    The Transiting Exoplanet Survey Satellite (TESS) is a spaceborne instrument consisting of four wide field-of-view-CCD cameras dedicated to the discovery of exoplanets around the brightest stars. As part of the environmental testing campaign, force limiting was used to simulate a realistic random vibration launch environment. While the force limit vibration test method is a standard approach used at multiple institutions including Jet Propulsion Laboratory (JPL), NASA Goddard Space Flight Center (GSFC), European Space Research and Technology Center (ESTEC), and Japan Aerospace Exploration Agency (JAXA), it is still difficult to find an actual implementation process in the literature. This paper describes the step-by-step process on how the force limit method was developed and applied on the TESS camera mass model. The process description includes the design of special fixtures to mount the test article for properly installing force transducers, development of the force spectral density using the semi-empirical method, estimation of the fuzzy factor (C2) based on the mass ratio between the supporting structure and the test article, subsequent validating of the C2 factor during the vibration test, and calculation of the C.G. accelerations using the Root Mean Square (RMS) reaction force in the spectral domain and the peak reaction force in the time domain.

  14. The high level vibration test program

    International Nuclear Information System (INIS)

    Hofmayer, C.H.; Curreri, J.R.; Park, Y.J.; Kato, W.Y.; Kawakami, S.

    1989-01-01

    As part of cooperative agreements between the US and Japan, tests have been performed on the seismic vibration table at the Tadotsu Engineering Laboratory of Nuclear Power Engineering Test Center (NUPEC) in Japan. The objective of the test program was to use the NUPEC vibration table to drive large diameter nuclear power piping to substantial plastic strain with an earthquake excitation and to compare the results with state-of-the-art analysis of the problem. The test model was subjected to a maximum acceleration well beyond what nuclear power plants are designed to withstand. A modified earthquake excitation was applied and the excitation level was increased carefully to minimize the cumulative fatigue damage due to the intermediate level excitations. Since the piping was pressurized, and the high level earthquake excitation was repeated several times, it was possible to investigate the effects of ratchetting and fatigue as well. Elastic and inelastic seismic response behavior of the test model was measured in a number of test runs with an increasing excitation input level up to the limit of the vibration table. In the maximum input condition, large dynamic plastic strains were obtained in the piping. Crack initiation was detected following the second maximum excitation run. Crack growth was carefully monitored during the next two additional maximum excitation runs. The final test resulted in a maximum crack depth of approximately 94% of the wall thickness. The HLVT (high level vibration test) program has enhanced understanding of the behavior of piping systems under severe earthquake loading. As in other tests to failure of piping components, it has demonstrated significant seismic margin in nuclear power plant piping

  15. Rotationally Adaptive Flight Test Surface

    Science.gov (United States)

    Barrett, Ron

    1999-01-01

    Research on a new design of flutter exciter vane using adaptive materials was conducted. This novel design is based on all-moving aerodynamic surface technology and consists of a structurally stiff main spar, a series of piezoelectric actuator elements and an aerodynamic shell which is pivoted around the main spar. The work was built upon the current missile-type all-moving surface designs and change them so they are better suited for flutter excitation through the transonic flight regime. The first portion of research will be centered on aerodynamic and structural modeling of the system. USAF DatCom and vortex lattice codes was used to capture the fundamental aerodynamics of the vane. Finite element codes and laminated plate theory and virtual work analyses will be used to structurally model the aerodynamic vane and wing tip. Following the basic modeling, a flutter test vane was designed. Each component within the structure was designed to meet the design loads. After the design loads are met, then the deflections will be maximized and the internal structure will be laid out. In addition to the structure, a basic electrical control network will be designed which will be capable of driving a scaled exciter vane. The third and final stage of main investigation involved the fabrication of a 1/4 scale vane. This scaled vane was used to verify kinematics and structural mechanics theories on all-moving actuation. Following assembly, a series of bench tests was conducted to determine frequency response, electrical characteristics, mechanical and kinematic properties. Test results indicate peak-to-peak deflections of 1.1 deg with a corner frequency of just over 130 Hz.

  16. Environmental Tests of the Flight GLAST LAT Tracker Towers

    Energy Technology Data Exchange (ETDEWEB)

    Bagagli, R.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Belli, F.; Borden, T.; Brez, A.; Brigida, M.; Caliandro, G.A.; Cecchi, C.; Cohen-Tanugi, J.; Angelis, A.De; Drell, P.; Favuzzi, C.; Fusco, P.; Gargano, F.; Germani, S.; Giglietto, N.; Giordano, F.; Goodman, J.; Himel, T.

    2008-03-12

    The Gamma-ray Large Area Space telescope (GLAST) is a gamma-ray satellite scheduled for launch in 2008. Before the assembly of the Tracker subsystem of the Large Area Telescope (LAT) science instrument of GLAST, every component (tray) and module (tower) has been subjected to extensive ground testing required to ensure successful launch and on-orbit operation. This paper describes the sequence and results of the environmental tests performed on an engineering model and all the flight hardware of the GLAST LAT Tracker. Environmental tests include vibration testing, thermal cycles and thermal-vacuum cycles of every tray and tower as well as the verification of their electrical performance.

  17. Flight Test Maneuvers for Efficient Aerodynamic Modeling

    Science.gov (United States)

    Morelli, Eugene A.

    2011-01-01

    Novel flight test maneuvers for efficient aerodynamic modeling were developed and demonstrated in flight. Orthogonal optimized multi-sine inputs were applied to aircraft control surfaces to excite aircraft dynamic response in all six degrees of freedom simultaneously while keeping the aircraft close to chosen reference flight conditions. Each maneuver was designed for a specific modeling task that cannot be adequately or efficiently accomplished using conventional flight test maneuvers. All of the new maneuvers were first described and explained, then demonstrated on a subscale jet transport aircraft in flight. Real-time and post-flight modeling results obtained using equation-error parameter estimation in the frequency domain were used to show the effectiveness and efficiency of the new maneuvers, as well as the quality of the aerodynamic models that can be identified from the resultant flight data.

  18. Flight Test Approach to Adaptive Control Research

    Science.gov (United States)

    Pavlock, Kate Maureen; Less, James L.; Larson, David Nils

    2011-01-01

    The National Aeronautics and Space Administration s Dryden Flight Research Center completed flight testing of adaptive controls research on a full-scale F-18 testbed. The validation of adaptive controls has the potential to enhance safety in the presence of adverse conditions such as structural damage or control surface failures. This paper describes the research interface architecture, risk mitigations, flight test approach and lessons learned of adaptive controls research.

  19. Ground vibration test results of a JetStar airplane using impulsive sine excitation

    Science.gov (United States)

    Kehoe, Michael W.; Voracek, David F.

    1989-01-01

    Structural excitation is important for both ground vibration and flight flutter testing. The structural responses caused by this excitation are analyzed to determine frequency, damping, and mode shape information. Many excitation waveforms have been used throughout the years. The use of impulsive sine (sin omega t)/omega t as an excitation waveform for ground vibration testing and the advantages of using this waveform for flight flutter testing are discussed. The ground vibration test results of a modified JetStar airplane using impulsive sine as an excitation waveform are compared with the test results of the same airplane using multiple-input random excitation. The results indicated that the structure was sufficiently excited using the impulsive sine waveform. Comparisons of input force spectrums, mode shape plots, and frequency and damping values for the two methods of excitation are presented.

  20. FT 3 Flight Test Cards for Export

    Science.gov (United States)

    Marston, Michael L.

    2015-01-01

    These flight test cards will be made available to stakeholders who participated in FT3. NASA entered into the relationship with our stakeholders, including the FAA, to develop requirements that will lead to routine flights of unmanned aircraft systems flying in the national airspace system.

  1. Ares I-X Flight Test Philosophy

    Science.gov (United States)

    Davis, S. R.; Tuma, M. L.; Heitzman, K.

    2007-01-01

    In response to the Vision for Space Exploration, the National Aeronautics and Space Administration (NASA) has defined a new space exploration architecture to return humans to the Moon and prepare for human exploration of Mars. One of the first new developments will be the Ares I Crew Launch Vehicle (CLV), which will carry the Orion Crew Exploration Vehicle (CEV), into Low Earth Orbit (LEO) to support International Space Station (ISS) missions and, later, support lunar missions. As part of Ares I development, NASA will perform a series of Ares I flight tests. The tests will provide data that will inform the engineering and design process and verify the flight hardware and software. The data gained from the flight tests will be used to certify the new Ares/Orion vehicle for human space flight. The primary objectives of this first flight test (Ares I-X) are the following: Demonstrate control of a dynamically similar integrated Ares CLV/Orion CEV using Ares CLV ascent control algorithms; Perform an in-flight separation/staging event between an Ares I-similar First Stage and a representative Upper Stage; Demonstrate assembly and recovery of a new Ares CLV-like First Stage element at Kennedy Space Center (KSC); Demonstrate First Stage separation sequencing, and quantify First Stage atmospheric entry dynamics and parachute performance; and Characterize the magnitude of the integrated vehicle roll torque throughout the First Stage (powered) flight. This paper will provide an overview of the Ares I-X flight test process and details of the individual flight tests.

  2. Laser Obstacle Detection System Flight Testing

    National Research Council Canada - National Science Library

    Davis, Timothy

    2003-01-01

    ...). The Aviation Applied Technology Directorate (AATD) was contracted to mount the HELLAS sensor on the nose of a UH-60L Blackhawk helicopter and to conduct flight tests to evaluate the HELLAS obstacle detection sensor...

  3. Writing executable assertions to test flight software

    Science.gov (United States)

    Mahmood, A.; Andrews, D. M.; Mccluskey, E. J.

    1984-01-01

    An executable assertion is a logical statement about the variables or a block of code. If there is no error during execution, the assertion statement results in a true value. Executable assertions can be used for dynamic testing of software. They can be employed for validation during the design phase, and exception and error detection during the operation phase. The present investigation is concerned with the problem of writing executable assertions, taking into account the use of assertions for testing flight software. They can be employed for validation during the design phase, and for exception handling and error detection during the operation phase The digital flight control system and the flight control software are discussed. The considered system provides autopilot and flight director modes of operation for automatic and manual control of the aircraft during all phases of flight. Attention is given to techniques for writing and using assertions to test flight software, an experimental setup to test flight software, and language features to support efficient use of assertions.

  4. Astronaut Gordon Cooper during flight tests

    Science.gov (United States)

    1963-01-01

    Astronaut L. Gordon Cooper, prime pilot for the Mercury-Atlas 9 mission, relaxes while waiting for weight and balance tests to begin (03974); Cooper prior to entering the Mercury Spacecraft for a series of simulated flight tests. During these tests NASA doctors, engineers and technicians monitor Cooper's performance (03975); Cooper undergoing suit pressurization tests (03976).

  5. Orion Exploration Flight Test Post-Flight Inspection and Analysis

    Science.gov (United States)

    Miller, J. E.; Berger, E. L.; Bohl, W. E.; Christiansen, E. L.; Davis, B. A.; Deighton, K. D.; Enriquez, P. A.; Garcia, M. A.; Hyde, J. L.; Oliveras, O. M.

    2017-01-01

    The principal mechanism for developing orbital debris environment models, is to make observations of larger pieces of debris in the range of several centimeters and greater using radar and optical techniques. For particles that are smaller than this threshold, breakup and migration models of particles to returned surfaces in lower orbit are relied upon to quantify the flux. This reliance on models to derive spatial densities of particles that are of critical importance to spacecraft make the unique nature of the EFT-1's return surface a valuable metric. To this end detailed post-flight inspections have been performed of the returned EFT-1 backshell, and the inspections identified six candidate impact sites that were not present during the pre-flight inspections. This paper describes the post-flight analysis efforts to characterize the EFT-1 mission craters. This effort included ground based testing to understand small particle impact craters in the thermal protection material, the pre- and post-flight inspection, the crater analysis using optical, X-ray computed tomography (CT) and scanning electron microscope (SEM) techniques, and numerical simulations.

  6. Development of a flight software testing methodology

    Science.gov (United States)

    Mccluskey, E. J.; Andrews, D. M.

    1985-01-01

    The research to develop a testing methodology for flight software is described. An experiment was conducted in using assertions to dynamically test digital flight control software. The experiment showed that 87% of typical errors introduced into the program would be detected by assertions. Detailed analysis of the test data showed that the number of assertions needed to detect those errors could be reduced to a minimal set. The analysis also revealed that the most effective assertions tested program parameters that provided greater indirect (collateral) testing of other parameters. In addition, a prototype watchdog task system was built to evaluate the effectiveness of executing assertions in parallel by using the multitasking features of Ada.

  7. Fused Reality for Enhanced Flight Test Capabilities

    Science.gov (United States)

    Bachelder, Ed; Klyde, David

    2011-01-01

    The feasibility of using Fused Reality-based simulation technology to enhance flight test capabilities has been investigated. In terms of relevancy to piloted evaluation, there remains no substitute for actual flight tests, even when considering the fidelity and effectiveness of modern ground-based simulators. In addition to real-world cueing (vestibular, visual, aural, environmental, etc.), flight tests provide subtle but key intangibles that cannot be duplicated in a ground-based simulator. There is, however, a cost to be paid for the benefits of flight in terms of budget, mission complexity, and safety, including the need for ground and control-room personnel, additional aircraft, etc. A Fused Reality(tm) (FR) Flight system was developed that allows a virtual environment to be integrated with the test aircraft so that tasks such as aerial refueling, formation flying, or approach and landing can be accomplished without additional aircraft resources or the risk of operating in close proximity to the ground or other aircraft. Furthermore, the dynamic motions of the simulated objects can be directly correlated with the responses of the test aircraft. The FR Flight system will allow real-time observation of, and manual interaction with, the cockpit environment that serves as a frame for the virtual out-the-window scene.

  8. Free Flight Rotorcraft Flight Test Vehicle Technology Development

    Science.gov (United States)

    Hodges, W. Todd; Walker, Gregory W.

    1994-01-01

    A rotary wing, unmanned air vehicle (UAV) is being developed as a research tool at the NASA Langley Research Center by the U.S. Army and NASA. This development program is intended to provide the rotorcraft research community an intermediate step between rotorcraft wind tunnel testing and full scale manned flight testing. The technologies under development for this vehicle are: adaptive electronic flight control systems incorporating artificial intelligence (AI) techniques, small-light weight sophisticated sensors, advanced telepresence-telerobotics systems and rotary wing UAV operational procedures. This paper briefly describes the system's requirements and the techniques used to integrate the various technologies to meet these requirements. The paper also discusses the status of the development effort. In addition to the original aeromechanics research mission, the technology development effort has generated a great deal of interest in the UAV community for related spin-off applications, as briefly described at the end of the paper. In some cases the technologies under development in the free flight program are critical to the ability to perform some applications.

  9. Fuel Subsystems Flight Test Handbook

    Science.gov (United States)

    1981-12-01

    detailed, accessible .-ltand complete test records for his own protection and for the benefit of his successor in case of promotion, transfer or...and pilot display of fuel quantity, low level warning and a " Bingo " fudl warning. 3.0 TEST OBJECT1VES: ACTION Orriclc. On POUTION•’PHONWE [ DATE PCR...TIS No. 46, paragraph 3.11 3.6 To demonstrate that the low level and bingo warning system are consistent L •and meet the requirements of paragraph

  10. 46 CFR 162.050-37 - Vibration test.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Vibration test. 162.050-37 Section 162.050-37 Shipping...: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Pollution Prevention Equipment § 162.050-37 Vibration test. (a... paragraph (b) of this section. The test must be performed at an independent laboratory that has the...

  11. Peri-prosthetic fracture vibration testing

    Energy Technology Data Exchange (ETDEWEB)

    Cruce, Jesse R [Los Alamos National Laboratory; Erwin, Jenny R [Los Alamos National Laboratory; Remick, Kevin R [Los Alamos National Laboratory; Cornwell, Phillip J [Los Alamos National Laboratory; Menegini, R. Michael [INDIANA UNIV.; Racanelli, Joe [STRYKER ORTHOPARDICS

    2010-11-08

    The purpose of this study was to establish a test setup and vibration analysis method to predict femoral stem seating and prevent bone fracture using accelerometer and force response data from an instrumented stem and impactor. This study builds upon earlier studies to identify a means to supplement a surgeon's tactile and auditory senses by using damage identification techniques normally used for civil and mechanical structures. Testing was conducted using foam cortical shell sawbones prepared for stems of different geometries. Each stem was instrumented with an accelerometer. Two impactor designs were compared: a monolithic impactor and a two-piece impactor, each with an integrated load cell and accelerometer. Acceleration and force measurements were taken in the direction of impaction. Comparisons between different methods of applying an impacting force were made, including a drop tower and a surgical hammer. The effect of varying compliance on the data was also investigated. The ultimate goal of this study was to assist in the design of an integrated portable data acquisition system capable of being used in future cadaveric testing. This paper will discuss the experimental setup and the subsequent results of the comparisons made between impactors, prosthetic geometries, compliances, and impact methods. The results of this study can be used for both future replicate testing as well as in a cadaveric environment.

  12. The development of a Flight Test Engineer's Workstation for the Automated Flight Test Management System

    Science.gov (United States)

    Tartt, David M.; Hewett, Marle D.; Duke, Eugene L.; Cooper, James A.; Brumbaugh, Randal W.

    1989-01-01

    The Automated Flight Test Management System (ATMS) is being developed as part of the NASA Aircraft Automation Program. This program focuses on the application of interdisciplinary state-of-the-art technology in artificial intelligence, control theory, and systems methodology to problems of operating and flight testing high-performance aircraft. The development of a Flight Test Engineer's Workstation (FTEWS) is presented, with a detailed description of the system, technical details, and future planned developments. The goal of the FTEWS is to provide flight test engineers and project officers with an automated computer environment for planning, scheduling, and performing flight test programs. The FTEWS system is an outgrowth of the development of ATMS and is an implementation of a component of ATMS on SUN workstations.

  13. Threshold Assessment of Gear Diagnostic Tools on Flight and Test Rig Data

    Science.gov (United States)

    Dempsey, Paula J.; Mosher, Marianne; Huff, Edward M.

    2003-01-01

    A method for defining thresholds for vibration-based algorithms that provides the minimum number of false alarms while maintaining sensitivity to gear damage was developed. This analysis focused on two vibration based gear damage detection algorithms, FM4 and MSA. This method was developed using vibration data collected during surface fatigue tests performed in a spur gearbox rig. The thresholds were defined based on damage progression during tests with damage. The thresholds false alarm rates were then evaluated on spur gear tests without damage. Next, the same thresholds were applied to flight data from an OH-58 helicopter transmission. Results showed that thresholds defined in test rigs can be used to define thresholds in flight to correctly classify the transmission operation as normal.

  14. Flight Control of Biomimetic Air Vehicles Using Vibrational Control and Averaging

    Science.gov (United States)

    Tahmasian, Sevak; Woolsey, Craig A.

    2017-08-01

    A combination of vibrational inputs and state feedback is applied to control the flight of a biomimetic air vehicle. First, a control strategy is developed for longitudinal flight, using a quasi-steady aerodynamic model and neglecting wing inertial effects. Vertical and forward motion is controlled by modulating the wings' stroke and feather angles, respectively. Stabilizing control parameter values are determined using the time-averaged dynamic model. Simulations of a system resembling a hawkmoth show that the proposed controller can overcome modeling error associated with the wing inertia and small parameter uncertainties when following a prescribed trajectory. After introducing the approach through an application to longitudinal flight, the control strategy is extended to address flight in three-dimensional space.

  15. Vibration detection with 100 Hz GPS PVAT during a dynamic flight

    Science.gov (United States)

    Bischof, Christian; Schön, Steffen

    2017-06-01

    This investigation gives insights into real 100 Hz GPS velocity and acceleration estimates from a position, velocity, acceleration and time (PVAT) extended Kalman filter (EKF) during a highly dynamic flight trial with a Dornier Do 128-6 aircraft. We investigated the accelerations during take-off, landing and wing shaking manoeuvres in order to compare the vibration behaviour of the given aircraft determined by means of GPS against an onboard IMU. We found that 100 Hz GPS acceleration is useful for characterising vibrations and giving valuable insights during highly dynamic flights. Potential latency of 0.12 s and amplitude misestimation of up to 80% w.r.t. the reference amplitude occur that should be determined beforehand in order to correctly interpret the results.

  16. Data of piezoelectric vibration energy harvesting of a bridge undergoing vibration testing and train passage

    Directory of Open Access Journals (Sweden)

    Paul Cahill

    2018-04-01

    Full Text Available The data presented in this article is in relation to the research article “Vibration energy harvesting based monitoring of an operational bridge undergoing forced vibration and train passage” Cahill et al. (2018 [1]. The article provides data on the full-scale bridge testing using piezoelectric vibration energy harvesters on Pershagen Bridge, Sweden. The bridge is actively excited via a swept sinusoidal input. During the testing, the bridge remains operational and train passages continue. The test recordings include the voltage responses obtained from the vibration energy harvesters during these tests and train passages. The original dataset is made available to encourage the use of energy harvesting for Structural Health Monitoring.

  17. Research on the design of fixture for motor vibration test

    Science.gov (United States)

    Shen, W. X.; Ma, W. S.; Zhang, L. W.

    2018-03-01

    The vibration reliability of the new energy automobile motor plays a very important role in driving safety, so it is very important to test the vibration durability of the motor. In the vibration test process, the fixture is very important, simulated road spectrum signal vibration can be transmitted without distortion to the motor through the fixture, fixture design directly affect the result of vibration endurance test. On the basis of new energy electric vehicle motor concrete structure, Two fixture design and fixture installation schemes for lateral cantilever type and base bearing type are put forward in this article, the selection of material, weighting process, middle alignment process and manufacturing process are summarized.The modal analysis and frequency response calculation of the fixture are carried out in this design, combine with influence caused by fixture height and structure profile on response frequency, the response frequency of each order of the fixture is calculated, then ultimately achieve the purpose of guiding the design.

  18. Investigation of Concrete Floor Vibration Using Heel-Drop Test

    Science.gov (United States)

    Azaman, N. A. Mohd; Ghafar, N. H. Abd; Azhar, A. F.; Fauzi, A. A.; Ismail, H. A.; Syed Idrus, S. S.; Mokhjar, S. S.; Hamid, F. F. Abd

    2018-04-01

    In recent years, there is an increased in floor vibration problems of structures like residential and commercial building. Vibration is defined as a serviceability issue related to the comfort of the occupant or damage equipment. Human activities are the main source of vibration in the building and it could affect the human comfort and annoyance of residents in the building when the vibration exceed the recommend level. A new building, Madrasah Tahfiz located at Yong Peng have vibration problem when load subjected on the first floor of the building. However, the limitation of vibration occurs on building is unknown. Therefore, testing is needed to determine the vibration behaviour (frequency, damping ratio and mode shape) of the building. Heel-drop with pace 2Hz was used in field measurement to obtain the vibration response. Since, the heel-drop test results would vary in light of person performance, test are carried out three time to reduce uncertainty. Natural frequency from Frequency Response Function analysis (FRF) is 17.4Hz, 16.8, 17.4Hz respectively for each test.

  19. Integrated Test and Evaluation (ITE) Flight Test Series 4

    Science.gov (United States)

    Marston, Michael

    2016-01-01

    The integrated Flight Test 4 (FT4) will gather data for the UAS researchers Sense and Avoid systems (referred to as Detect and Avoid in the RTCA SC 228 ToR) algorithms and pilot displays for candidate UAS systems in a relevant environment. The technical goals of FT4 are to: 1) perform end-to-end traffic encounter test of pilot guidance generated by DAA algorithms; 2) collect data to inform the initial Minimum Operational Performance Standards (MOPS) for Detect and Avoid systems. FT4 objectives and test infrastructure builds from previous UAS project simulations and flight tests. NASA Ames (ARC), NASA Armstrong (AFRC), and NASA Langley (LaRC) Research Centers will share responsibility for conducting the tests, each providing a test lab and critical functionality. UAS-NAS project support and participation on the 2014 flight test of ACAS Xu and DAA Self Separation (SS) significantly contributed to building up infrastructure and procedures for FT3 as well. The DAA Scripted flight test (FT4) will be conducted out of NASA Armstrong over an eight-week period beginning in April 2016.

  20. Free Flight Ground Testing of ADEPT in Advance of the Sounding Rocket One Flight Experiment

    Science.gov (United States)

    Smith, B. P.; Dutta, S.

    2017-01-01

    The Adaptable Deployable Entry and Placement Technology (ADEPT) project will be conducting the first flight test of ADEPT, titled Sounding Rocket One (SR-1), in just two months. The need for this flight test stems from the fact that ADEPT's supersonic dynamic stability has not yet been characterized. The SR-1 flight test will provide critical data describing the flight mechanics of ADEPT in ballistic flight. These data will feed decision making on future ADEPT mission designs. This presentation will describe the SR-1 scientific data products, possible flight test outcomes, and the implications of those outcomes on future ADEPT development. In addition, this presentation will describe free-flight ground testing performed in advance of the flight test. A subsonic flight dynamics test conducted at the Vertical Spin Tunnel located at NASA Langley Research Center provided subsonic flight dynamics data at high and low altitudes for multiple center of mass (CoM) locations. A ballistic range test at the Hypervelocity Free Flight Aerodynamics Facility (HFFAF) located at NASA Ames Research Center provided supersonic flight dynamics data at low supersonic Mach numbers. Execution and outcomes of these tests will be discussed. Finally, a hypothesized trajectory estimate for the SR-1 flight will be presented.

  1. The Cryogenic Test Bed experiments: Cryogenic heat pipe flight experiment CRYOHP (STS-53). Cryogenic two phase flight experiment CRYOTP (STS-62). Cryogenic flexible diode flight experiment CRYOFD

    Science.gov (United States)

    Thienel, Lee; Stouffer, Chuck

    1995-09-01

    This paper presents an overview of the Cryogenic Test Bed (CTB) experiments including experiment results, integration techniques used, and lessons learned during integration, test and flight phases of the Cryogenic Heat Pipe Flight Experiment (STS-53) and the Cryogenic Two Phase Flight Experiment (OAST-2, STS-62). We will also discuss the Cryogenic Flexible Diode Heat Pipe (CRYOFD) experiment which will fly in the 1996/97 time frame and the fourth flight of the CTB which will fly in the 1997/98 time frame. The two missions tested two oxygen axially grooved heat pipes, a nitrogen fibrous wick heat pipe and a 2-methylpentane phase change material thermal storage unit. Techniques were found for solving problems with vibration from the cryo-collers transmitted through the compressors and the cold heads, and mounting the heat pipe without introducing parasitic heat leaks. A thermally conductive interface material was selected that would meet the requirements and perform over the temperature range of 55 to 300 K. Problems are discussed with the bi-metallic thermostats used for heater circuit protection and the S-Glass suspension straps originally used to secure the BETSU PCM in the CRYOTP mission. Flight results will be compared to 1-g test results and differences will be discussed.

  2. Implementation and flight tests for the Digital Integrated Automatic Landing System (DIALS). Part 1: Flight software equations, flight test description and selected flight test data

    Science.gov (United States)

    Hueschen, R. M.

    1986-01-01

    Five flight tests of the Digital Automated Landing System (DIALS) were conducted on the Advanced Transport Operating Systems (ATOPS) Transportation Research Vehicle (TSRV) -- a modified Boeing 737 aircraft for advanced controls and displays research. These flight tests were conducted at NASA's Wallops Flight Center using the microwave landing system (MLS) installation on runway 22. This report describes the flight software equations of the DIALS which was designed using modern control theory direct-digital design methods and employed a constant gain Kalman filter. Selected flight test performance data is presented for localizer (runway centerline) capture and track at various intercept angles, for glideslope capture and track of 3, 4.5, and 5 degree glideslopes, for the decrab maneuver, and for the flare maneuver. Data is also presented to illustrate the system performance in the presence of cross, gust, and shear winds. The mean and standard deviation of the peak position errors for localizer capture were, respectively, 24 feet and 26 feet. For mild wind conditions, glideslope and localizer tracking position errors did not exceed, respectively, 5 and 20 feet. For gusty wind conditions (8 to 10 knots), these errors were, respectively, 10 and 30 feet. Ten hands off automatic lands were performed. The standard deviation of the touchdown position and velocity errors from the mean values were, respectively, 244 feet and 0.7 feet/sec.

  3. 14 CFR 21.37 - Flight test pilot.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight test pilot. 21.37 Section 21.37... PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.37 Flight test pilot. Each applicant for a normal... holding an appropriate pilot certificate to make the flight tests required by this part. [Doc. No. 5085...

  4. Automation of Flight Software Regression Testing

    Science.gov (United States)

    Tashakkor, Scott B.

    2016-01-01

    NASA is developing the Space Launch System (SLS) to be a heavy lift launch vehicle supporting human and scientific exploration beyond earth orbit. SLS will have a common core stage, an upper stage, and different permutations of boosters and fairings to perform various crewed or cargo missions. Marshall Space Flight Center (MSFC) is writing the Flight Software (FSW) that will operate the SLS launch vehicle. The FSW is developed in an incremental manner based on "Agile" software techniques. As the FSW is incrementally developed, testing the functionality of the code needs to be performed continually to ensure that the integrity of the software is maintained. Manually testing the functionality on an ever-growing set of requirements and features is not an efficient solution and therefore needs to be done automatically to ensure testing is comprehensive. To support test automation, a framework for a regression test harness has been developed and used on SLS FSW. The test harness provides a modular design approach that can compile or read in the required information specified by the developer of the test. The modularity provides independence between groups of tests and the ability to add and remove tests without disturbing others. This provides the SLS FSW team a time saving feature that is essential to meeting SLS Program technical and programmatic requirements. During development of SLS FSW, this technique has proved to be a useful tool to ensure all requirements have been tested, and that desired functionality is maintained, as changes occur. It also provides a mechanism for developers to check functionality of the code that they have developed. With this system, automation of regression testing is accomplished through a scheduling tool and/or commit hooks. Key advantages of this test harness capability includes execution support for multiple independent test cases, the ability for developers to specify precisely what they are testing and how, the ability to add

  5. Optimization models for flight test scheduling

    Science.gov (United States)

    Holian, Derreck

    with restriction removal is based on heuristic approaches to support the reality of flight test in both solution space and computational time. Exact methods for yielding an optimized solution will be discussed however they are not directly applicable to the flight test problem and therefore have not been included in the system.

  6. Development flight tests of JetStar LFC leading-edge flight test experiment

    Science.gov (United States)

    Fisher, David F.; Fischer, Michael C.

    1987-01-01

    The overall objective of the flight tests on the JetStar aircraft was to demonstrate the effectiveness and reliability of laminar flow control under representative flight conditions. One specific objective was to obtain laminar flow on the JetStar leading-edge test articles for the design and off-design conditions. Another specific objective was to obtain operational experience on a Laminar Flow Control (LFC) leading-edge system in a simulated airline service. This included operational experience with cleaning requirements, the effect of clogging, possible foreign object damage, erosion, and the effects of ice particle and cloud encounters. Results are summarized.

  7. Hydride transport vessel vibration and shock test report

    Energy Technology Data Exchange (ETDEWEB)

    Tipton, D.G.

    1998-06-01

    Sandia National Laboratories performed vibration and shock testing on a Savannah River Hydride Transport Vessel (HTV) which is used for bulk shipments of tritium. This testing is required to qualify the HTV for transport in the H1616 shipping container. The main requirement for shipment in the H1616 is that the contents (in this case the HTV) have a tritium leak rate of less than 1x10{sup {minus}7} cc/sec after being subjected to shock and vibration normally incident to transport. Helium leak tests performed before and after the vibration and shock testing showed that the HTV remained leaktight under the specified conditions. This report documents the tests performed and the test results.

  8. Hydride transport vessel vibration and shock test report

    International Nuclear Information System (INIS)

    Tipton, D.G.

    1998-06-01

    Sandia National Laboratories performed vibration and shock testing on a Savannah River Hydride Transport Vessel (HTV) which is used for bulk shipments of tritium. This testing is required to qualify the HTV for transport in the H1616 shipping container. The main requirement for shipment in the H1616 is that the contents (in this case the HTV) have a tritium leak rate of less than 1x10 -7 cc/sec after being subjected to shock and vibration normally incident to transport. Helium leak tests performed before and after the vibration and shock testing showed that the HTV remained leaktight under the specified conditions. This report documents the tests performed and the test results

  9. UAS-NAS Flight Test Series 3: Test Environment Report

    Science.gov (United States)

    Hoang, Ty; Murphy, Jim; Otto, Neil

    2016-01-01

    The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration in the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability (SSI), Human Systems Integration (HSI), and Communications (Comm), and Certification to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Detect and Avoid (DAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project is conducting a series of human-in-the-loop (HITL) and flight test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity, and

  10. Deducing Electronic Unit Internal Response During a Vibration Test Using a Lumped Parameter Modeling Approach

    Science.gov (United States)

    Van Dyke, Michael B.

    2014-01-01

    During random vibration testing of electronic boxes there is often a desire to know the dynamic response of certain internal printed wiring boards (PWBs) for the purpose of monitoring the response of sensitive hardware or for post-test forensic analysis in support of anomaly investigation. Due to restrictions on internally mounted accelerometers for most flight hardware there is usually no means to empirically observe the internal dynamics of the unit, so one must resort to crude and highly uncertain approximations. One common practice is to apply Miles Equation, which does not account for the coupled response of the board in the chassis, resulting in significant over- or under-prediction. This paper explores the application of simple multiple-degree-of-freedom lumped parameter modeling to predict the coupled random vibration response of the PWBs in their fundamental modes of vibration. A simple tool using this approach could be used during or following a random vibration test to interpret vibration test data from a single external chassis measurement to deduce internal board dynamics by means of a rapid correlation analysis. Such a tool might also be useful in early design stages as a supplemental analysis to a more detailed finite element analysis to quickly prototype and analyze the dynamics of various design iterations. After developing the theoretical basis, a lumped parameter modeling approach is applied to an electronic unit for which both external and internal test vibration response measurements are available for direct comparison. Reasonable correlation of the results demonstrates the potential viability of such an approach. Further development of the preliminary approach presented in this paper will involve correlation with detailed finite element models and additional relevant test data.

  11. Development of seismic technology and reliability based on vibration tests

    International Nuclear Information System (INIS)

    Sasaki, Youichi

    1997-01-01

    This paper deals with some of the vibration tests and investigations on the seismic safety of nuclear power plants (NPPs) in Japan. To ensure the reliability of the seismic safety of nuclear power plants, nuclear power plants in Japan have been designed according to the Technical Guidelines for Aseismic Design of Nuclear Power Plants. This guideline has been developed based on technical date base and findings which were obtained from many vibration tests and investigations. Besides the tests for the guideline, proving tests on seismic reliability of operating nuclear power plants equipment and systems have been carried out. In this paper some vibration tests and their evaluation results are presented. They have crucially contributed to develop the guideline. (J.P.N.)

  12. Development of seismic technology and reliability based on vibration tests

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Youichi [Nuclear Power Engineering Corp., Tokyo (Japan)

    1997-03-01

    This paper deals with some of the vibration tests and investigations on the seismic safety of nuclear power plants (NPPs) in Japan. To ensure the reliability of the seismic safety of nuclear power plants, nuclear power plants in Japan have been designed according to the Technical Guidelines for Aseismic Design of Nuclear Power Plants. This guideline has been developed based on technical date base and findings which were obtained from many vibration tests and investigations. Besides the tests for the guideline, proving tests on seismic reliability of operating nuclear power plants equipment and systems have been carried out. In this paper some vibration tests and their evaluation results are presented. They have crucially contributed to develop the guideline. (J.P.N.)

  13. The Orion Exploration Flight Test Post Flight Solid Particle Flight Environment Inspection and Analysis

    Science.gov (United States)

    Miller, Joshua E.

    2016-01-01

    Orbital debris in the millimeter size range can pose a hazard to current and planned spacecraft due to the high relative impact speeds in Earth orbit. Fortunately, orbital debris has a relatively short life at lower altitudes due to atmospheric effects; however, at higher altitudes orbital debris can survive much longer and has resulted in a band of high flux around 700 to 1,500 km above the surface of the Earth. While large orbital debris objects are tracked via ground based observation, little information can be gathered about small particles except by returned surfaces, which until the Orion Exploration Flight Test number one (EFT-1), has only been possible for lower altitudes (400 to 500 km). The EFT-1 crew module backshell, which used a porous, ceramic tile system with surface coatings, has been inspected post-flight for potential micrometeoroid and orbital debris (MMOD) damage. This paper describes the pre- and post-flight activities of inspection, identification and analysis of six candidate MMOD impact craters from the EFT-1 mission.

  14. Imaging Sensor Flight and Test Equipment Software

    Science.gov (United States)

    Freestone, Kathleen; Simeone, Louis; Robertson, Byran; Frankford, Maytha; Trice, David; Wallace, Kevin; Wilkerson, DeLisa

    2007-01-01

    The Lightning Imaging Sensor (LIS) is one of the components onboard the Tropical Rainfall Measuring Mission (TRMM) satellite, and was designed to detect and locate lightning over the tropics. The LIS flight code was developed to run on a single onboard digital signal processor, and has operated the LIS instrument since 1997 when the TRMM satellite was launched. The software provides controller functions to the LIS Real-Time Event Processor (RTEP) and onboard heaters, collects the lightning event data from the RTEP, compresses and formats the data for downlink to the satellite, collects housekeeping data and formats the data for downlink to the satellite, provides command processing and interface to the spacecraft communications and data bus, and provides watchdog functions for error detection. The Special Test Equipment (STE) software was designed to operate specific test equipment used to support the LIS hardware through development, calibration, qualification, and integration with the TRMM spacecraft. The STE software provides the capability to control instrument activation, commanding (including both data formatting and user interfacing), data collection, decompression, and display and image simulation. The LIS STE code was developed for the DOS operating system in the C programming language. Because of the many unique data formats implemented by the flight instrument, the STE software was required to comprehend the same formats, and translate them for the test operator. The hardware interfaces to the LIS instrument using both commercial and custom computer boards, requiring that the STE code integrate this variety into a working system. In addition, the requirement to provide RTEP test capability dictated the need to provide simulations of background image data with short-duration lightning transients superimposed. This led to the development of unique code used to control the location, intensity, and variation above background for simulated lightning strikes

  15. Correlation of finite element free vibration predictions using random vibration test data. M.S. Thesis - Cleveland State Univ.

    Science.gov (United States)

    Chambers, Jeffrey A.

    1994-01-01

    Finite element analysis is regularly used during the engineering cycle of mechanical systems to predict the response to static, thermal, and dynamic loads. The finite element model (FEM) used to represent the system is often correlated with physical test results to determine the validity of analytical results provided. Results from dynamic testing provide one means for performing this correlation. One of the most common methods of measuring accuracy is by classical modal testing, whereby vibratory mode shapes are compared to mode shapes provided by finite element analysis. The degree of correlation between the test and analytical mode shapes can be shown mathematically using the cross orthogonality check. A great deal of time and effort can be exhausted in generating the set of test acquired mode shapes needed for the cross orthogonality check. In most situations response data from vibration tests are digitally processed to generate the mode shapes from a combination of modal parameters, forcing functions, and recorded response data. An alternate method is proposed in which the same correlation of analytical and test acquired mode shapes can be achieved without conducting the modal survey. Instead a procedure is detailed in which a minimum of test information, specifically the acceleration response data from a random vibration test, is used to generate a set of equivalent local accelerations to be applied to the reduced analytical model at discrete points corresponding to the test measurement locations. The static solution of the analytical model then produces a set of deformations that once normalized can be used to represent the test acquired mode shapes in the cross orthogonality relation. The method proposed has been shown to provide accurate results for both a simple analytical model as well as a complex space flight structure.

  16. Fused Reality for Enhanced Flight Test Capabilities, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — While modern ground-based flight simulators continue to improve in fidelity and effectiveness, there remains no substitute for flight test evaluations. In addition...

  17. Mechanical system diagnostics using vibration testing techniques

    Science.gov (United States)

    Mcleod, Catherine D.; Raju, P. K.; Crocker, M. J.

    1990-01-01

    The 'Cepstrum' technique of vibration-path identification allows the recovery of the transfer function of a system with little knowledge as to its excitation force, by means of a mathematical manipulation of the system output in conjunction with subtraction of part of the output and suitable signal processing. An experimental program has been conducted to evaluate the usefulness of this technique in the cases of simple, cantilever-beam and free-free plate structures as well as in that of a complex mechanical system. On the basis of the transfer functions thus recovered, it was possible to evaluate the shifts in the resonance frequencies of a structure due to the presence of defects.

  18. Selected Flight Test Results for Online Learning Neural Network-Based Flight Control System

    Science.gov (United States)

    Williams-Hayes, Peggy S.

    2004-01-01

    The NASA F-15 Intelligent Flight Control System project team developed a series of flight control concepts designed to demonstrate neural network-based adaptive controller benefits, with the objective to develop and flight-test control systems using neural network technology to optimize aircraft performance under nominal conditions and stabilize the aircraft under failure conditions. This report presents flight-test results for an adaptive controller using stability and control derivative values from an online learning neural network. A dynamic cell structure neural network is used in conjunction with a real-time parameter identification algorithm to estimate aerodynamic stability and control derivative increments to baseline aerodynamic derivatives in flight. This open-loop flight test set was performed in preparation for a future phase in which the learning neural network and parameter identification algorithm output would provide the flight controller with aerodynamic stability and control derivative updates in near real time. Two flight maneuvers are analyzed - pitch frequency sweep and automated flight-test maneuver designed to optimally excite the parameter identification algorithm in all axes. Frequency responses generated from flight data are compared to those obtained from nonlinear simulation runs. Flight data examination shows that addition of flight-identified aerodynamic derivative increments into the simulation improved aircraft pitch handling qualities.

  19. Apollo experience report: Development flight instrumentation. [telemetry equipment for space flight test program

    Science.gov (United States)

    Farmer, N. B.

    1974-01-01

    Development flight instrumentation was delivered for 25 Apollo vehicles as Government-furnished equipment. The problems and philosophies of an activity that was concerned with supplying telemetry equipment to a space-flight test program are discussed. Equipment delivery dates, system-design details, and flight-performance information for each mission also are included.

  20. Mars Science Laboratory Flight Software Internal Testing

    Science.gov (United States)

    Jones, Justin D.; Lam, Danny

    2011-01-01

    The Mars Science Laboratory (MSL) team is sending the rover, Curiosity, to Mars, and therefore is physically and technically complex. During my stay, I have assisted the MSL Flight Software (FSW) team in implementing functional test scripts to ensure that the FSW performs to the best of its abilities. There are a large number of FSW requirements that have been written up for implementation; however I have only been assigned a few sections of these requirements. There are many stages within testing; one of the early stages is FSW Internal Testing (FIT). The FIT team can accomplish this with simulation software and the MSL Test Automation Kit (MTAK). MTAK has the ability to integrate with the Software Simulation Equipment (SSE) and the Mission Processing and Control System (MPCS) software which makes it a powerful tool within the MSL FSW development process. The MSL team must ensure that the rover accomplishes all stages of the mission successfully. Due to the natural complexity of this project there is a strong emphasis on testing, as failure is not an option. The entire mission could be jeopardized if something is overlooked.

  1. Fatigue evaluation of piping systems with limited vibration test data

    International Nuclear Information System (INIS)

    Huang, S.N.

    1990-11-01

    The safety-related piping in a nuclear power plant may be subjected to pump- or fluid-induced vibrations that, in general, affect only local areas of the piping systems. Pump- or fluid-induced vibrations typically are characterized by low levels of amplitudes and a high number of cycles over the lifetime of plant operation. Thus, the resulting fatigue damage to the piping systems could be an important safety concern. In general, tests and/or analyses are used to evaluate and qualify the piping systems. Test data, however, may be limited because of lack of instrumentation in critical piping locations and/or because of difficulty in obtaining data in inaccessible areas. This paper describes and summarizes a method to use limited pipe vibration test data, along with analytical harmonic response results from finite-element analyses, to assess the fatigue damage of nuclear power plant safety-related piping systems. 5 refs., 2 figs., 11 tabs

  2. 16 x 16 Vantage+ Fuel Assembly Flow Vibrational Testing

    International Nuclear Information System (INIS)

    Chambers, Martin; Kurincic, Bojan

    2014-01-01

    Nuklearna Elektrarna Krsko (NEK) has experienced leaking fuel after increasing the cycle duration to 18 months. The leaking fuel mechanism has predominantly been consistent over multiple cycles and is typically observed in highly irradiated Fuel Assemblies (FA) after around 4 years of continuous operation that were located at the core periphery (baffle). The cause of the leaking fuel is due to Grid-To-Rod-Fretting (GRTF) and occasional debris fretting. NEK utilises a 16x16 Vantage+ FA design with all Inconel structural mixing vane grids (8 in total), Zirlo thimbles, Integral Fuel Burnable Absorber (IFBA) rods with enriched ZrB2, enriched Annular Blanket, Debris Filter Bottom Nozzle (DFBN), Removable Top Nozzle (RTN) and Zirlo fuel cladding material with a high burnup capability of 60 GWD/MTU. Numerous design and operational changes are thought to have reduced the original 16x16 FA design margin to fretting resistance of either vibration or its wear work rate, such as significant power uprate (spring force loss, rod creep down...), operational cycle duration increase from 12 to 18 months (increasing residence time as well as lead FA and fuel rod burnup values), Reactor Coolant System flow increase (increased vibration), removal of Thimble Plugs (increased bypass flow, increased vibration) and Zirc-4 to Zirlo cladding change (decreasing wear work rate). The fuel rod to grid spring as well as dimple contact areas are relatively smaller than other FA designs that exhibit good in-reactor fretting performance. A FA design change project to address the small rod to dimple / spring contact area and utilise fuel cladding oxide coating is currently being pursued with the fuel supplier. The FA vibrational properties are very important to the in-reactor FA performance and reliability. The 16x16 Vantage+ vibrational testing was performed with a full size FA in the Fuel Assembly Compatibility Testing (FACTS) loop that is able to provide full flow rates at elevated temperature

  3. Asset Analysis and Operational Concepts for Separation Assurance Flight Testing at Dryden Flight Research Center

    Science.gov (United States)

    Costa, Guillermo J.; Arteaga, Ricardo A.

    2011-01-01

    A preliminary survey of existing separation assurance and collision avoidance advancements, technologies, and efforts has been conducted in order to develop a concept of operations for flight testing autonomous separation assurance at Dryden Flight Research Center. This effort was part of the Unmanned Aerial Systems in the National Airspace System project. The survey focused primarily on separation assurance projects validated through flight testing (including lessons learned), however current forays into the field were also examined. Comparisons between current Dryden flight and range assets were conducted using House of Quality matrices in order to allow project management to make determinations regarding asset utilization for future flight tests. This was conducted in order to establish a body of knowledge of the current collision avoidance landscape, and thus focus Dryden s efforts more effectively towards the providing of assets and test ranges for future flight testing within this research field.

  4. Active Blade Vibration Control Being Developed and Tested

    Science.gov (United States)

    Johnson, Dexter

    2003-01-01

    Gas turbine engines are currently being designed to have increased performance, lower weight and manufacturing costs, and higher reliability. Consequently, turbomachinery components, such as turbine and compressor blades, have designs that are susceptible to new vibration problems and eventual in-service failure due to high-cycle fatigue. To address this problem, researchers at the NASA Glenn Research Center are developing and testing innovative active blade vibration control concepts. Preliminary results of using an active blade vibration control system, involving a rotor supported by an active magnetic bearing in Glenn's Dynamic Spin Rig, indicate promising results (see the photograph). Active blade vibration control was achieved using feedback of blade strain gauge signals within the magnetic bearing control loop. The vibration amplitude was reduced substantially (see the graphs). Also, vibration amplitude amplification was demonstrated; this could be used to enhance structural mode identification, if desired. These results were for a nonrotating two-bladed disk. Tests for rotating blades are planned. Current and future active blade vibration control research is planned to use a fully magnetically suspended rotor and smart materials. For the fully magnetically suspended rotor work, three magnetic bearings (two radial and one axial) will be used as actuators instead of one magnetic bearing. This will allow additional degrees of freedom to be used for control. For the smart materials work, control effectors located on and off the blade will be considered. Piezoelectric materials will be considered for on-the-blade actuation, and actuator placement on a stator vane, or other nearby structure, will be investigated for off-the-blade actuation. Initial work will focus on determining the feasibility of these methods by performing basic analysis and simple experiments involving feedback control.

  5. Partnership Opportunities with AFRC for Wireless Systems Flight Testing

    Science.gov (United States)

    Hang, Richard

    2015-01-01

    The presentation will overview the flight test capabilities at NASA Armstrong Flight Research Center (AFRC), to open up partnership collaboration opportunities for Wireless Community to conduct flight testing of aerospace wireless technologies. Also, it will brief the current activities on wireless sensor system at AFRC through SBIR (Small Business Innovation Research) proposals, and it will show the current areas of interest on wireless technologies that AFRC would like collaborate with Wireless Community to further and testing.

  6. Small-scale fixed wing airplane software verification flight test

    Science.gov (United States)

    Miller, Natasha R.

    The increased demand for micro Unmanned Air Vehicles (UAV) driven by military requirements, commercial use, and academia is creating a need for the ability to quickly and accurately conduct low Reynolds Number aircraft design. There exist several open source software programs that are free or inexpensive that can be used for large scale aircraft design, but few software programs target the realm of low Reynolds Number flight. XFLR5 is an open source, free to download, software program that attempts to take into consideration viscous effects that occur at low Reynolds Number in airfoil design, 3D wing design, and 3D airplane design. An off the shelf, remote control airplane was used as a test bed to model in XFLR5 and then compared to flight test collected data. Flight test focused on the stability modes of the 3D plane, specifically the phugoid mode. Design and execution of the flight tests were accomplished for the RC airplane using methodology from full scale military airplane test procedures. Results from flight test were not conclusive in determining the accuracy of the XFLR5 software program. There were several sources of uncertainty that did not allow for a full analysis of the flight test results. An off the shelf drone autopilot was used as a data collection device for flight testing. The precision and accuracy of the autopilot is unknown. Potential future work should investigate flight test methods for small scale UAV flight.

  7. On Modal Parameter Estimates from Ambient Vibration Tests

    DEFF Research Database (Denmark)

    Agneni, A.; Brincker, Rune; Coppotelli, B.

    2004-01-01

    Modal parameter estimates from ambient vibration testing are turning into the preferred technique when one is interested in systems under actual loadings and operational conditions. Moreover, with this approach, expensive devices to excite the structure are not needed, since it can be adequately...

  8. CENTRIFUGAL VIBRATION TEST OF RC PILE FOUNDATION

    Science.gov (United States)

    Higuchi, Shunichi; Tsutsumiuchi, Takahiro; Otsuka, Rinna; Ito, Koji; Ejiri, Joji

    It is necessary that nonlinear responses of structures are clarified by soil-structure interaction analysis for the purpose of evaluating the seismic performances of underground structure or foundation structure. In this research, centrifuge shake table tests of reinforced concrete pile foundation installed in the liquefied ground were conducted. Then, finite element analyses for the tests were conducted to confirm an applicability of the analytical method by comparing the experimental results and analytical results.

  9. Research Problems Associated with Limiting the Applied Force in Vibration Tests and Conducting Base-Drive Modal Vibration Tests

    Science.gov (United States)

    Scharton, Terry D.

    1995-01-01

    The intent of this paper is to make a case for developing and conducting vibration tests which are both realistic and practical (a question of tailoring versus standards). Tests are essential for finding things overlooked in the analyses. The best test is often the most realistic test which can be conducted within the cost and budget constraints. Some standards are essential, but the author believes more in the individual's ingenuity to solve a specific problem than in the application of standards which reduce problems (and technology) to their lowest common denominator. Force limited vibration tests and base-drive modal tests are two examples of realistic, but practical testing approaches. Since both of these approaches are relatively new, a number of interesting research problems exist, and these are emphasized herein.

  10. Flight Test of an L(sub 1) Adaptive Controller on the NASA AirSTAR Flight Test Vehicle

    Science.gov (United States)

    Gregory, Irene M.; Xargay, Enric; Cao, Chengyu; Hovakimyan, Naira

    2010-01-01

    This paper presents results of a flight test of the L-1 adaptive control architecture designed to directly compensate for significant uncertain cross-coupling in nonlinear systems. The flight test was conducted on the subscale turbine powered Generic Transport Model that is an integral part of the Airborne Subscale Transport Aircraft Research system at the NASA Langley Research Center. The results presented are for piloted tasks performed during the flight test.

  11. An equipment test for grading lumber by transverse vibration technique

    Directory of Open Access Journals (Sweden)

    Marcelo Rodrigo Carreira

    2008-08-01

    Full Text Available Due to the great variability of its mechanical properties, the rational use of lumber for structural purposes is directly conditioned to its grading. There are several techniques available for grading structural lumber. The most relevant one is the transverse vibration technique which obtained reliable results in non-destructive evaluation of lumber. The purpose of this work is to present the bases for the mechanical grading of lumber and the results of the calibration test of the frst transverse vibration equipment developed in Brazil. In this research 30 beams of cupiúba (Goupia glabra with nominal dimensions of 5 cm X 10 cm X 300 cm, were used. The tests were accomplished at the Wood and Timber Structures Laboratory (LaMEM of the University of São Paulo (USP. The results showed a strong correlation between the elasticity modulus measured by the static bending test and the one obtained with the transverse vibration equipment, showing the high reliability of the vibration method for the grading of structural lumber. A determination coeffcient (R² of 0.896 was obtained with the Brazilian equipment, showing that it can be used in the grading of lumber.

  12. Flight Test Guide (Part 61 Revised): Instrument Pilot: Helicopter.

    Science.gov (United States)

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    The guide provides an outline of the skills required to pass the flight test for an Instrument Pilot Helicopter Rating under Part 61 (revised) of Federal Aviation Regulations. General procedures for flight tests are described and the following pilot operations outlined: maneuvering by reference to instruments, IFR navigation, instrument…

  13. Remotely Piloted Vehicles for Experimental Flight Control Testing

    Science.gov (United States)

    Motter, Mark A.; High, James W.

    2009-01-01

    A successful flight test and training campaign of the NASA Flying Controls Testbed was conducted at Naval Outlying Field, Webster Field, MD during 2008. Both the prop and jet-powered versions of the subscale, remotely piloted testbeds were used to test representative experimental flight controllers. These testbeds were developed by the Subsonic Fixed Wing Project s emphasis on new flight test techniques. The Subsonic Fixed Wing Project is under the Fundamental Aeronautics Program of NASA's Aeronautics Research Mission Directorate (ARMD). The purpose of these testbeds is to quickly and inexpensively evaluate advanced concepts and experimental flight controls, with applications to adaptive control, system identification, novel control effectors, correlation of subscale flight tests with wind tunnel results, and autonomous operations. Flight tests and operator training were conducted during four separate series of tests during April, May, June and August 2008. Experimental controllers were engaged and disengaged during fully autonomous flight in the designated test area. Flaps and landing gear were deployed by commands from the ground control station as unanticipated disturbances. The flight tests were performed NASA personnel with support from the Maritime Unmanned Development and Operations (MUDO) team of the Naval Air Warfare Center, Aircraft Division

  14. Vibration test report on the instrumented capsule for fuel irradiation test

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jeong Soo; Yoon, D. B.; Wu, J. S.; Oh, J. M.; Park, S. J.; Cho, M. S.; Kim, B. G.; Kang, Y. W

    2003-01-01

    The fluid-induced vibration level of instrumented capsule, which was manufactured for fuel irradiation test at the reactor core of HANARO, was investigated. For this purpose, the instrumented capsule was loaded at the OR site of the HANARO design verification test facility that could simulate identical flow condition as the HANARO core. Then, vibration signals of the instrumented capsule subjected to various flow conditions were measured by using vibration sensors. In time domain analysis, maximum amplitudes and RMS values of the measured acceleration and displacement signals were obtained. By using frequency domain analysis, frequency components of the fluid-induced vibration were analyzed. In addition, natural frequencies of the instrumented capsule were obtained by performing modal test. The frequency analysis results showed that the natural frequency components near 7.5Hz and 17.5Hz were dominant in the fluid-induced vibration signal. The maximum amplitude of the accelerations was measured as 12.04m/s{sup 2} that is within the allowable vibrational limit(18.99m/s{sup 2})of the reactor structure. Also, the maximum displacement amplitude was calculated as 0.191mm. Since these vibration levels are remarkably low, excessive vibration is not expected when the irradiation test of the instrumented capsule is performed at the HANARO core.

  15. Flight testing of a luminescent surface pressure sensor

    Science.gov (United States)

    Mclachlan, B. G.; Bell, J. H.; Espina, J.; Gallery, J.; Gouterman, M.; Demandante, C. G. N.; Bjarke, L.

    1992-01-01

    NASA ARC has conducted flight tests of a new type of aerodynamic pressure sensor based on a luminescent surface coating. Flights were conducted at the NASA ARC-Dryden Flight Research Facility. The luminescent pressure sensor is based on a surface coating which, when illuminated with ultraviolet light, emits visible light with an intensity dependent on the local air pressure on the surface. This technique makes it possible to obtain pressure data over the entire surface of an aircraft, as opposed to conventional instrumentation, which can only make measurements at pre-selected points. The objective of the flight tests was to evaluate the effectiveness and practicality of a luminescent pressure sensor in the actual flight environment. A luminescent pressure sensor was installed on a fin, the Flight Test Fixture (FTF), that is attached to the underside of an F-104 aircraft. The response of one particular surface coating was evaluated at low supersonic Mach numbers (M = 1.0-1.6) in order to provide an initial estimate of the sensor's capabilities. This memo describes the test approach, the techniques used, and the pressure sensor's behavior under flight conditions. A direct comparison between data provided by the luminescent pressure sensor and that produced by conventional pressure instrumentation shows that the luminescent sensor can provide quantitative data under flight conditions. However, the test results also show that the sensor has a number of limitations which must be addressed if this technique is to prove useful in the flight environment.

  16. Thermally Induced Vibrations of the Hubble Space Telescope's Solar Array 3 in a Test Simulated Space Environment

    Science.gov (United States)

    Early, Derrick A.; Haile, William B.; Turczyn, Mark T.; Griffin, Thomas J. (Technical Monitor)

    2001-01-01

    NASA Goddard Space Flight Center and the European Space Agency (ESA) conducted a disturbance verification test on a flight Solar Array 3 (SA3) for the Hubble Space Telescope using the ESA Large Space Simulator (LSS) in Noordwijk, the Netherlands. The LSS cyclically illuminated the SA3 to simulate orbital temperature changes in a vacuum environment. Data acquisition systems measured signals from force transducers and accelerometers resulting from thermally induced vibrations of the SAI The LSS with its seismic mass boundary provided an excellent background environment for this test. This paper discusses the analysis performed on the measured transient SA3 responses and provides a summary of the results.

  17. Cassini's Test Methodology for Flight Software Verification and Operations

    Science.gov (United States)

    Wang, Eric; Brown, Jay

    2007-01-01

    The Cassini spacecraft was launched on 15 October 1997 on a Titan IV-B launch vehicle. The spacecraft is comprised of various subsystems, including the Attitude and Articulation Control Subsystem (AACS). The AACS Flight Software (FSW) and its development has been an ongoing effort, from the design, development and finally operations. As planned, major modifications to certain FSW functions were designed, tested, verified and uploaded during the cruise phase of the mission. Each flight software upload involved extensive verification testing. A standardized FSW testing methodology was used to verify the integrity of the flight software. This paper summarizes the flight software testing methodology used for verifying FSW from pre-launch through the prime mission, with an emphasis on flight experience testing during the first 2.5 years of the prime mission (July 2004 through January 2007).

  18. Simulation to Flight Test for a UAV Controls Testbed

    Science.gov (United States)

    Motter, Mark A.; Logan, Michael J.; French, Michael L.; Guerreiro, Nelson M.

    2006-01-01

    The NASA Flying Controls Testbed (FLiC) is a relatively small and inexpensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches. The most recent version of the FLiC is configured with 16 independent aileron segments, supports the implementation of C-coded experimental controllers, and is capable of fully autonomous flight from takeoff roll to landing, including flight test maneuvers. The test vehicle is basically a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate (AATD) at Fort Eustis, Virginia and NASA Langley Research Center. Several vehicles have been constructed and collectively have flown over 600 successful test flights, including a fully autonomous demonstration at the Association of Unmanned Vehicle Systems International (AUVSI) UAV Demo 2005. Simulations based on wind tunnel data are being used to further develop advanced controllers for implementation and flight test.

  19. Satellite Vibration Testing: Angle optimisation method to Reduce Overtesting

    Science.gov (United States)

    Knight, Charly; Remedia, Marcello; Aglietti, Guglielmo S.; Richardson, Guy

    2018-06-01

    Spacecraft overtesting is a long running problem, and the main focus of most attempts to reduce it has been to adjust the base vibration input (i.e. notching). Instead this paper examines testing alternatives for secondary structures (equipment) coupled to the main structure (satellite) when they are tested separately. Even if the vibration source is applied along one of the orthogonal axes at the base of the coupled system (satellite plus equipment), the dynamics of the system and potentially the interface configuration mean the vibration at the interface may not occur all along one axis much less the corresponding orthogonal axis of the base excitation. This paper proposes an alternative testing methodology in which the testing of a piece of equipment occurs at an offset angle. This Angle Optimisation method may have multiple tests but each with an altered input direction allowing for the best match between all specified equipment system responses with coupled system tests. An optimisation process that compares the calculated equipment RMS values for a range of inputs with the maximum coupled system RMS values, and is used to find the optimal testing configuration for the given parameters. A case study was performed to find the best testing angles to match the acceleration responses of the centre of mass and sum of interface forces for all three axes, as well as the von Mises stress for an element by a fastening point. The angle optimisation method resulted in RMS values and PSD responses that were much closer to the coupled system when compared with traditional testing. The optimum testing configuration resulted in an overall average error significantly smaller than the traditional method. Crucially, this case study shows that the optimum test campaign could be a single equipment level test opposed to the traditional three orthogonal direction tests.

  20. Vibration test and endurance test for HANARO 36-element fuel assembly

    International Nuclear Information System (INIS)

    Ryu, Jeong Soo; Kim, Heon ll; Chung, Heung June

    1998-06-01

    Vibration test and endurance test for HANARO DU (depleted uranium) 36-element fuel assembly which was fabricated by KAERI were carried out based on the HANARO operation conditions. The endurance test of 22 days was added to the previous 18 days test. The vibration test was performed at various flow rates. Vibration frequency for the 36-element fuel assembly is between 11 to 14.5 Hz. And the maximum vibration displacement is less than 100 μm. From the endurance test result, it can be concluded that the appreciable fretting wear for the 36-element fuel assembly and the hexagonal flow tube was not observed. (author). 4 refs., 5 tabs., 29 figs

  1. Small UAS Test Area at NASA's Dryden Flight Research Center

    Science.gov (United States)

    Bauer, Jeffrey T.

    2008-01-01

    This viewgraph presentation reviews the areas that Dryden Flight Research Center has set up for testing small Unmanned Aerial Systems (UAS). It also reviews the requirements and process to use an area for UAS test.

  2. Flight Test Implementation of a Second Generation Intelligent Flight Control System

    Science.gov (United States)

    Williams-Hayes, Peggy S.

    2005-01-01

    The NASA F-15 Intelligent Flight Control System project team has developed a series of flight control concepts designed to demonstrate the benefits of a neural network-based adaptive controller. The objective of the team was to develop and flight-test control systems that use neural network technology, to optimize the performance of the aircraft under nominal conditions, and to stabilize the aircraft under failure conditions. Failure conditions include locked or failed control surfaces as well as unforeseen damage that might occur to the aircraft in flight. The Intelligent Flight Control System team is currently in the process of implementing a second generation control scheme, collectively known as Generation 2 or Gen 2, for flight testing on the NASA F-15 aircraft. This report describes the Gen 2 system as implemented by the team for flight test evaluation. Simulation results are shown which describe the experiment to be performed in flight and highlight the ways in which the Gen 2 system meets the defined objectives.

  3. Adaptive and robust active vibration control methodology and tests

    CERN Document Server

    Landau, Ioan Doré; Castellanos-Silva, Abraham; Constantinescu, Aurelian

    2017-01-01

    This book approaches the design of active vibration control systems from the perspective of today’s ideas of computer control. It formulates the various design problems encountered in the active management of vibration as control problems and searches for the most appropriate tools to solve them. The experimental validation of the solutions proposed on relevant tests benches is also addressed. To promote the widespread acceptance of these techniques, the presentation eliminates unnecessary theoretical developments (which can be found elsewhere) and focuses on algorithms and their use. The solutions proposed cannot be fully understood and creatively exploited without a clear understanding of the basic concepts and methods, so these are considered in depth. The focus is on enhancing motivations, algorithm presentation and experimental evaluation. MATLAB®routines, Simulink® diagrams and bench-test data are available for download and encourage easy assimilation of the experimental and exemplary material. Thre...

  4. Vibrations in water-gas heat exchangers. Design and tests

    International Nuclear Information System (INIS)

    Alexandre, M.; Allard, G.; Vangedhen, A.

    1981-01-01

    It is shown on an example how to make a complete list of the possible vibrations and how to use the data of tests and technical literature to predict damaging vibrations. The water-heavy gas tubular heat-exchanger in case is briefly described. The sources of mechanical excitations are a compressor and earthquake loadings. The various eigenmodes are described and it is shown that no resonance is possible with the compressor and that the effect of the earthquake is negligible. The excitation of the tubes by the gas flow is examined by means of Connors stability criterion; and there is no resonance with the Benard-von Karman vortices. The magnification of this latter excitation by acoustical waves is not to be feared. Satisfactory tests have been carried successively on tubes, on the casing, on the casing plus part of the tubes, on a complete prototype in workshop and in operation on site [fr

  5. Testing of Tools for Measurement Vibration in Car

    Directory of Open Access Journals (Sweden)

    Martin JURÁNEK

    2009-06-01

    Full Text Available This work is specialized on testing of several sensors for measurement vibration, that be applicable for measurement on vehicles also behind running. These sensors are connected to PC and universal mobile measuring system cRIO (National Instruments with analog I/O module for measurement vibration, that is described in diploma work: [JURÁNEK 2008]. This system has upped mechanical and heat imunity, small proportions and is therefore acceptable also measurement behind ride vehicles. It compose from two head parts. First is measuring part, composite from instruments cRIO. First part is controlled and monitored by PDA there is connected of wireless (second part hereof system. To system cRIO is possible connect sensors by four BNC connector or after small software change is possible add sensor to other analog modul cRIO. Here will be test several different types of accelerometers (USB sensor company Phidgets, MEMS sensor company Freescale, piezoresistiv and Delta Tron accelerometers company Brüel&Kjær. These sensors is attach to stiff board, board is attach to vibrator and excite by proper signal. Testing will realized with reference to using for measurement in cars. Results will be compared with professional signal analyser LabShop pulse from company Brüel&Kjær.

  6. Flight Test and Handling Qualities Analysis of a Longitudinal Flight Control System Using Multiobjective Techniques

    National Research Council Canada - National Science Library

    Anderson, John

    1998-01-01

    ...) and AFIT MXTOOLS toolboxes were used to produce the optimal, multiobjective designs. These designs were implemented for flight test on the Calspan VSS I Learjet, simulating the unstable longitudinal dynamics of an F-16 type aircraft...

  7. Atmospheric Measurements for Flight Test at NASAs Neil A. Armstrong Flight Research Center

    Science.gov (United States)

    Teets, Edward H.

    2016-01-01

    Information enclosed is to be shared with students of Atmospheric Sciences, Engineering and High School STEM programs. Information will show the relationship between atmospheric Sciences and aeronautical flight testing.

  8. Flight Test of L1 Adaptive Control Law: Offset Landings and Large Flight Envelope Modeling Work

    Science.gov (United States)

    Gregory, Irene M.; Xargay, Enric; Cao, Chengyu; Hovakimyan, Naira

    2011-01-01

    This paper presents new results of a flight test of the L1 adaptive control architecture designed to directly compensate for significant uncertain cross-coupling in nonlinear systems. The flight test was conducted on the subscale turbine powered Generic Transport Model that is an integral part of the Airborne Subscale Transport Aircraft Research system at the NASA Langley Research Center. The results presented include control law evaluation for piloted offset landing tasks as well as results in support of nonlinear aerodynamic modeling and real-time dynamic modeling of the departure-prone edges of the flight envelope.

  9. Development and evaluation of vibrating Kelly Ball Test (VKelly test) for the workability of concrete.

    Science.gov (United States)

    2015-03-01

    Due to the low workability of slipform concrete mixtures, the science of rheology is not strictly applicable for such concrete. However, : the concept of rheological behavior may still be considered useful. A novel workability test method (Vibrating ...

  10. Subsonic Glideback Rocket Demonstrator Flight Testing

    Science.gov (United States)

    DeTurris, Dianne J.; Foster, Trevor J.; Barthel, Paul E.; Macy, Daniel J.; Droney, Christopher K.; Talay, Theodore A. (Technical Monitor)

    2001-01-01

    For the past two years, Cal Poly's rocket program has been aggressively exploring the concept of remotely controlled, fixed wing, flyable rocket boosters. This program, embodied by a group of student engineers known as Cal Poly Space Systems, has successfully demonstrated the idea of a rocket design that incorporates a vertical launch pattern followed by a horizontal return flight and landing. Though the design is meant for supersonic flight, CPSS demonstrators are deployed at a subsonic speed. Many steps have been taken by the club that allowed the evolution of the StarBooster prototype to reach its current size: a ten-foot tall, one-foot diameter, composite material rocket. Progress is currently being made that involves multiple boosters along with a second stage, third rocket.

  11. Testing Microgravity Flight Hardware Concepts on the NASA KC-135

    Science.gov (United States)

    Motil, Susan M.; Harrivel, Angela R.; Zimmerli, Gregory A.

    2001-01-01

    This paper provides an overview of utilizing the NASA KC-135 Reduced Gravity Aircraft for the Foam Optics and Mechanics (FOAM) microgravity flight project. The FOAM science requirements are summarized, and the KC-135 test-rig used to test hardware concepts designed to meet the requirements are described. Preliminary results regarding foam dispensing, foam/surface slip tests, and dynamic light scattering data are discussed in support of the flight hardware development for the FOAM experiment.

  12. Random Vibration Testing of Advanced Wet Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander

    2015-01-01

    Advanced wet tantalum capacitors allow for improved performance of power supply systems along with substantial reduction of size and weight of the systems that is especially beneficial for space electronics. Due to launch-related stresses, acceptance testing of all space systems includes random vibration test (RVT). However, many types of advanced wet tantalum capacitors cannot pass consistently RVT at conditions specified in MIL-PRF-39006, which impedes their use in space projects. This requires a closer look at the existing requirements, modes and mechanisms of failures, specifics of test conditions, and acceptance criteria. In this work, different lots of advanced wet tantalum capacitors from four manufacturers have been tested at step stress random vibration conditions while their currents were monitored before, during, and after the testing. It has been shown that the robustness of the parts and their reliability are mostly due to effective self-healing processes and limited current spiking or minor scintillations caused by RVT do not increase the risk of failures during operation. A simple model for scintillations events has been used to simulate current spiking during RVT and optimize test conditions. The significance of scintillations and possible effects of gas generation have been discussed and test acceptance criteria for limited current spiking have been suggested.

  13. Orion Exploration Flight Test Reaction Control System Jet Interaction Heating Environment from Flight Data

    Science.gov (United States)

    White, Molly E.; Hyatt, Andrew J.

    2016-01-01

    The Orion Multi-Purpose Crew Vehicle (MPCV) Reaction Control System (RCS) is critical to guide the vehicle along the desired trajectory during re-­-entry. However, this system has a significant impact on the convective heating environment to the spacecraft. Heating augmentation from the jet interaction (JI) drives thermal protection system (TPS) material selection and thickness requirements for the spacecraft. This paper describes the heating environment from the RCS on the afterbody of the Orion MPCV during Orion's first flight test, Exploration Flight Test 1 (EFT-1). These jet plumes interact with the wake of the crew capsule and cause an increase in the convective heating environment. Not only is there widespread influence from the jet banks, there may also be very localized effects. The firing history during EFT-1 will be summarized to assess which jet bank interaction was measured during flight. Heating augmentation factors derived from the reconstructed flight data will be presented. Furthermore, flight instrumentation across the afterbody provides the highest spatial resolution of the region of influence of the individual jet banks of any spacecraft yet flown. This distribution of heating augmentation across the afterbody will be derived from the flight data. Additionally, trends with possible correlating parameters will be investigated to assist future designs and ground testing programs. Finally, the challenges of measuring JI, applying this data to future flights and lessons learned will be discussed.

  14. Flight Testing an Iced Business Jet for Flight Simulation Model Validation

    Science.gov (United States)

    Ratvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam; Cooper, Jon

    2007-01-01

    A flight test of a business jet aircraft with various ice accretions was performed to obtain data to validate flight simulation models developed through wind tunnel tests. Three types of ice accretions were tested: pre-activation roughness, runback shapes that form downstream of the thermal wing ice protection system, and a wing ice protection system failure shape. The high fidelity flight simulation models of this business jet aircraft were validated using a software tool called "Overdrive." Through comparisons of flight-extracted aerodynamic forces and moments to simulation-predicted forces and moments, the simulation models were successfully validated. Only minor adjustments in the simulation database were required to obtain adequate match, signifying the process used to develop the simulation models was successful. The simulation models were implemented in the NASA Ice Contamination Effects Flight Training Device (ICEFTD) to enable company pilots to evaluate flight characteristics of the simulation models. By and large, the pilots confirmed good similarities in the flight characteristics when compared to the real airplane. However, pilots noted pitch up tendencies at stall with the flaps extended that were not representative of the airplane and identified some differences in pilot forces. The elevator hinge moment model and implementation of the control forces on the ICEFTD were identified as a driver in the pitch ups and control force issues, and will be an area for future work.

  15. Vibrational Stability of SRF Accelerator Test Facility at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    McGee, M.W.; Volk, J.T.; /Fermilab

    2009-05-01

    Recently developed, the Superconducting Radio Frequency (SRF) Accelerator Test Facilities at Fermilab support the International Linear Collider (ILC), High Intensity Neutrino Source (HINS), a new high intensity injector (Project X) and other future machines. These facilities; Meson Detector Building (MDB) and New Muon Lab (NML) have very different foundations, structures, relative elevations with respect to grade level and surrounding soil composition. Also, there are differences in the operating equipment and their proximity to the primary machine. All the future machines have stringent operational stability requirements. The present study examines both near-field and ambient vibration in order to develop an understanding of the potential contribution of near-field sources (e.g. compressors, ultra-high and standard vacuum equipment, klystrons, modulators, utility fans and pumps) and distant noise sources to the overall system displacements. Facility vibration measurement results and methods of possible isolation from noise sources are presented and discussed.

  16. The Max Launch Abort System - Concept, Flight Test, and Evolution

    Science.gov (United States)

    Gilbert, Michael G.

    2014-01-01

    The NASA Engineering and Safety Center (NESC) is an independent engineering analysis and test organization providing support across the range of NASA programs. In 2007 NASA was developing the launch escape system for the Orion spacecraft that was evolved from the traditional tower-configuration escape systems used for the historic Mercury and Apollo spacecraft. The NESC was tasked, as a programmatic risk-reduction effort to develop and flight test an alternative to the Orion baseline escape system concept. This project became known as the Max Launch Abort System (MLAS), named in honor of Maxime Faget, the developer of the original Mercury escape system. Over the course of approximately two years the NESC performed conceptual and tradeoff analyses, designed and built full-scale flight test hardware, and conducted a flight test demonstration in July 2009. Since the flight test, the NESC has continued to further develop and refine the MLAS concept.

  17. Vibration tests of a 4-story concrete structure

    International Nuclear Information System (INIS)

    Chen, C.K.; Czarnecki, R.M.; Scholl, R.E.

    1976-01-01

    A series of forced vibration tests on a full-scale 4-story reinforced concrete test structure was performed to investigate its dynamic response before, after, and during the time it underwent structural damage. Nondestructive tests were conducted first, exciting four translational modes at force levels within the elastic limit, during which the structure suffered no structural damage. Next, a destructive test excited only the lowest translational mode at high-amplitude destructive levels, during which the structure exhibited inelastic response and suffered major structural damage. Post-destructive tests used force levels similar to the nondestructive tests. The work was in support of the program to develop methods for predicting building response to and damage from underground nuclear explosions

  18. Fused Reality for Enhanced Flight Test Capabilities, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In terms of relevancy to piloted evaluation, there remains no substitute for actual flight tests even when considering the fidelity and effectiveness of modern...

  19. Vibration phenomena in large scale pressure suppression tests

    International Nuclear Information System (INIS)

    Aust, E.; Boettcher, G.; Kolb, M.; Sattler, P.; Vollbrandt, J.

    1982-01-01

    Structure und fluid vibration phenomena (acceleration, strain; pressure, level) were observed during blow-down experiments simulating a LOCA in the GKSS full scale multivent pressure suppression test facility. The paper describes first the source related excitations during the two regimes of condensation oscillation and of chugging, and deals then with the response vibrations of the facility's wetwell. Modal analyses of the wetwell were run using excitation by hammer and by shaker in order to separate phenomena that are particular to the GKSS facility from more general ones, i.e. phenomena specific to the fluid related parameters of blowdown and to the geometry of the vent pipes only. The lowest periodicities at about 12 and 16 Hz stem from the vent acoustics. A frequency of about 36 to 38 Hz prominent during chugging seems to result from the lowest local models of two of the wetwell's walls when coupled by the wetwell pool. Further peaks found during blowdown in the spectra of signals at higher frequencies correspond to global vibration modes of the wetwell. (orig.)

  20. A Flight Control System Architecture for the NASA AirSTAR Flight Test Infrastructure

    Science.gov (United States)

    Murch, Austin M.

    2008-01-01

    A flight control system architecture for the NASA AirSTAR infrastructure has been designed to address the challenges associated with safe and efficient flight testing of research control laws in adverse flight conditions. The AirSTAR flight control system provides a flexible framework that enables NASA Aviation Safety Program research objectives, and includes the ability to rapidly integrate and test research control laws, emulate component or sensor failures, inject automated control surface perturbations, and provide a baseline control law for comparison to research control laws and to increase operational efficiency. The current baseline control law uses an angle of attack command augmentation system for the pitch axis and simple stability augmentation for the roll and yaw axes.

  1. New Cryogenic Optical Test Capability at Marshall Space Flight Center's Space Optics Manufacturing Technology Center

    Science.gov (United States)

    Kegley, Jeff; Burdine, Robert V. (Technical Monitor)

    2002-01-01

    A new cryogenic optical testing capability exists at Marshall Space Flight Center's Space Optics Manufacturing Technology Center (SOMTC). SOMTC has been performing optical wavefront testing at cryogenic temperatures since 1999 in the X-ray Cryogenic Test Facility's (XRCF's) large vacuum chamber. Recently the cryogenic optical testing capability has been extended to a smaller vacuum chamber. This smaller horizontal cylindrical vacuum chamber has been outfitted with a helium-cooled liner that can be connected to the facility's helium refrigeration system bringing the existing kilowatt of refrigeration capacity to bear on a 1 meter diameter x 2 meter long test envelope. Cryogenic environments to less than 20 Kelvin are now possible in only a few hours. SOMTC's existing instruments (the Instantaneous Phase-shifting Interferometer (IPI) from ADE Phase-Shift Technologies and the PhaseCam from 4D Vision Technologies) view the optic under test through a 150 mm clear aperture BK-7 window. Since activation and chamber characterization tests in September 2001, the new chamber has been used to perform a cryogenic (less than 30 Kelvin) optical test of a 22.5 cm diameter x 127 cm radius of curvature Si02 mirror, a cryogenic survival (less than 30 Kelvin) test of an adhesive, and a cryogenic cycle (less than 20 Kelvin) test of a ULE mirror. A vibration survey has also been performed on the test chamber. Chamber specifications and performance data, vibration environment data, and limited test results will be presented.

  2. Flight test of the X-29A at high angle of attack: Flight dynamics and controls

    Science.gov (United States)

    Bauer, Jeffrey E.; Clarke, Robert; Burken, John J.

    1995-01-01

    The NASA Dryden Flight Research Center has flight tested two X-29A aircraft at low and high angles of attack. The high-angle-of-attack tests evaluate the feasibility of integrated X-29A technologies. More specific objectives focus on evaluating the high-angle-of-attack flying qualities, defining multiaxis controllability limits, and determining the maximum pitch-pointing capability. A pilot-selectable gain system allows examination of tradeoffs in airplane stability and maneuverability. Basic fighter maneuvers provide qualitative evaluation. Bank angle captures permit qualitative data analysis. This paper discusses the design goals and approach for high-angle-of-attack control laws and provides results from the envelope expansion and handling qualities testing at intermediate angles of attack. Comparisons of the flight test results to the predictions are made where appropriate. The pitch rate command structure of the longitudinal control system is shown to be a valid design for high-angle-of-attack control laws. Flight test results show that wing rock amplitude was overpredicted and aileron and rudder effectiveness were underpredicted. Flight tests show the X-29A airplane to be a good aircraft up to 40 deg angle of attack.

  3. Design and flight testing of a nullable compressor face rake

    Science.gov (United States)

    Holzman, J. K.; Payne, G. A.

    1973-01-01

    A compressor face rake with an internal valve arrangement to permit nulling was designed, constructed, and tested in the laboratory and in flight at the NASA Flight Research Center. When actuated by the pilot in flight, the nullable rake allowed the transducer zero shifts to be determined and then subsequently removed during data reduction. Design details, the fabrication technique, the principle of operation, brief descriptions of associated digital zero-correction programs and the qualification tests, and test results are included. Sample flight data show that the zero shifts were large and unpredictable but could be measured in flight with the rake. The rake functioned reliably and as expected during 25 hours of operation under flight environmental conditions and temperatures from 230 K (-46 F) to greater than 430 K (314 F). The rake was nulled approximately 1000 times. The in-flight zero-shift measurement technique, as well as the rake design, was successful and should be useful in future applications, particularly where accurate measurements of both steady-state and dynamic pressures are required under adverse environmental conditions.

  4. Flight testing a propulsion-controlled aircraft emergency flight control system on an F-15 airplane

    Science.gov (United States)

    Burcham, F. W., Jr.; Burken, John; Maine, Trindel A.

    1994-01-01

    Flight tests of a propulsion-controlled aircraft (PCA) system on an F-15 airplane have been conducted at the NASA Dryden Flight Research Center. The airplane was flown with all flight control surfaces locked both in the manual throttles-only mode and in an augmented system mode. In the latter mode, pilot thumbwheel commands and aircraft feedback parameters were used to position the throttles. Flight evaluation results showed that the PCA system can be used to land an airplane that has suffered a major flight control system failure safely. The PCA system was used to recover the F-15 airplane from a severe upset condition, descend, and land. Pilots from NASA, U.S. Air Force, U.S. Navy, and McDonnell Douglas Aerospace evaluated the PCA system and were favorably impressed with its capability. Manual throttles-only approaches were unsuccessful. This paper describes the PCA system operation and testing. It also presents flight test results and pilot comments.

  5. Flight test guidelines for homebuilt and experimental aircraft

    CSIR Research Space (South Africa)

    White, WJ

    2013-04-01

    Full Text Available experience totalling approximately 7,000 flying hours on forty-five different variants of military aircraft, nearly all in the flight-test environment. He holds a Commercial Pilot’s Licence with a Class I test pilot rating. During his twenty-eight years... of military flight-testing, he was involved in the fixed wing fighter programmes and weapons development testing and amongst others, he was the project test pilot on the Cheetah C, the Mirage IIIRZ/Atar 09K50 engine integration and the Mirage F1 fitted...

  6. Modal vibration testing of the DVA-1 radio telescope

    Science.gov (United States)

    Byrnes, Peter W. G.; Lacy, Gordon

    2016-07-01

    The Dish Verification Antenna 1 (DVA-1) is a 15m aperture offset Gregorian radio telescope featuring a rim-supported single piece molded composite primary reflector on an altitude-azimuth pedestal mount. Vibration measurements of the DVA-1 telescope were conducted over three days in October 2014 by NSI Herzberg engineers. The purpose of these tests was to measure the first several natural frequencies of the DVA-1 telescope. This paper describes the experimental approach, in particular the step-release method, and summarizes some interesting results, including unexpectedly high damping of the first mode over a narrow range of zenith angles.

  7. Used fuel rail shock and vibration testing options analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Steven B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Best, Ralph E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Klymyshyn, Nicholas A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Maheras, Steven J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-09-25

    The objective of the rail shock and vibration tests is to complete the framework needed to quantify loads of fuel assembly components that are necessary to guide materials research and establish a technical basis for review organizations such as the U.S. Nuclear Regulatory Commission (NRC). A significant body of experimental and numerical modeling data exists to quantify loads and failure limits applicable to normal conditions of transport (NCT) rail transport, but the data are based on assumptions that can only be verified through experimental testing. The test options presented in this report represent possible paths for acquiring the data that are needed to confirm the assumptions of previous work, validate modeling methods that will be needed for evaluating transported fuel on a case-by-case basis, and inform material test campaigns on the anticipated range of fuel loading. The ultimate goal of this testing is to close all of the existing knowledge gaps related to the loading of used fuel under NCT conditions and inform the experiments and analysis program on specific endpoints for their research. The options include tests that would use an actual railcar, surrogate assemblies, and real or simulated rail transportation casks. The railcar carrying the cradle, cask, and surrogate fuel assembly payload would be moved in a train operating over rail track modified or selected to impart shock and vibration forces that occur during normal rail transportation. Computer modeling would be used to help design surrogates that may be needed for a rail cask, a cask’s internal basket, and a transport cradle. The objective of the design of surrogate components would be to provide a test platform that effectively simulates responses to rail shock and vibration loads that would be exhibited by state-of-the-art rail cask, basket, and/or cradle structures. The computer models would also be used to help determine the placement of instrumentation (accelerometers and strain gauges

  8. A Novel Vibration Mode Testing Method for Cylindrical Resonators Based on Microphones

    Directory of Open Access Journals (Sweden)

    Yongmeng Zhang

    2015-01-01

    Full Text Available Non-contact testing is an important method for the study of the vibrating characteristic of cylindrical resonators. For the vibratory cylinder gyroscope excited by piezo-electric electrodes, mode testing of the cylindrical resonator is difficult. In this paper, a novel vibration testing method for cylindrical resonators is proposed. This method uses a MEMS microphone, which has the characteristics of small size and accurate directivity, to measure the vibration of the cylindrical resonator. A testing system was established, then the system was used to measure the vibration mode of the resonator. The experimental results show that the orientation resolution of the node of the vibration mode is better than 0.1°. This method also has the advantages of low cost and easy operation. It can be used in vibration testing and provide accurate results, which is important for the study of the vibration mode and thermal stability of vibratory cylindrical gyroscopes.

  9. Software Considerations for Subscale Flight Testing of Experimental Control Laws

    Science.gov (United States)

    Murch, Austin M.; Cox, David E.; Cunningham, Kevin

    2009-01-01

    The NASA AirSTAR system has been designed to address the challenges associated with safe and efficient subscale flight testing of research control laws in adverse flight conditions. In this paper, software elements of this system are described, with an emphasis on components which allow for rapid prototyping and deployment of aircraft control laws. Through model-based design and automatic coding a common code-base is used for desktop analysis, piloted simulation and real-time flight control. The flight control system provides the ability to rapidly integrate and test multiple research control laws and to emulate component or sensor failures. Integrated integrity monitoring systems provide aircraft structural load protection, isolate the system from control algorithm failures, and monitor the health of telemetry streams. Finally, issues associated with software configuration management and code modularity are briefly discussed.

  10. Wind and Wake Sensing with UAV Formation Flight: System Development and Flight Testing

    Science.gov (United States)

    Larrabee, Trenton Jameson

    sensing data using UAVs in formation flight. This has been achieved and well documented before in manned aircraft but very little work has been done on UAV wake sensing especially during flight testing. This document describes the development and flight testing of small unmanned aerial system (UAS) for wind and wake sensing purpose including a Ground Control Station (GCS) and UAVs. This research can be stated in four major components. Firstly, formation flight was obtained by integrating a formation flight controller on the WVU Phastball Research UAV aircraft platform from the Flight Control Systems Laboratory (FCSL) at West Virginia University (WVU). Second, a new approach to wind estimation using an Unscented Kalman filter (UKF) is discussed along with results from flight data. Third, wake modeling within a simulator and wake sensing during formation flight is shown. Finally, experimental results are used to discuss the "sweet spot" for energy harvesting in formation flight, a novel approach to cooperative wind estimation, and gust suppression control for a follower aircraft in formation flight.

  11. HDR flood-water storage-tank modal vibration tests

    International Nuclear Information System (INIS)

    Gorman, V.W.; Thinnes, G.L.

    1983-01-01

    Modal vibration tests were conducted by EG and G Idaho on two vessels located at West Germany's Heissdampfreaktor (HDR) facility which is 25 kilometers east of Frankfurt. The tests were performed during May and June 1982 for the US Nuclear Regulatory Commission (NRC) as part of their cooperative effort with Kernforschungszentrum Karlsruhe (KfK) of West Germany. The primary purpose for performing this task was to determine modal properties (frequencies, mode shapes and associated damping ratios) in order to eventually provide guidelines for standards development by the NRC in modeling similar vessels. One of the vessels tested was a flood water storage tank (FWST) for empty, half full and full water conditions. The FWST was excited randomly with an electromagnetic shaker and by impulsive hammer blows. Excitation or input forces together with measured vessel responses were processed by a digital modal analyzer and stored on magnetic disks for subsequent evaluation

  12. BWR 9 X 9 Fuel Assembly Thermal-Hydraulic Tests (2): Hydraulic Vibration Test

    International Nuclear Information System (INIS)

    Yoshiaki Tsukuda; Katsuichiro Kamimura; Toshiitsu Hattori; Akira Tanabe; Noboru Saito; Masahiko Warashina; Yuji Nishino

    2002-01-01

    Nuclear Power Engineering Corporation (NUPEC) conducted thermal-hydraulic projects for verification of thermal-hydraulic design reliability for BWR high-burnup 8 x 8 and 9 x 9 fuel assemblies, entrusted by the Ministry of Economy, Trade and Industry (METI). As a part of the NUPEC thermal-hydraulic projects, hydraulic vibration tests using full-scale test assemblies simulating 9 x 9 fuel assemblies were carried out to evaluate BWR fuel integrity. The test data were applied to development of a new correlation for the estimation of fuel rod vibration amplitude. (authors)

  13. Space Shuttle Boundary Layer Transition Flight Experiment Ground Testing Overview

    Science.gov (United States)

    Berger, Karen T.; Anderson, Brian P.; Campbell, Charles H.

    2014-01-01

    In support of the Boundary Layer Transition (BLT) Flight Experiment (FE) Project in which a manufactured protuberance tile was installed on the port wing of Space Shuttle Orbiter Discovery for STS-119, STS- 128, STS-131 and STS-133 as well as Space Shuttle Orbiter Endeavour for STS-134, a significant ground test campaign was completed. The primary goals of the test campaign were to provide ground test data to support the planning and safety certification efforts required to fly the flight experiment as well as validation for the collected flight data. These test included Arcjet testing of the tile protuberance, aerothermal testing to determine the boundary layer transition behavior and resultant surface heating and planar laser induced fluorescence (PLIF) testing in order to gain a better understanding of the flow field characteristics associated with the flight experiment. This paper provides an overview of the BLT FE Project ground testing. High-level overviews of the facilities, models, test techniques and data are presented, along with a summary of the insights gained from each test.

  14. Field vibration test of principal equipment of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Shiraki, Kazuhiro; Fujita, Katsuhisa; Kajimura, Motohiko; Ikegami, Yasuhiko; Hanzawa, Katsumi; Sakai, Yoshiyuki; Kokubo, Eiji; Igarashi, Shigeru

    1984-09-01

    Japan is one of the most earthquake-stricken countries in the world, and demands for aseismic design have become severer recently. In a nuclear power plant in particular, consisting of a reactor vessel and other facilities dealing with a radioactive substance in some form or other, it is essential from the standpoint of safety to eliminate any possibility of radioactive hazards for the local public, and the employees at the plant as well, if these facilities are struck by an earthquake. This paper is related to the reactor vessel, reactor primary cooling equipment and piping system and important general piping as examples of important facilities of a nuclear power plant, and discusses vibration tests of an actual plant in the field from the standpoint of enhancing the aseismic safety of the Mitsubishi PWR nuclear power plant. Especially concerning vibration test technology, the effects in the evaluation of aseismic safety and its limits are studied to prove how it contributes to the enhancement of the reliability of aseismic design of nuclear power plants.

  15. The use of an automated flight test management system in the development of a rapid-prototyping flight research facility

    Science.gov (United States)

    Duke, Eugene L.; Hewett, Marle D.; Brumbaugh, Randal W.; Tartt, David M.; Antoniewicz, Robert F.; Agarwal, Arvind K.

    1988-01-01

    An automated flight test management system (ATMS) and its use to develop a rapid-prototyping flight research facility for artificial intelligence (AI) based flight systems concepts are described. The ATMS provides a flight test engineer with a set of tools that assist in flight planning and simulation. This system will be capable of controlling an aircraft during the flight test by performing closed-loop guidance functions, range management, and maneuver-quality monitoring. The rapid-prototyping flight research facility is being developed at the Dryden Flight Research Facility of the NASA Ames Research Center (Ames-Dryden) to provide early flight assessment of emerging AI technology. The facility is being developed as one element of the aircraft automation program which focuses on the qualification and validation of embedded real-time AI-based systems.

  16. Acoustic flight test of the Piper Lance

    Science.gov (United States)

    1986-12-01

    Research is being conducted to refine current noise regulation of propeller-driven small airplanes. Studies are examining the prospect of a substituting a takeoff procedure of equal stringency for the level flyover certification test presently requir...

  17. Artificial intelligence and expert systems in-flight software testing

    Science.gov (United States)

    Demasie, M. P.; Muratore, J. F.

    1991-01-01

    The authors discuss the introduction of advanced information systems technologies such as artificial intelligence, expert systems, and advanced human-computer interfaces directly into Space Shuttle software engineering. The reconfiguration automation project (RAP) was initiated to coordinate this move towards 1990s software technology. The idea behind RAP is to automate several phases of the flight software testing procedure and to introduce AI and ES into space shuttle flight software testing. In the first phase of RAP, conventional tools to automate regression testing have already been developed or acquired. There are currently three tools in use.

  18. Design and utilization of a Flight Test Engineering Database Management System at the NASA Dryden Flight Research Facility

    Science.gov (United States)

    Knighton, Donna L.

    1992-01-01

    A Flight Test Engineering Database Management System (FTE DBMS) was designed and implemented at the NASA Dryden Flight Research Facility. The X-29 Forward Swept Wing Advanced Technology Demonstrator flight research program was chosen for the initial system development and implementation. The FTE DBMS greatly assisted in planning and 'mass production' card preparation for an accelerated X-29 research program. Improved Test Plan tracking and maneuver management for a high flight-rate program were proven, and flight rates of up to three flights per day, two times per week were maintained.

  19. Structural damping results from vibration tests of straight piping sections

    International Nuclear Information System (INIS)

    Ware, A.G.; Thinnes, G.L.

    1984-01-01

    EG and G Idaho is assisting the USNRC and the Pressure Vessel Research Committee in supporting a final position on revised damping values for structural analyses of nuclear piping systems. As part of this program, a series of vibrational tests on 76-mm and 203-mm (3-in. amd 8-in.) Schedule 40 carbon steel piping was conducted to determine the changes in structural damping due to various parametric effects. The 10-m (33-ft) straight sections of piping were rigidly supported at the ends. Spring, rod, and constant force hangers, as well as a sway brace and snubbers were included as intermediate supports. Excitation was provided by low-force level hammer inpacts, a hydraulic shaker, and a 445-kN (50-ton) overhead crane. Data was recorded using acceleration, strain, and displacement time histories. This paper presents results from the testing showing the effect of stress level and type of supports on structural damping in piping

  20. Low Density Supersonic Decelerator Flight Dynamics Test-1 Flight Design and Targeting

    Science.gov (United States)

    Ivanov, Mark

    2015-01-01

    NASA's Low Density Supersonic Decelerator (LDSD) program was established to identify, develop, and eventually qualify to Test [i.e. Technology] Readiness Level (TRL) - 6 aerodynamic decelerators for eventual use on Mars. Through comprehensive Mars application studies, two distinct Supersonic Inflatable Aerodynamic Decelerator (SIAD) designs were chosen that afforded the optimum balance of benefit, cost, and development risk. In addition, a Supersonic Disk Sail (SSDS) parachute design was chosen that satisfied the same criteria. The final phase of the multi-tiered qualification process involves Earth Supersonic Flight Dynamics Tests (SFDTs) within environmental conditions similar to those that would be experienced during a Mars Entry, Descent, and Landing (EDL) mission. The first of these flight tests (i.e. SFDT-1) was completed on June 28, 2014 with two more tests scheduled for the summer of 2015 and 2016, respectively. The basic flight design for all the SFDT flights is for the SFDT test vehicle to be ferried to a float altitude of 120 kilo-feet by a 34 thousand cubic feet (Mcf) heavy lift helium balloon. Once float altitude is reached, the test vehicle is released from the balloon, spun-up for stability, and accelerated to supersonic speeds using a Star48 solid rocket motor. After burnout of the Star48 motor the vehicle decelerates to pre-flight selected test conditions for the deployment of the SIAD system. After further deceleration with the SIAD deployed, the SSDS parachute is then deployed stressing the performance of the parachute in the wake of the SIAD augmented blunt body. The test vehicle/SIAD/parachute system then descends to splashdown in the Pacific Ocean for eventual recovery. This paper will discuss the development of both the test vehicle and the trajectory sequence including design trade-offs resulting from the interaction of both engineering efforts. In addition, the SFDT-1 nominal trajectory design and associated sensitivities will be discussed

  1. UAV Research, Operations, and Flight Test at the NASA Dryden Flight Research Center

    Science.gov (United States)

    Cosentino, Gary B.

    2009-01-01

    This slide presentation reviews some of the projects that have extended NASA Dryden's capabilities in designing, testing, and using Unmanned Aerial Vehicles (UAV's). Some of the UAV's have been for Science and experimental applications, some have been for flight research and demonstration purposes, and some have been small UAV's for other customers.

  2. Helicopter Acoustic Flight Test with Altitude Variation and Maneuvers

    Science.gov (United States)

    Watts, Michael E.; Greenwood, Eric; Sim, Ben; Stephenson, James; Smith, Charles D.

    2016-01-01

    A cooperative flight test campaign between NASA and the U.S. Army was performed from September 2014 to February 2015. The purposes of the testing were to: investigate the effects of altitude variation on noise generation, investigate the effects of gross weight variation on noise generation, establish the statistical variability in acoustic flight testing of helicopters, and characterize the effects of transient maneuvers on radiated noise for a medium-lift utility helicopter. This test was performed at three test sites (0, 4000, and 7000 feet above mean sea level) with two aircraft (AS350 SD1 and EH-60L) tested at each site. This report provides an overview of the test, documents the data acquired and describes the formats of the stored data.

  3. Tube vibration in industrial size test heat exchanger

    International Nuclear Information System (INIS)

    Halle, H.; Wambsganss, M.W.

    1980-03-01

    Tube vibration data from tests of a specially built and instrumented, industrial-type, shell-and-tube heat exchanger are reported. The heat exchanger is nominally 0.6 m (2 ft) in dia and 3.7 m (12 ft) long. Both full tube and no-tubes-in-window bundles were tested for inlet/outlet nozzles of different sizes and with the tubes supported by seven, equally-spaced, single-segmental baffles. Prior to water flow testing, natural frequencies and damping of representative tubes were measured in air and water. Flow testing was accomplished by increasing the flow rates in stepwise fashion and also by sweeping through a selected range of flow rates. The primary variables measured and reported are tube accelerations and/or displacements and pressure drop through the bundle. Tests of the full tube bundle configuration revealed tube rattling to occur at intermediate flow rates, and fluidelastic instability, with resultant tube impacting, to occur when the flow rate exceeded a threshold level; principally, the four-span tubes were involved in the regions immediately adjacent to the baffle cut. For the range of flow rates tested, fluidelastic instability was not achieved in the no-tubes-in-window bundle; in this configuration the tubes are supported by all seven baffles and are, therefore, stiffer

  4. High Frequency Vibration Based Fatigue Testing of Developmental Alloys

    Science.gov (United States)

    Holycross, Casey M.; Srinivasan, Raghavan; George, Tommy J.; Tamirisakandala, Seshacharyulu; Russ, Stephan M.

    Many fatigue test methods have been previously developed to rapidly evaluate fatigue behavior. This increased test speed can come at some expense, since these methods may require non-standard specimen geometry or increased facility and equipment capability. One such method, developed by George et al, involves a base-excited plate specimen driven into a high frequency bending resonant mode. This resonant mode is of sufficient frequency (typically 1200 to 1700 Hertz) to accumulate 107 cycles in a few hours. One of the main limitations of this test method is that fatigue cracking is almost certainly guaranteed to be surface initiated at regions of high stress. This brings into question the validity of the fatigue test results, as compared to more traditional uniaxial, smooth-bar testing, since high stresses are subjecting only a small volume to fatigue damage. This limitation also brings into question the suitability of this method to screen developmental alloys, should their initiation life be governed by subsurface flaws. However, if applicable, the rapid generation of fatigue data using this method would facilitate faster design iterations, identifying more quickly, material and manufacturing process deficiencies. The developmental alloy used in this study was a powder metallurgy boron-modified Ti-6Al-4V, a new alloy currently being considered for gas turbine engine fan blades. Plate specimens were subjected to fully reversed bending fatigue. Results are compared with existing data from commercially available Ti-6Al-4V using both vibration based and more traditional fatigue test methods.

  5. Field Test Data for Detecting Vibrations of a Building Using High-Speed Video Cameras

    Science.gov (United States)

    2017-10-01

    ARL-TR-8185 ● OCT 2017 US Army Research Laboratory Field Test Data for Detecting Vibrations of a Building Using High-Speed Video...Field Test Data for Detecting Vibrations of a Building Using High-Speed Video Cameras by Caitlin P Conn and Geoffrey H Goldman Sensors and...June 2016 – October 2017 4. TITLE AND SUBTITLE Field Test Data for Detecting Vibrations of a Building Using High-Speed Video Cameras 5a. CONTRACT

  6. Forced vibration tests of a model foundation on rock ground

    International Nuclear Information System (INIS)

    Kisaki, N.; Siota, M.; Yamada, M.; Ikeda, A.; Tsuchiya, H.; Kitazawa, K.; Kuwabara, Y.; Ogiwara, Y.

    1983-01-01

    The response of very stiff structures, such as nuclear reactor buildings, to earthquake ground motion is significantly affected by radiation damping due to the soil-structure interaction. The radiation damping can be computed by vibration admittance theory or dynamical ground compliance theory. In order to apply the values derived from these theories to the practical problems, comparative studies between theoretical results and experimental results concerning the soil-structure interaction, especially if the ground is rock, are urgently needed. However, experimental results for rock are less easily obtained than theoretical ones. The purpose of this paper is to describe the harmonic excitation tests of a model foundation on rock and to describe the results of comparative studies. (orig./HP)

  7. Armstrong Flight Research Center Flight Test Capabilities and Opportunities for the Applications of Wireless Data Acquisition Systems

    Science.gov (United States)

    Hang, Richard

    2015-01-01

    The presentation will overview NASA Armstrong Flight Research Centers flight test capabilities, which can provide various means for flight testing of passive and active wireless sensor systems, also, it will address the needs of the wireless data acquisition solutions for the centers flight instrumentation issues such as additional weight caused by added instrumentation wire bundles, connectors, wire cables routing, moving components, etc., that the Passive Wireless Sensor Technology Workshop may help. The presentation shows the constraints and requirements that the wireless sensor systems will face in the flight test applications.

  8. NPS Solar Cell Array Tester Cubesat Flight Testing and Integration

    Science.gov (United States)

    2014-09-01

    with current (I). P V I      (2.1) This is significant because the battery discharge test will not lineup perfectly with Figure 12...accordance with the charging procedures [13]. 3. NPS-SCAT Power Budget A power budget analysis was performed to determine if the NPS-SCAT is self...using procedures developed by Marissa Brummitt, and with the assistance of Adam Hill, NPS-SCAT Program Manager. 1. ELaNa IV Random Vibration Levels

  9. Flight test of a resident backup software system

    Science.gov (United States)

    Deets, Dwain A.; Lock, Wilton P.; Megna, Vincent A.

    1987-01-01

    A new fault-tolerant system software concept employing the primary digital computers as host for the backup software portion has been implemented and flight tested in the F-8 digital fly-by-wire airplane. The system was implemented in such a way that essentially no transients occurred in transferring from primary to backup software. This was accomplished without a significant increase in the complexity of the backup software. The primary digital system was frame synchronized, which provided several advantages in implementing the resident backup software system. Since the time of the flight tests, two other flight vehicle programs have made a commitment to incorporate resident backup software similar in nature to the system described here.

  10. Design of a Maglev Vibration Test Platform for the Research of Maglev Vehicle-girder Coupled Vibration Problem

    Directory of Open Access Journals (Sweden)

    Zhou Danfeng

    2017-01-01

    Full Text Available The maglev vehicle-girder coupled vibration problem has been encountered in many maglev test or commercial lines, which significantly degrade the performance of the maglev train. In previous research on the principle of the coupled vibration problem, it has been discovered that the fundamental model of the maglev girder can be simplified as a series of mass-spring resonators of different but related resonance frequencies, and that the stability of the vehicle-girder coupled system can be investigated by separately examining the stability of each mass-spring resonator – electromagnet coupled system. Based on this conclusion, a maglev test platform, which includes a single electromagnetic suspension control system, is built for experimental study of the coupled vibration problem. The guideway of the test platform is supported by a number of springs so as to change its flexibility. The mass of the guideway can also be changed by adjusting extra weights attached to it. By changing the flexibility and mass of the guideway, the rules of the maglev vehicle-girder coupled vibration problem are to be examined through experiments, and related theory on the vehicle-girder self-excited vibration proposed in previous research is also testified.

  11. Flight Test Results for the F-16XL With a Digital Flight Control System

    Science.gov (United States)

    Stachowiak, Susan J.; Bosworth, John T.

    2004-01-01

    In the early 1980s, two F-16 airplanes were modified to extend the fuselage length and incorporate a large area delta wing planform. These two airplanes, designated the F-16XL, were designed by the General Dynamics Corporation (now Lockheed Martin Tactical Aircraft Systems) (Fort Worth, Texas) and were prototypes for a derivative fighter evaluation program conducted by the United States Air Force. Although the concept was never put into production, the F-16XL prototypes provided a unique planform for testing concepts in support of future high-speed supersonic transport aircraft. To extend the capabilities of this testbed vehicle the F-16XL ship 1 aircraft was upgraded with a digital flight control system. The added flexibility of a digital flight control system increases the versatility of this airplane as a testbed for aerodynamic research and investigation of advanced technologies. This report presents the handling qualities flight test results covering the envelope expansion of the F-16XL with the digital flight control system.

  12. Aerodynamic Reconstruction Applied to Parachute Test Vehicle Flight Data Analysis

    Science.gov (United States)

    Cassady, Leonard D.; Ray, Eric S.; Truong, Tuan H.

    2013-01-01

    The aerodynamics, both static and dynamic, of a test vehicle are critical to determining the performance of the parachute cluster in a drop test and for conducting a successful test. The Capsule Parachute Assembly System (CPAS) project is conducting tests of NASA's Orion Multi-Purpose Crew Vehicle (MPCV) parachutes at the Army Yuma Proving Ground utilizing the Parachute Test Vehicle (PTV). The PTV shape is based on the MPCV, but the height has been reduced in order to fit within the C-17 aircraft for extraction. Therefore, the aerodynamics of the PTV are similar, but not the same as, the MPCV. A small series of wind tunnel tests and computational fluid dynamics cases were run to modify the MPCV aerodynamic database for the PTV, but aerodynamic reconstruction of the flights has proven an effective source for further improvements to the database. The acceleration and rotational rates measured during free flight, before parachute inflation but during deployment, were used to con rm vehicle static aerodynamics. A multibody simulation is utilized to reconstruct the parachute portions of the flight. Aerodynamic or parachute parameters are adjusted in the simulation until the prediction reasonably matches the flight trajectory. Knowledge of the static aerodynamics is critical in the CPAS project because the parachute riser load measurements are scaled based on forebody drag. PTV dynamic damping is critical because the vehicle has no reaction control system to maintain attitude - the vehicle dynamics must be understood and modeled correctly before flight. It will be shown here that aerodynamic reconstruction has successfully contributed to the CPAS project.

  13. Design of a quadrotor flight test stand for system identification

    CSIR Research Space (South Africa)

    Beharie, MM

    2015-01-01

    Full Text Available This paper presents the design, development and construction of a flight test stand for a quadrotor UAV. As opposed to alternate forms of UAV, the power plant in the case of the quadrotor serves a dual purpose of control and propulsion. Since...

  14. HIFiRE-5 Flight Test Preliminary Results (Postprint)

    Science.gov (United States)

    2013-11-01

    CFD . 15. SUBJECT TERMS Boundary layer transition, hypersonic , flight test 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT: SAR 18...consistent with prior CFD 33,34 and wind tunnel measurements 28,29 at hypersonic conditions that indicated that the centerline is more unstable... Hypersonic Sciences Branch High Speed Systems Division NOVEMBER 2013 Approved for public release; distribution unlimited

  15. IN-SITU TEST OF PRESSURE PIPELINE VIBRATION BASED ON DATA ACQUISITION AND SIGNAL PROCESSING

    OpenAIRE

    Hou, Huimin; Xu, Cundong; Liu, Hui; Wang, Rongrong; Jie, Junkun; Ding, Lianying

    2015-01-01

    Pipeline vibration of high frequency and large amplitude is an important factor that impacts the safe operation of pumping station and the efficiency of the pumps. Through conducting the vibration in-situ test of pipeline system in the pumping station, we can objectively analyze the mechanism of pipeline vibration and evaluate the stability of pipeline operation. By using DASP (data acquisition & signal processing) in the in-situ test on the 2# pipeline of the third pumping station in the gen...

  16. Maneuver Acoustic Flight Test of the Bell 430 Helicopter

    Science.gov (United States)

    Watts, Michael E.; Snider, Royce; Greenwood, Eric; Baden, Joel

    2012-01-01

    A cooperative flight test by NASA, Bell Helicopter and the U.S. Army to characterize the steady state acoustics and measure the maneuver noise of a Bell Helicopter 430 aircraft was accomplished. The test occurred during June/July, 2011 at Eglin Air Force Base, Florida. This test gathered a total of 410 data points over 10 test days and compiled an extensive data base of dynamic maneuver measurements. Three microphone configurations with up to 31 microphones in each configuration were used to acquire acoustic data. Aircraft data included DGPS, aircraft state and rotor state information. This paper provides an overview of the test.

  17. Vibration damage testing of thermal barrier fibrous blanket insulation

    International Nuclear Information System (INIS)

    Black, W.E.; Betts, W.S.

    1984-01-01

    GA Technologies is engaged in a long-term, multiphase program to determine the vibration characteristics of thermal barrier components leading to qualification of assemblies for High Temperature Gas-Cooled Reactor (HTGR) service. The phase of primary emphasis described herein is the third in a series of acoustic tests and uses as background the more elemental tests preceding it. Two sizes of thermal barrier coverplates with one fibrous blanket insulation type were tested in an acoustic environment at sound pressure levels up to 160 dB. Three tests were conducted using sinusoidal and random noise for up to 200 h duration at room temperature. Frequent inspections were made to determine the progression of degradation using definition of stages from a prior test program. Initially the insulation surface adjacent to the metallic seal sheets (noise side) assumed a chafed or polished appearance. This was followed by flattening of the as-received pillowed surface. This stage was followed by a depression being formed in the vicinity of the free edge of the coverplate. Next, loose powder from within the blanket and from fiber erosion accumulated in the depression. Prior experience showed that the next stage of deterioration exhibited a consolidation of the powder to form a local crust. In this test series, this last stage generally failed to materialize. Instead, surface holes generated by solid ceramic particulates (commonly referred to as 'shot') constituted the stage following powdering. With the exception of some manufacturing-induced anomalies, the final stage, namely, gross fiber breakup, did not occur. It is this last stage that must be prevented for the thermal barrier to maintain its integrity. (orig./GL)

  18. Topographic analysis of the skull vibration-induced nystagmus test with piezoelectric accelerometers and force sensors.

    Science.gov (United States)

    Dumas, Georges; Lion, Alexis; Perrin, Philippe; Ouedraogo, Evariste; Schmerber, Sébastien

    2016-03-23

    Vibration-induced nystagmus is elicited by skull or posterior cervical muscle stimulations in patients with vestibular diseases. Skull vibrations delivered by the skull vibration-induced nystagmus test are known to stimulate the inner ear structures directly. This study aimed to measure the vibration transfer at different cranium locations and posterior cervical regions to contribute toward stimulus topographic optimization (experiment 1) and to determine the force applied on the skull with a hand-held vibrator to study the test reproducibility and provide recommendations for good clinical practices (experiment 2). In experiment 1, a 100 Hz hand-held vibrator was applied on the skull (vertex, mastoids) and posterior cervical muscles in 11 healthy participants. Vibration transfer was measured by piezoelectric sensors. In experiment 2, the vibrator was applied 30 times by two experimenters with dominant and nondominant hands on a mannequin equipped to measure the force. Experiment 1 showed that after unilateral mastoid vibratory stimulation, the signal transfer was higher when recorded on the contralateral mastoid than on the vertex or posterior cervical muscles (Pskull vibration-induced nystagmus test in patients with unilateral vestibular lesions and enables a stronger stimulation of the healthy side. In clinical practice, the vibrator should be placed on the mastoid and should be held by the clinician's dominant hand.

  19. Ultrasonic testing using time of flight diffraction technique (TOFD)

    International Nuclear Information System (INIS)

    Khurram Shahzad; Ahmad Mirza Safeer Ahmad; Muhammad Asif Khan

    2009-04-01

    This paper describes the ultrasonic testing using Time Flight Diffraction (TOFD) Technique for welded samples having different types and sizes of defects. TOFD is a computerized ultrasonic system, able to scan, store and evaluate indications in terms of location, through thickness and length in a more easy and convenient. Time of Flight Diffraction Technique (TOFD) is more fast and easy technique for ultrasonic testing as we can examine a weld i a single scan along the length of the weld with two probes known as D-scan. It shows the image of the complete weld with the defect information. The examinations were performed on carbon steel samples used for ultrasonic testing using 70 degree probes. The images for different type of defects were obtained. (author)

  20. Deployment Testing of the De-Orbit Sail Flight Hardware

    OpenAIRE

    Hillebrandt, Martin; Meyer, Sebastian; Zander, Martin; Hühne, Christian

    2015-01-01

    The paper describes the results of the deployment testing of the De-Orbit Sail flight hardware, a drag sail for de-orbiting applications, performed by DLR. It addresses in particular the deployment tests of the fullscale sail subsystem and deployment force tests performed on the boom deployment module. For the fullscale sail testing a gravity compensation device is used which is described in detail. It allows observations of the in-plane interaction of the booms with the sail membrane and the...

  1. Navigation and flight director guidance for the NASA/FAA helicopter MLS curved approach flight test program

    Science.gov (United States)

    Phatak, A. V.; Lee, M. G.

    1985-01-01

    The navigation and flight director guidance systems implemented in the NASA/FAA helicopter microwave landing system (MLS) curved approach flight test program is described. Flight test were conducted at the U.S. Navy's Crows Landing facility, using the NASA Ames UH-lH helicopter equipped with the V/STOLAND avionics system. The purpose of these tests was to investigate the feasibility of flying complex, curved and descending approaches to a landing using MLS flight director guidance. A description of the navigation aids used, the avionics system, cockpit instrumentation and on-board navigation equipment used for the flight test is provided. Three generic reference flight paths were developed and flown during the test. They were as follows: U-Turn, S-turn and Straight-In flight profiles. These profiles and their geometries are described in detail. A 3-cue flight director was implemented on the helicopter. A description of the formulation and implementation of the flight director laws is also presented. Performance data and analysis is presented for one pilot conducting the flight director approaches.

  2. Development and Flight Testing of a Neural Network Based Flight Control System on the NF-15B Aircraft

    Science.gov (United States)

    Bomben, Craig R.; Smolka, James W.; Bosworth, John T.; Silliams-Hayes, Peggy S.; Burken, John J.; Larson, Richard R.; Buschbacher, Mark J.; Maliska, Heather A.

    2006-01-01

    The Intelligent Flight Control System (IFCS) project at the NASA Dryden Flight Research Center, Edwards AFB, CA, has been investigating the use of neural network based adaptive control on a unique NF-15B test aircraft. The IFCS neural network is a software processor that stores measured aircraft response information to dynamically alter flight control gains. In 2006, the neural network was engaged and allowed to learn in real time to dynamically alter the aircraft handling qualities characteristics in the presence of actual aerodynamic failure conditions injected into the aircraft through the flight control system. The use of neural network and similar adaptive technologies in the design of highly fault and damage tolerant flight control systems shows promise in making future aircraft far more survivable than current technology allows. This paper will present the results of the IFCS flight test program conducted at the NASA Dryden Flight Research Center in 2006, with emphasis on challenges encountered and lessons learned.

  3. Mars Science Laboratory Flight Software Boot Robustness Testing Project Report

    Science.gov (United States)

    Roth, Brian

    2011-01-01

    On the surface of Mars, the Mars Science Laboratory will boot up its flight computers every morning, having charged the batteries through the night. This boot process is complicated, critical, and affected by numerous hardware states that can be difficult to test. The hardware test beds do not facilitate testing a long duration of back-to-back unmanned automated tests, and although the software simulation has provided the necessary functionality and fidelity for this boot testing, there has not been support for the full flexibility necessary for this task. Therefore to perform this testing a framework has been build around the software simulation that supports running automated tests loading a variety of starting configurations for software and hardware states. This implementation has been tested against the nominal cases to validate the methodology, and support for configuring off-nominal cases is ongoing. The implication of this testing is that the introduction of input configurations that have yet proved difficult to test may reveal boot scenarios worth higher fidelity investigation, and in other cases increase confidence in the robustness of the flight software boot process.

  4. Model Based Analysis and Test Generation for Flight Software

    Science.gov (United States)

    Pasareanu, Corina S.; Schumann, Johann M.; Mehlitz, Peter C.; Lowry, Mike R.; Karsai, Gabor; Nine, Harmon; Neema, Sandeep

    2009-01-01

    We describe a framework for model-based analysis and test case generation in the context of a heterogeneous model-based development paradigm that uses and combines Math- Works and UML 2.0 models and the associated code generation tools. This paradigm poses novel challenges to analysis and test case generation that, to the best of our knowledge, have not been addressed before. The framework is based on a common intermediate representation for different modeling formalisms and leverages and extends model checking and symbolic execution tools for model analysis and test case generation, respectively. We discuss the application of our framework to software models for a NASA flight mission.

  5. Integrated Vibration and Acceleration Testing to Reduce Payload Mass, Cost and Mission Risk, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a capability to provide integrated acceleration, vibration, and shock testing using a state-of-the-art centrifuge, allowing for the test of...

  6. Full-scale flight tests of aircraft morphing structures using SMA actuators

    Science.gov (United States)

    Mabe, James H.; Calkins, Frederick T.; Ruggeri, Robert T.

    2007-04-01

    In August of 2005 The Boeing Company conducted a full-scale flight test utilizing Shape Memory Alloy (SMA) actuators to morph an engine's fan exhaust to correlate exhaust geometry with jet noise reduction. The test was conducted on a 777-300ER with GE-115B engines. The presence of chevrons, serrated aerodynamic surfaces mounted at the trailing edge of the thrust reverser, have been shown to greatly reduce jet noise by encouraging advantageous mixing of the free, and fan streams. The morphing, or Variable Geometry Chevrons (VGC), utilized compact, light weight, and robust SMA actuators to morph the chevron shape to optimize the noise reduction or meet acoustic test objectives. The VGC system was designed for two modes of operation. The entirely autonomous operation utilized changes in the ambient temperature from take-off to cruise to activate the chevron shape change. It required no internal heaters, wiring, control system, or sensing. By design this provided one tip immersion at the warmer take-off temperatures to reduce community noise and another during the cooler cruise state for more efficient engine operation, i.e. reduced specific fuel consumption. For the flight tests a powered mode was added where internal heaters were used to individually control the VGC temperatures. This enabled us to vary the immersions and test a variety of chevron configurations. The flight test demonstrated the value of SMA actuators to solve a real world aerospace problem, validated that the technology could be safely integrated into the airplane's structure and flight system, and represented a large step forward in the realization of SMA actuators for production applications. In this paper the authors describe the development of the actuator system, the steps required to integrate the morphing structure into the thrust reverser, and the analysis and testing that was required to gain approval for flight. Issues related to material strength, thermal environment, vibration

  7. Pre-Flight Tests with Astronauts, Flight and Ground Hardware, to Assure On-Orbit Success

    Science.gov (United States)

    Haddad Michael E.

    2010-01-01

    On-Orbit Constraints Test (OOCT's) refers to mating flight hardware together on the ground before they will be mated on-orbit or on the Lunar surface. The concept seems simple but it can be difficult to perform operations like this on the ground when the flight hardware is being designed to be mated on-orbit in a zero-g/vacuum environment of space or low-g/vacuum environment on the Lunar/Mars Surface. Also some of the items are manufactured years apart so how are mating tasks performed on these components if one piece is on-orbit/on Lunar/Mars surface before its mating piece is planned to be built. Both the Internal Vehicular Activity (IVA) and Extra-Vehicular Activity (EVA) OOCT's performed at Kennedy Space Center will be presented in this paper. Details include how OOCT's should mimic on-orbit/Lunar/Mars surface operational scenarios, a series of photographs will be shown that were taken during OOCT's performed on International Space Station (ISS) flight elements, lessons learned as a result of the OOCT's will be presented and the paper will conclude with possible applications to Moon and Mars Surface operations planned for the Constellation Program.

  8. Development and Flight Test of an Augmented Thrust-Only Flight Control System on an MD-11 Transport Airplane

    Science.gov (United States)

    Burcham, Frank W., Jr.; Maine, Trindel A.; Burken, John J.; Pappas, Drew

    1996-01-01

    An emergency flight control system using only engine thrust, called Propulsion-Controlled Aircraft (PCA), has been developed and flight tested on an MD-11 airplane. In this thrust-only control system, pilot flight path and track commands and aircraft feedback parameters are used to control the throttles. The PCA system was installed on the MD-11 airplane using software modifications to existing computers. Flight test results show that the PCA system can be used to fly to an airport and safely land a transport airplane with an inoperative flight control system. In up-and-away operation, the PCA system served as an acceptable autopilot capable of extended flight over a range of speeds and altitudes. The PCA approaches, go-arounds, and three landings without the use of any non-nal flight controls have been demonstrated, including instrument landing system-coupled hands-off landings. The PCA operation was used to recover from an upset condition. In addition, PCA was tested at altitude with all three hydraulic systems turned off. This paper reviews the principles of throttles-only flight control; describes the MD-11 airplane and systems; and discusses PCA system development, operation, flight testing, and pilot comments.

  9. Development and Flight Test of an Emergency Flight Control System Using Only Engine Thrust on an MD-11 Transport Airplane

    Science.gov (United States)

    Burcham, Frank W., Jr.; Burken, John J.; Maine, Trindel A.; Fullerton, C. Gordon

    1997-01-01

    An emergency flight control system that uses only engine thrust, called the propulsion-controlled aircraft (PCA) system, was developed and flight tested on an MD-11 airplane. The PCA system is a thrust-only control system, which augments pilot flightpath and track commands with aircraft feedback parameters to control engine thrust. The PCA system was implemented on the MD-11 airplane using only software modifications to existing computers. Results of a 25-hr flight test show that the PCA system can be used to fly to an airport and safely land a transport airplane with an inoperative flight control system. In up-and-away operation, the PCA system served as an acceptable autopilot capable of extended flight over a range of speeds, altitudes, and configurations. PCA approaches, go-arounds, and three landings without the use of any normal flight controls were demonstrated, including ILS-coupled hands-off landings. PCA operation was used to recover from an upset condition. The PCA system was also tested at altitude with all three hydraulic systems turned off. This paper reviews the principles of throttles-only flight control, a history of accidents or incidents in which some or all flight controls were lost, the MD-11 airplane and its systems, PCA system development, operation, flight testing, and pilot comments.

  10. Marshall Space Flight Center's Impact Testing Facility Capabilities

    Science.gov (United States)

    Finchum, Andy; Hubbs, Whitney; Evans, Steve

    2008-01-01

    Marshall Space Flight Center s (MSFC) Impact Testing Facility (ITF) serves as an important installation for space and missile related materials science research. The ITF was established and began its research in spacecraft debris shielding in the early 1960s, then played a major role in the International Space Station debris shield development. As NASA became more interested in launch debris and in-flight impact concerns, the ITF grew to include research in a variety of impact genres. Collaborative partnerships with the DoD led to a wider range of impact capabilities being relocated to MSFC as a result of the closure of Particle Impact Facilities in Santa Barbara, California. The Particle Impact Facility had a 30 year history in providing evaluations of aerospace materials and components during flights through rain, ice, and solid particle environments at subsonic through hypersonic velocities. The facility s unique capabilities were deemed a "National Asset" by the DoD. The ITF now has capabilities including environmental, ballistic, and hypervelocity impact testing utilizing an array of air, powder, and two-stage light gas guns to accommodate a variety of projectile and target types and sizes. Numerous upgrades including new instrumentation, triggering circuitry, high speed photography, and optimized sabot designs have been implemented. Other recent research has included rain drop demise characterization tests to obtain data for inclusion in on-going model development. The current and proposed ITF capabilities range from rain to micrometeoroids allowing the widest test parameter range possible for materials investigations in support of space, atmospheric, and ground environments. These test capabilities including hydrometeor, single/multi-particle, ballistic gas guns, exploding wire gun, and light gas guns combined with Smooth Particle Hydrodynamics Code (SPHC) simulations represent the widest range of impact test capabilities in the country.

  11. Vibration features of an 180 kW maglev circulator test rig

    International Nuclear Information System (INIS)

    Su Jiageng; Li Hongwei; Shi Qian; Sha Honglei; Yu Suyuan

    2015-01-01

    The helium circulator is the key equipment to drive the helium gas flowing in the primary loop for energy exchange in HTGR. Active magnetic bearings (AMB) have been considered as an alternative to replace traditional mechanical bearings in the helium circulator. Such contactless bearings do not have frictional wear and can be used to suppress vibration in rotor-dynamic applications. It is necessary to study the vibration characteristics of the maglev helium circulator to guarantee the reactor safety. Therefore, a maglev circulator test rig was built. The power of the circulator is 180 kW and the maximum speed is 17000 rpm. For the time being, the test atmosphere is air. In this paper the test rig was introduced. Vibration test work of the maglev circulator was also carried out. The measuring points were arranged at the seat because the seat vibration level is important to evaluate the machine noise. The measuring points were also arranged at the base of the circulator housing to better study the vibration characteristics. The vibrations were measured by the LC-8024 multichannel machinery diagnoses system. At each measuring point the vibrations were detected in three directions (X, Y and Z) with the vibration acceleration sensors. The test speeds varied from 1000 rpm to 17000 rpm with an increase of 1000 rpm each time. The vibration values of the seat are from 89.5 dB at 1000 rpm to 113.3 dB at 17000 rpm. The test results showed that the maglev circulator exhibits good vibration properties. This work will offer important theoretical base and engineering experience to explore the high-speed helium circulator in HTGR. (author)

  12. Multimodal Displays for Target Localization in a Flight Test

    National Research Council Canada - National Science Library

    Tannen, Robert

    2001-01-01

    ... Synthesized Immersion Research Environment (SIRE) facility. Twelve pilots with a mean of 2652 flight hours performed a simulated flight task in which they were instructed to maintain a prescribed flight path, air speed, and altitude...

  13. LISA and its in-flight test precursor SMART-2

    International Nuclear Information System (INIS)

    Vitale, S.; Bender, P.; Brillet, A.; Buchman, S.; Cavalleri, A.; Cerdonio, M.; Cruise, M.; Cutler, C.; Danzmann, K.; Dolesi, R.; Folkner, W.; Gianolio, A.; Jafry, Y.; Hasinger, G.; Heinzel, G.; Hogan, C.; Hueller, M.; Hough, J.; Phinney, S.; Prince, T.; Richstone, D.; Robertson, D.; Rodrigues, M.; Ruediger, A.; Sandford, M.; Schilling, R.; Shoemaker, D.; Schutz, B.; Stebbins, R.; Stubbs, C.; Sumner, T.; Thorne, K.; Tinto, M.; Touboul, P.; Ward, H.; Weber, W.; Winkler, W.

    2002-01-01

    LISA will be the first space-home gravitational wave observatory. It aims to detect gravitational waves in the 0.1 mHz/1 Hz range from sources including galactic binaries, super-massive black-hole binaries, capture of objects by super-massive black-holes and stochastic background. LISA is an ESA approved Cornerstone Mission foreseen as a joint ESA-NASA endeavour to be launched in 2010-11. The principle of operation of LISA is based on laser ranging of test-masses under pure geodesic motion. Achieving pure geodesic motion at the level requested for LISA, 3x10 -15 ms -2 /√Hz at 0.1 mHz, is considered a challenging technological objective. To reduce the risk, both ESA and NASA are pursuing an in-flight test of the relevant technology. The goal of the test is to demonstrate geodetic motion within one order of magnitude from the LISA performance. ESA has given this test as the primary goal of its technology dedicated mission SMART-2 with a launch in 2006. This paper describes the basics of LISA, its key technologies, and its in-flight precursor test on SMART-2

  14. Low Density Supersonic Decelerator (LDSD) Supersonic Flight Dynamics Test (SFDT) Plume Induced Environment Modelling

    Science.gov (United States)

    Mobley, B. L.; Smith, S. D.; Van Norman, J. W.; Muppidi, S.; Clark, I

    2016-01-01

    Provide plume induced heating (radiation & convection) predictions in support of the LDSD thermal design (pre-flight SFDT-1) Predict plume induced aerodynamics in support of flight dynamics, to achieve targeted freestream conditions to test supersonic deceleration technologies (post-flight SFDT-1, pre-flight SFDT-2)

  15. NASA/FAA Tailplane Icing Program: Flight Test Report

    Science.gov (United States)

    Ratvasky, Thomas P.; VanZante, Judith Foss; Sim, Alex

    2000-01-01

    This report presents results from research flights that explored the characteristics of an ice-contaminated tailplane using various simulated ice shapes attached to the leading edge of the horizontal tailplane. A clean leading edge provided the baseline case, then three ice shapes were flown in order of increasing severity. Flight tests included both steady state and dynamic maneuvers. The steady state points were 1G wings level and steady heading sideslips. The primary dynamic maneuvers were pushovers to various G-levels; elevator doublets; and thrust transitions. These maneuvers were conducted for a full range of flap positions and aircraft angle of attack where possible. The analysis of this data set has clearly demonstrated the detrimental effects of ice contamination on aircraft stability and controllability. Paths to tailplane stall were revealed through parameter isolation and transition studies. These paths are (1) increasing ice shape severity, (2) increasing flap deflection, (3) high or low speeds, depending on whether the aircraft is in a steady state (high speed) or pushover maneuver (low speed), and (4) increasing thrust. The flight research effort was very comprehensive, but did not examine effects of tailplane design and location, or other aircraft geometry configuration effects. However, this effort provided the role of some of the parameters in promoting tailplane stall. The lessons learned will provide guidance to regulatory agencies, aircraft manufacturers, and operators on ice-contaminated tailplane stall in the effort to increase aviation safety and reduce the fatal accident rate.

  16. Airborne Turbulence Detection and Warning ACLAIM Flight Test Results

    Science.gov (United States)

    Hannon, Stephen M.; Bagley, Hal R.; Soreide, Dave C.; Bowdle, David A.; Bogue, Rodney K.; Ehernberger, L. Jack

    1999-01-01

    The Airborne Coherent Lidar for Advanced Inflight Measurements (ACLAIM) is a NASA/Dryden-lead program to develop and demonstrate a 2 micrometers pulsed Doppler lidar for airborne look-ahead turbulence detection and warning. Advanced warning of approaching turbulence can significantly reduce injuries to passengers and crew aboard commercial airliners. The ACLAIM instrument is a key asset to the ongoing Turbulence component of NASA's Aviation Safety Program, aimed at reducing the accident rate aboard commercial airliners by a factor of five over the next ten years and by a factor of ten over the next twenty years. As well, the advanced turbulence warning capability can prevent "unstarts" in the inlet of supersonic aircraft engines by alerting the flight control computer which then adjusts the engine to operate in a less fuel efficient, and more turbulence tolerant, mode. Initial flight tests of the ACLAIM were completed in March and April of 1998. This paper and presentation gives results from these initial flights, with validated demonstration of Doppler lidar wind turbulence detection several kilometers ahead of the aircraft.

  17. Development and flight testing of UV optimized Photon Counting CCDs

    Science.gov (United States)

    Hamden, Erika T.

    2018-06-01

    I will discuss the latest results from the Hamden UV/Vis Detector Lab and our ongoing work using a UV optimized EMCCD in flight. Our lab is currently testing efficiency and performance of delta-doped, anti-reflection coated EMCCDs, in collaboration with JPL. The lab has been set-up to test quantum efficiency, dark current, clock-induced-charge, and read noise. I will describe our improvements to our circuit boards for lower noise, updates from a new, more flexible NUVU controller, and the integration of an EMCCD in the FIREBall-2 UV spectrograph. I will also briefly describe future plans to conduct radiation testing on delta-doped EMCCDs (both warm, unbiased and cold, biased configurations) thus summer and longer term plans for testing newer photon counting CCDs as I move the HUVD Lab to the University of Arizona in the Fall of 2018.

  18. Preliminary flight test results of a fly-by-throttle emergency flight control system on an F-15 airplane

    Science.gov (United States)

    Burcham, Frank W., Jr.; Maine, Trindel A.; Fullerton, C. G.; Wells, Edward A.

    1993-01-01

    A multi-engine aircraft, with some or all of the flight control system inoperative, may use engine thrust for control. NASA Dryden has conducted a study of the capability and techniques for this emergency flight control method for the F-15 airplane. With an augmented control system, engine thrust, along with appropriate feedback parameters, is used to control flightpath and bank angle. Extensive simulation studies have been followed by flight tests. This paper discusses the principles of throttles-only control, the F-15 airplane, the augmented system, and the flight results including landing approaches with throttles-only control to within 10 ft of the ground.

  19. Damping Estimation Using Free Decays and Ambient Vibration Tests

    DEFF Research Database (Denmark)

    Magalhães, Filipe; Brincker, Rune; Cunha, Álvaro

    2007-01-01

    The accurate identification of modal damping ratios of Civil Engineering structures is a subject of major importance, as the amplitude of structural vibrations in resonance is inversely proportional to these coefficients. Their experimental identification can be performed either from ambient vibr...

  20. A General Purpose Digital System for Field Vibration Testing

    DEFF Research Database (Denmark)

    Brincker, Rune; Larsen, Jesper Abildgaard; Ventura, Carlos

    2007-01-01

    This paper describes the development and concept implementation of a highly sensitive digital recording system for seismic applications and vibration measurements on large Civil Engineering structures. The system is based on highly sensitive motion transducers that have been used by seismologists...

  1. Low frequency vibration tests on a floating slab track in an underground laboratory

    Institute of Scientific and Technical Information of China (English)

    De-yun DING; Wei-ning LIU; Ke-fei LI; Xiao-jing SUN; Wei-feng LIU

    2011-01-01

    Low frequency vibrations induced by underground railways have attracted increasing attention in recent years. To obtain the characteristics of low frequency vibrations and the low frequency performance of a floating slab track (FST), low frequency vibration tests on an FST in an underground laboratory at Beijing Jiaotong University were carried out. The FST and an unbalanced shaker SBZ30 for dynamic simulation were designed for use in low frequency vibration experiments. Vibration measurements were performed on the bogie of the unbalanced shaker, the rail, the slab, the tunnel invert, the tunnel wall, the tunnel apex, and on the ground surface at distances varying from 0 to 80 m from the track. Measurements were also made on several floors of an adjacent building. Detailed results of low frequency vibration tests were reported. The attenuation of low frequency vibrations with the distance from the track was presented, as well as the responses of different floors of the building. The experimental results could be regarded as a reference for developing methods to control low frequency vibrations and for adopting countermeasures.

  2. Relative sensory sparing in the diabetic foot implied through vibration testing

    Directory of Open Access Journals (Sweden)

    Todd O'Brien

    2013-09-01

    Full Text Available Background: The dorsal aspect of the hallux is often cited as the anatomic location of choice for vibration testing in the feet of diabetic patients. To validate this preference, vibration tests were performed and compared at the hallux and 5th metatarsal head in diabetic patients with established neuropathy. Methods: Twenty-eight neuropathic, diabetic patients and 17 non-neuropathic, non-diabetic patients underwent timed vibration testing (TVT with a novel 128 Hz electronic tuning fork (ETF at the hallux and 5th metatarsal head. Results: TVT values in the feet of diabetic patients were found to be reduced at both locations compared to controls. Unexpectedly, these values were significantly lower at the hallux (P < 0.001 compared to the 5th metatarsal head. Conclusion: This study confirms the hallux as the most appropriate location for vibration testing and implies relative sensory sparing at the 5th metatarsal head, a finding not previously reported in diabetic patients.

  3. Performance of Different Sensors for Monitoring of the Vibration Generated during Thermosonic Non-destructive Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Bu Byoung [Korea Railroad Research Institute, Uiwang (Korea, Republic of)

    2011-04-15

    Vibration monitoring is required for reliable thermosonic testing to decide whether sufficient vibration is achieved in each test for the detection of cracks. From a practical point of view, a cheaper and convenient monitoring method is better for the application to real tests. Therefore, the performance of different sensors for vibration monitoring was investigated and compared in this study to find a convenient and acceptable measurement method for thermosonics. Velocity measured by a laser vibrometer and strain provide an equivalent HI when measured at the same position. The microphone can provide a cheaper vibration monitoring device than the laser and the heating index calculated by a microphone signal shows similar characteristics to that calculated from velocity measured by the laser vibrometer. The microphone frequency response shows that it underestimates high frequency components but it is applicable to practical tests because it gives a conservative value of HI

  4. Forced vibration tests on the reactor building of a nuclear power station, 1

    International Nuclear Information System (INIS)

    Takeda, Toshikazu; Tsunoda, Tomohiko; Wakamatsu, Kunio; Kaneko, Masataka; Nakamura, Mitsuru; Kunoh, Toshio; Murahashi, Hisahiro

    1988-01-01

    Tsuruga Unit No.2 Nuclear Power Station of the Japan Atomic Power Company is the first PWR-type 4-loop plant constructed in Japan with a prestressed concrete containment vessel (PCCV). This report describes forced vibration tests carried out on the reactor building of this plant. The following were obtained as results: (1) The results of the forced vibration tests corresponded well on the whole with design values. (2) The vibration characteristics of the PCCV observed in the tests after prestressing are no different from the ones before prestressing. This shows that the vibration properties of the PCCV are practically independent of prestressing loads. (3) A seismic response analysis of the design basis earthquake was made on the design model reflecting the test results. The seismic safety of the plant was confirmed by this analysis. (author)

  5. Test-Anchored Vibration Response Predictions for an Acoustically Energized Curved Orthogrid Panel with Mounted Components

    Science.gov (United States)

    Frady, Gregory P.; Duvall, Lowery D.; Fulcher, Clay W. G.; Laverde, Bruce T.; Hunt, Ronald A.

    2011-01-01

    rich body of vibroacoustic test data was recently generated at Marshall Space Flight Center for component-loaded curved orthogrid panels typical of launch vehicle skin structures. The test data were used to anchor computational predictions of a variety of spatially distributed responses including acceleration, strain and component interface force. Transfer functions relating the responses to the input pressure field were generated from finite element based modal solutions and test-derived damping estimates. A diffuse acoustic field model was applied to correlate the measured input sound pressures across the energized panel. This application quantifies the ability to quickly and accurately predict a variety of responses to acoustically energized skin panels with mounted components. Favorable comparisons between the measured and predicted responses were established. The validated models were used to examine vibration response sensitivities to relevant modeling parameters such as pressure patch density, mesh density, weight of the mounted component and model form. Convergence metrics include spectral densities and cumulative root-mean squared (RMS) functions for acceleration, velocity, displacement, strain and interface force. Minimum frequencies for response convergence were established as well as recommendations for modeling techniques, particularly in the early stages of a component design when accurate structural vibration requirements are needed relatively quickly. The results were compared with long-established guidelines for modeling accuracy of component-loaded panels. A theoretical basis for the Response/Pressure Transfer Function (RPTF) approach provides insight into trends observed in the response predictions and confirmed in the test data. The software developed for the RPTF method allows easy replacement of the diffuse acoustic field with other pressure fields such as a turbulent boundary layer (TBL) model suitable for vehicle ascent. Structural responses

  6. Kodak Mirror Assembly Tested at Marshall Space Flight Center

    Science.gov (United States)

    2003-01-01

    This photo (a frontal view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

  7. Tests and calibration of NIF neutron time of flight detectors.

    Science.gov (United States)

    Ali, Z A; Glebov, V Yu; Cruz, M; Duffy, T; Stoeckl, C; Roberts, S; Sangster, T C; Tommasini, R; Throop, A; Moran, M; Dauffy, L; Horsefield, C

    2008-10-01

    The National Ignition Facility (NIF) neutron time of flight (NTOF) diagnostic will measure neutron yield and ion temperature in all NIF campaigns in DD, DT, and THD(*) implosions. The NIF NTOF diagnostic is designed to measure neutron yield from 1x10(9) to 2x10(19). The NTOF consists of several detectors of varying sensitivity located on the NIF at about 5 and 20 m from the target. Production, testing, and calibration of the NIF NTOF detectors have begun at the Laboratory for Laser Energetics (LLE). Operational tests of the NTOF detectors were performed on several facilities including the OMEGA laser at LLE and the Titan laser at Lawrence Livermore National Laboratory. Neutron calibrations were carried out on the OMEGA laser. Results of the NTOF detector tests and calibration will be presented.

  8. Verification of hybrid analysis concept of soil-foundation interaction by field vibration tests - Analytical phase

    International Nuclear Information System (INIS)

    Katayama, I.; Niwa, A.; Kubo, Y.; Penzien, J.

    1987-01-01

    In connection with the previous paper under the same subject, which describes the results obtained by the field vibration tests of five different models, this paper describes the outline of the hybrid analysis code of soil-structure interaction (HASSI) and the results of numerical simulation of the responses obtained at the model 2C in both cases of the forced vibration test and the natural earthquake excitation

  9. Comparison of vibration test results for Atucha II NPP and large scale concrete block models

    International Nuclear Information System (INIS)

    Iizuka, S.; Konno, T.; Prato, C.A.

    2001-01-01

    In order to study the soil structure interaction of reactor building that could be constructed on a Quaternary soil, a comparison study of the soil structure interaction springs was performed between full scale vibration test results of Atucha II NPP and vibration test results of large scale concrete block models constructed on Quaternary soil. This comparison study provides a case data of soil structure interaction springs on Quaternary soil with different foundation size and stiffness. (author)

  10. Correlation analysis for forced vibration test of the Hualien large scale seismic test (LSST) program

    International Nuclear Information System (INIS)

    Sugawara, Y.; Sugiyama, T.; Kobayashi, T.; Yamaya, H.; Kitamura, E.

    1995-01-01

    The correlation analysis for a forced vibration test of a 1/4-scale containment SSI test model constructed in Hualien, Taiwan was carried out for the case of after backfilling. Prior to this correlation analysis, the structural properties were revised to adjust the calculated fundamental frequency in the fixed base condition to that derived from the test results. A correlation analysis was carried out using the Lattice Model which was able to estimate the soil-structure effects with embedment. The analysis results coincide well with test results and it is concluded that the mathematical soil-structure interaction model established by the correlation analysis is efficient in estimating the dynamic soil-structure interaction effect with embedment. This mathematical model will be applied as a basic model for simulation analysis of earthquake observation records. (author). 3 refs., 12 figs., 2 tabs

  11. Vibration test report for in-chimney bracket and instrumented fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jeong Soo; Yoon, D. B.; Cho, Y. G.; Ahn, G. H.; Lee, J. H.; Park, J.H

    2000-10-01

    The vibration levels of in-chimney bracket structure which is installed in reactor chimney and instrumented fuel assembly(Type-B Bundle) are investigated under the steady state normal operating condition of the reactor. For this purpose, 4 acceleration data on the guide tube of the instrumented fuel assembly and in-chimney bracket structures subjected to fluid induced vibration are measured. For the analysis of the vibration data, vibration analysis program which can perform basic time and frequency domain analysis, is prepared, and its reliability is verified by comparing the analysis results with those of commercial analysis program(I-DEAS). In time domain analysis, maximum amplitudes, and RMS values of accelerations and displacements from the measured vibration signal, are obtained. The frequency components of the vibration data are analyzed by using the frequency domain analysis. These analysis results show that the levels of the measured vibrations are within the allowable level, and the low frequency component near 10 Hz is dominant in the vibration signal. For the evaluation of the structural integrity on the in-chimney bracket and related structures including the instrumented fuel assembly, the static analysis for ANSYS finite element model is carried out. These analysis results show that the maximum stresses are within the allowable stresses of the ASME code, and the maximum displacement of the top of the flow tube is within the displacement limit. Therefore any damage on the structural integrity is not expected when the irradiation test is performed using the in-chimney bracket.

  12. Vibration test report for in-chimney bracket and instrumented fuel assembly

    International Nuclear Information System (INIS)

    Ryu, Jeong Soo; Yoon, D. B.; Cho, Y. G.; Ahn, G. H.; Lee, J. H.; Park, J.H.

    2000-10-01

    The vibration levels of in-chimney bracket structure which is installed in reactor chimney and instrumented fuel assembly(Type-B Bundle) are investigated under the steady state normal operating condition of the reactor. For this purpose, 4 acceleration data on the guide tube of the instrumented fuel assembly and in-chimney bracket structures subjected to fluid induced vibration are measured. For the analysis of the vibration data, vibration analysis program which can perform basic time and frequency domain analysis, is prepared, and its reliability is verified by comparing the analysis results with those of commercial analysis program(I-DEAS). In time domain analysis, maximum amplitudes, and RMS values of accelerations and displacements from the measured vibration signal, are obtained. The frequency components of the vibration data are analyzed by using the frequency domain analysis. These analysis results show that the levels of the measured vibrations are within the allowable level, and the low frequency component near 10 Hz is dominant in the vibration signal. For the evaluation of the structural integrity on the in-chimney bracket and related structures including the instrumented fuel assembly, the static analysis for ANSYS finite element model is carried out. These analysis results show that the maximum stresses are within the allowable stresses of the ASME code, and the maximum displacement of the top of the flow tube is within the displacement limit. Therefore any damage on the structural integrity is not expected when the irradiation test is performed using the in-chimney bracket

  13. FIVPET Flow-Induced Vibration Test Report (1) - Candidate Spacer Grid Type I (Optimized H Type)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Hee; Kang, Heung Seok; Yoon, Kyung Ho; Song, Kee Nam; Kim, Jae Yong

    2006-03-15

    The flow-induced vibration (FIV) test using a 5x5 partial fuel assembly was performed to evaluate mechanical/structural performance of the candidate spacer grid type I (Optimized H shape). From the measured vibration response of the test bundle and the flow parameters, design features of the spacer strap can be analyzed in the point of vibration and hydraulic aspect, and also compared with other spacer strap in simple comparative manner. Furthermore, the FIV test will contributes to understand behaviors of nuclear fuel in operating reactor. The FIV test results will be used to verify the theoretical model of fuel rod and assembly vibration. The aim of this report is to present the results of the FIV test of partial fuel assembly and to introduce the detailed test methodology and analysis procedure. In chapter 2, the overall configuration of test bundle and instrumented tube is remarked and chapter 3 will introduce the test facility (FIVPET) and test section. Chapter 4 deals with overall test condition and procedure, measurement and data acquisition devices, instrumentation equipment and calibration, and error analysis. Finally, test result of vibration and pressure fluctuation is presented and discussed in chapter 5.

  14. Flight tests of a supersonic natural laminar flow airfoil

    International Nuclear Information System (INIS)

    Frederick, M A; Banks, D W; Garzon, G A; Matisheck, J R

    2015-01-01

    A flight test campaign of a supersonic natural laminar flow airfoil has been recently completed. The test surface was an 80 inch (203 cm) chord and 40 inch (102 cm) span article mounted on the centerline store location of an F-15B airplane. The test article was designed with a leading edge sweep of effectively 0° to minimize boundary layer crossflow. The test article surface was coated with an insulating material to avoid significant heat transfer to and from the test article structure to maintain a quasi-adiabatic wall. An aircraft-mounted infrared camera system was used to determine boundary layer transition and the extent of laminar flow. The tests were flown up to Mach 2.0 and chord Reynolds numbers in excess of 30 million. The objectives of the tests were to determine the extent of laminar flow at high Reynolds numbers and to determine the sensitivity of the flow to disturbances. Both discrete (trip dots) and 2D disturbances (forward-facing steps) were tested. A series of oblique shocks, of yet unknown origin, appeared on the surface, which generated sufficient crossflow to affect transition. Despite the unwanted crossflow, the airfoil performed well. The results indicate that the sensitivity of the flow to the disturbances, which can translate into manufacturing tolerances, was similar to that of subsonic natural laminar flow wings. (paper)

  15. Pre-Flight Ground Testing of the Full-Scale HIFiRE-1 at Fully Duplicated Flight Conditions

    National Research Council Canada - National Science Library

    Wadhams, Tim P; MacLean, Matthew G; Holden, Michael S; Mundy, Erik

    2008-01-01

    As part of an experimental study to obtain detailed heating and pressure data over the full-scale HIFiRE-1 flight geometry, CUBRC has completed a 30-run matrix of ground tests, sponsored by the AFOSR...

  16. Digital virtual flight testing and evaluation method for flight characteristics airworthiness compliance of civil aircraft based on HQRM

    Directory of Open Access Journals (Sweden)

    Fan Liu

    2015-02-01

    Full Text Available In order to incorporate airworthiness requirements for flight characteristics into the entire development cycle of electronic flight control system (EFCS equipped civil aircraft, digital virtual flight testing and evaluation method based on handling qualities rating method (HQRM is proposed. First, according to HQRM, flight characteristics airworthiness requirements of civil aircraft in EFCS failure states are determined. On this basis, digital virtual flight testing model, comprising flight task digitized model, pilot controlling model, aircraft motion and atmospheric turbulence model, is used to simulate the realistic process of a pilot controlling an airplane to perform assigned flight tasks. According to the simulation results, flight characteristics airworthiness compliance of the airplane can be evaluated relying on the relevant regulations for handling qualities (HQ rating. Finally, this method is applied to a type of passenger airplane in a typical EFCS failure state, and preliminary conclusions concerning airworthiness compliance are derived quickly. The research results of this manuscript can provide important theoretical reference for EFCS design and actual airworthiness compliance verification of civil aircraft.

  17. Vibrational multiconfiguration self-consistent field theory: implementation and test calculations.

    Science.gov (United States)

    Heislbetz, Sandra; Rauhut, Guntram

    2010-03-28

    A state-specific vibrational multiconfiguration self-consistent field (VMCSCF) approach based on a multimode expansion of the potential energy surface is presented for the accurate calculation of anharmonic vibrational spectra. As a special case of this general approach vibrational complete active space self-consistent field calculations will be discussed. The latter method shows better convergence than the general VMCSCF approach and must be considered the preferred choice within the multiconfigurational framework. Benchmark calculations are provided for a small set of test molecules.

  18. Design and Test of Semi-Active Vibration-Reducing System for Lathe

    Directory of Open Access Journals (Sweden)

    Hongsheng Hu

    2014-09-01

    Full Text Available In this paper, its theory design, analysis and test system of semi-active vibration controlling system used for precision machine have been done. Firstly, lathe bed and spindle entity were modeled by using UG software; Then modes of the machine bed and the key components of spindle were obtained by using ANSYS software; Finally, harmonic response analysis of lathe spindle under complex load was acquired, which provided a basis of MR damper’s structure optimization design for a certain type of precision machine. In order to prove its effectives, a prototype semi-active vibration controlling lathe with MR damper was developed. Tests have been done, and comparison results between passive vibration isolation equipment and semi-active vibration controlling equipment proved its good performances of MR damper.

  19. Overheating Anomalies during Flight Test Due to the Base Bleeding

    Science.gov (United States)

    Luchinsky, Dmitry; Hafiychuck, Halyna; Osipov, Slava; Ponizhovskaya, Ekaterina; Smelyanskiy, Vadim; Dagostino, Mark; Canabal, Francisco; Mobley, Brandon L.

    2012-01-01

    In this paper we present the results of the analytical and numerical studies of the plume interaction with the base flow in the presence of base out-gassing. The physics-based analysis and CFD modeling of the base heating for single solid rocket motor performed in this research addressed the following questions: what are the key factors making base flow so different from that in the Shuttle [1]; why CFD analysis of this problem reveals small plume recirculation; what major factors influence base temperature; and why overheating was initiated at a given time in the flight. To answer these questions topological analysis of the base flow was performed and Korst theory was used to estimate relative contributions of radiation, plume recirculation, and chemically reactive out-gassing to the base heating. It was shown that base bleeding and small base volume are the key factors contributing to the overheating, while plume recirculation is effectively suppressed by asymmetric configuration of the flow formed earlier in the flight. These findings are further verified using CFD simulations that include multi-species gas environment both in the plume and in the base. Solid particles in the exhaust plume (Al2O3) and char particles in the base bleeding were also included into the simulations and their relative contributions into the base temperature rise were estimated. The results of simulations are in good agreement with the temperature and pressure in the base measured during the test.

  20. Bony vibration stimulation test combined with magnetic resonance imaging. Can discography be replaced?

    Science.gov (United States)

    Yrjämä, M; Tervonen, O; Kurunlahti, M; Vanharanta, H

    1997-04-01

    The results of two noninvasive methods, magnetic resonance imaging and a bony vibration test, were compared with discographic pain provocation findings. To evaluate whether the combination of magnetic resonance imaging and vibration pain provocation tests could be used to replace discography in low back pain diagnostics. Magnetic resonance imaging gives a wealth of visual information on anatomic changes of the spine with often unknown clinical significance. Discographic examination of the spine is still the only widely accepted diagnostic method that can relate the pathoanatomic changes to the patient's clinical pain. Internal anular rupture has been shown to be one of the sources of back pain. The bony vibration test of the spinal processes has been shown correlate well with discographic pain provocation tests in cases of internal anular rupture. The three lowest lumbar discs of 33 patients with back pain were examined by means of magnetic resonance imaging and a bony vibration stimulation test, and the results were compared with those from computed tomography-discography. In cases of intradiscal magnetic resonance imaging findings, the vibration provocation test showed a sensitivity of 0.88 and a specificity of 0.50 compared with the discographic pain provocation test. If the patients with previous back surgery were excluded, the specificity was 0.75. In the cases of total anular rupture, the sensitivity was 0.50, and the specificity was 0.33. The combination of the two noninvasive methods, vibration stimulation and magnetic resonance imaging, gives more information on the origin of the back pain than magnetic resonance imaging alone. The pathoanatomic changes seen in magnetic resonance imaging can be correlated with the patient's disorder more reliably using the vibration provocation test in the cases of partial anular ruptures. The use of discography can be limited mostly to cases with total anular ruptures detected by magnetic resonance imaging.

  1. Testing and diagnosis of the cause of increased vibration of the fan plant's support structure

    Directory of Open Access Journals (Sweden)

    Varju Đerđ

    2015-01-01

    Full Text Available This paper presents a procedure of determining the causes of increased vibration of a fan plant and its support structure in the PUC 'Subotička toplana'. Excessive vibrations were observed following the installation of the frequency converter, thus a methodological approach of testing-analysis-diagnosis has been applied. Based on the definition of the causes of this problem, the paper also suggests possible repair procedures.

  2. Application of Finite Element Based Simulation and Modal Testing Methods to Improve Vehicle Powertrain Idle Vibration

    Directory of Open Access Journals (Sweden)

    Polat Sendur

    2017-01-01

    Full Text Available Current practice of analytical and test methods related to the analysis, testing and improvement of vehicle vibrations is overviewed. The methods are illustrated on the determination and improvement of powertrain induced steering wheel vibration of a heavy commercial truck. More specifically, the transmissibility of powertrain idle vibration to cabin is investigated with respect to powertrain rigid body modes and modal alignment of the steering column/wheel system is considered. It is found out that roll mode of the powertrain is not separated from idle excitation for effective vibration isolation as well as steering wheel column mode is close to the 3rd engine excitation frequency order, which results in high vibration levels. Powertrain roll mode is optimized by tuning the powertrain mount stiffness to improve the performance. Steering column mode is also separated from the 3rd engine excitation frequency by the application of a mass absorber. It is concluded that the use of analytical and test methods to address the complex relation between design parameters and powertrain idle response is effective to optimize the system performance and evaluate the trade-offs in the vehicle design such as vibration performance and weight. Reference Number: www.asrongo.org/doi:4.2017.2.1.10

  3. Forced vibration test on large scale model on soft rock site

    International Nuclear Information System (INIS)

    Kobayashi, Toshio; Fukuoka, Atsunobu; Izumi, Masanori; Miyamoto, Yuji; Ohtsuka, Yasuhiro; Nasuda, Toshiaki.

    1991-01-01

    Forced vibration tests were conducted in order to investigate the embedment effect on dynamic soil-structure interaction. Two model structures were constructed on actual soil about 60 m apart, after excavating the ground to 5 m depth. For both models, the sinusoidal forced vibration tests were performed with the conditions of different embedment depth, namely non-embedment, half-embedment and full-embedment. As the test results, the increase in both natural frequency and damping factor due to the embedment effects can be observed, and the soil impedances calculated from test results are discussed. (author)

  4. Vibration test of spherical shell structure and replacing method into mathematical model

    International Nuclear Information System (INIS)

    Takayanagi, M.; Suzuki, S.; Okamura, T.; Haas, E.E.; Krutzik, N.J.

    1989-01-01

    To verify the beam-type and oval-type vibratory characteristics of a spherical shell structure, two test specimens were made and vibration tests were carried out. Results of these tests are compared with results of detailed analyses using 3-D FEM and 2-D axisymmetric FEM models. The analytical results of overall vibratory characteristics are in good agreement with the test results, has been found that the effect of the attached mass should be considered in evaluating local vibration. The replacing method into equivalent beam model is proposed

  5. Design and Testing of Flight Control Laws on the RASCAL Research Helicopter

    Science.gov (United States)

    Frost, Chad R.; Hindson, William S.; Moralez. Ernesto, III; Tucker, George E.; Dryfoos, James B.

    2001-01-01

    Two unique sets of flight control laws were designed, tested and flown on the Army/NASA Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) JUH-60A Black Hawk helicopter. The first set of control laws used a simple rate feedback scheme, intended to facilitate the first flight and subsequent flight qualification of the RASCAL research flight control system. The second set of control laws comprised a more sophisticated model-following architecture. Both sets of flight control laws were developed and tested extensively using desktop-to-flight modeling, analysis, and simulation tools. Flight test data matched the model predicted responses well, providing both evidence and confidence that future flight control development for RASCAL will be efficient and accurate.

  6. Orion Exploration Flight Test-1 Post-Flight Navigation Performance Assessment Relative to the Best Estimated Trajectory

    Science.gov (United States)

    Gay, Robert S.; Holt, Greg N.; Zanetti, Renato

    2016-01-01

    This paper details the post-flight navigation performance assessment of the Orion Exploration Flight Test-1 (EFT-1). Results of each flight phase are presented: Ground Align, Ascent, Orbit, and Entry Descent and Landing. This study examines the on-board Kalman Filter uncertainty along with state deviations relative to the Best Estimated Trajectory (BET). Overall the results show that the Orion Navigation System performed as well or better than expected. Specifically, the Global Positioning System (GPS) measurement availability was significantly better than anticipated at high altitudes. In addition, attitude estimation via processing GPS measurements along with Inertial Measurement Unit (IMU) data performed very well and maintained good attitude throughout the mission.

  7. Perseus B Taxi Tests in Preparation for a New Series of Flight Tests

    Science.gov (United States)

    1998-01-01

    The Perseus B remotely piloted aircraft taxis on the runway at Edwards Air Force Base, California, before a series of development flights at NASA's Dryden flight Research Center. The Perseus B is the latest of three versions of the Perseus design developed by Aurora Flight Sciences under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus

  8. Vibration tests and analyses of the reactor building model on a small scale

    International Nuclear Information System (INIS)

    Tsuchiya, Hideo; Tanaka, Mitsuru; Ogihara, Yukio; Moriyama, Ken-ichi; Nakayama, Masaaki

    1985-01-01

    The purpose of this paper is to describe the vibration tests and the simulation analyses of the reactor building model on a small scale. The model vibration tests were performed to investigate the vibrational characteristics of the combined super-structure and to verify the computor code based on Dr. H. Tajimi's Thin Layered Element Theory, using the uniaxial shaking table (60 cm x 60 cm). The specimens consist of ground model, three structural model (prestressed concrete containment vessel, inner concrete structure, and enclosure building), a combined structural model and a combined structure-soil interaction model. These models are made of silicon-rubber, and they have a scale of 1:600. Harmonic step by step excitation of 40 gals was performed to investigate the vibrational characteristics for each structural model. The responses of the specimen to harmonic excitation were measured by optical displacement meters, and analyzed by a real time spectrum analyzer. The resonance and phase lag curves of the specimens to the shaking table were obtained respectively. As for the tests of a combined structure-soil interaction model, three predominant frequencies were observed in the resonance curves. These values were in good agreement with the analytical transfer function curves on the computer code. From the vibration tests and the simulation analyses, the silicon-rubber model test is useful for the fundamental study of structural problems. The computer code based on the Thin Element Theory can simulate well the test results. (Kobozono, M.)

  9. Large scale vibration tests on pile-group effects using blast-induced ground motion

    International Nuclear Information System (INIS)

    Katsuichirou Hijikata; Hideo Tanaka; Takayuki Hashimoto; Kazushige Fujiwara; Yuji Miyamoto; Osamu Kontani

    2005-01-01

    Extensive vibration tests have been performed on pile-supported structures at a large-scale mining site. Ground motions induced by large-scale blasting operations were used as excitation forces for vibration tests. The main objective of this research is to investigate the dynamic behavior of pile-supported structures, in particular, pile-group effects. Two test structures were constructed in an excavated 4 m deep pit. Their test-structures were exactly the same. One structure had 25 steel piles and the other had 4 piles. The test pit was backfilled with sand of appropriate grain size distributions to obtain good compaction, especially between the 25 piles. Accelerations were measured at the structures, in the test pit and in the adjacent free field, and pile strains were measured. Dynamic modal tests of the pile-supported structures and PS measurements of the test pit were performed before and after the vibration tests to detect changes in the natural frequencies of the soil-pile-structure systems and the soil stiffness. The vibration tests were performed six times with different levels of input motions. The maximum horizontal acceleration recorded at the adjacent ground surface varied from 57 cm/s 2 to 1,683 cm/s 2 according to the distances between the test site and the blast areas. (authors)

  10. Ground vibration test results for Drones for Aerodynamic and Structural Testing (DAST)/Aeroelastic Research Wing (ARW-1R) aircraft

    Science.gov (United States)

    Cox, T. H.; Gilyard, G. B.

    1986-01-01

    The drones for aerodynamic and structural testing (DAST) project was designed to control flutter actively at high subsonic speeds. Accurate knowledge of the structural model was critical for the successful design of the control system. A ground vibration test was conducted on the DAST vehicle to determine the structural model characteristics. This report presents and discusses the vibration and test equipment, the test setup and procedures, and the antisymmetric and symmetric mode shape results. The modal characteristics were subsequently used to update the structural model employed in the control law design process.

  11. Radiometric and ultrasonic testing of vibrating roller compacting effects

    International Nuclear Information System (INIS)

    Prikryl, F.; Habarta, J.; Kovarikova, E.

    1977-01-01

    A hole was filled with two layers of concrete mixture. Each layer was compacted using a Dynapac CA 25 vibrating roller 10,000 kg in weight, operating with a frequency of 30 Hz. A concrete block thus produced had dimensions of 11.0x2.5 m and a height of 1.6 m. After the concrete block hardening (roughly 120 days) drill cores were bored and bulk density was determined using nondestructive methods. Bulk density determination of the concrete between the drill cores was conducted using a 137 Cs emitter of an activity of 89 GBq, a FHZ-88b Geiger-Mueller counter was used as the detector. The emitter and detector were placed to touch the bore wall and were lowered to different depths in 10 cm increments. 10 count rate values were measured in each depth. The measurement time was chosen such that the decay statistical error did not exceed 1;. Bulk density of the individual segments of the drill cores was determined using 60 Co of an activitBy of 55 Mq as the radiation source and a TESLA 20/100 GWl GM counter as the detector. The detector operating voltage was 1240 V. Ultrasonic measurements were conducted using the USME-5 instrument. The measured bulk density values show that the compacting of a concrete layer 80 cm in thickness using a vibrating roller is sufficiently efficient. Both nondestructive methods were well proven, the results show that bulk density values in different depths differ due to concrete moisture content. (J.P.)

  12. Incorporating Vibration Test Results for the Advanced Stirling Convertor into the System Dynamic Model

    Science.gov (United States)

    Meer, David W.; Lewandowski, Edward J.

    2010-01-01

    The U.S. Department of Energy (DOE), Lockheed Martin Corporation (LM), and NASA Glenn Research Center (GRC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. As part of the extended operation testing of this power system, the Advanced Stirling Convertors (ASC) at NASA GRC undergo a vibration test sequence intended to simulate the vibration history that an ASC would experience when used in an ASRG for a space mission. During these tests, a data system collects several performance-related parameters from the convertor under test for health monitoring and analysis. Recently, an additional sensor recorded the slip table position during vibration testing to qualification level. The System Dynamic Model (SDM) integrates Stirling cycle thermodynamics, heat flow, mechanical mass, spring, damper systems, and electrical characteristics of the linear alternator and controller. This Paper presents a comparison of the performance of the ASC when exposed to vibration to that predicted by the SDM when exposed to the same vibration.

  13. Shock and vibration tests of uranium mononitride fuel pellets for a space power nuclear reactor

    Science.gov (United States)

    Adams, D. W.

    1972-01-01

    Shock and vibration tests were conducted on cylindrically shaped, depleted, uranium mononitride (UN) fuel pellets. The structural capabilities of the pellets were determined under exposure to shock and vibration loading which a nuclear reactor may encounter during launching into space. Various combinations of diametral and axial clearances between the pellets and their enclosing structures were tested. The results of these tests indicate that for present fabrication of UN pellets, a diametral clearance of 0.254 millimeter and an axial clearance of 0.025 millimeter are tolerable when subjected to launch-induced loads.

  14. Experimental Analysis of Mast Lifting and Bending Forces on Vibration Patterns Before and After Pinion Reinstallation in an OH-58 Transmission Test Rig

    Science.gov (United States)

    Huff, Edward M.; Lewicki, David G.; Tumer, Irem Y.; Decker, Harry; Barszez, Eric; Zakrajsek, James J.; Norvig, Peter (Technical Monitor)

    2000-01-01

    As part of a collaborative research program between NASA Ames Research Center (ARC), NASA Glenn Research Center (GRC), and the US Army Laboratory, a series of experiments is being performed in GRC's 500 HP OH-58 Transmission Test Rig facility and ARC's AH-I Cobra and OH-58c helicopters. The findings reported in this paper were drawn from Phase-I of a two-phase test-rig experiment, and are focused on the vibration response of an undamaged pinion gear operating in the transmission test rig. To simulate actual flight conditions, the transmission system was run at three torque levels, as well as two mast lifting and two mast bending levels. The test rig was also subjected to disassembly and reassembly of the main pinion housing to simulate the effect of maintenance operations. An analysis of variance based on the total power of the spectral distribution indicates the relative effect of each experimental factor, including Wong interactions with torque. Reinstallation of the main pinion assembly is shown to introduce changes in the vibration signature, suggesting the possibility of a strong effect of maintenance on HUMS design and use. Based on these results, further research will be conducted to compare these vibration responses with actual OH58c helicopter transmission vibration patterns.

  15. Aerodynamic Flight-Test Results for the Adaptive Compliant Trailing Edge

    Science.gov (United States)

    Cumming, Stephen B.; Smith, Mark S.; Ali, Aliyah N.; Bui, Trong T.; Ellsworth, Joel C.; Garcia, Christian A.

    2016-01-01

    The aerodynamic effects of compliant flaps installed onto a modified Gulfstream III airplane were investigated. Analyses were performed prior to flight to predict the aerodynamic effects of the flap installation. Flight tests were conducted to gather both structural and aerodynamic data. The airplane was instrumented to collect vehicle aerodynamic data and wing pressure data. A leading-edge stagnation detection system was also installed. The data from these flights were analyzed and compared with predictions. The predictive tools compared well with flight data for small flap deflections, but differences between predictions and flight estimates were greater at larger deflections. This paper describes the methods used to examine the aerodynamics data from the flight tests and provides a discussion of the flight-test results in the areas of vehicle aerodynamics, wing sectional pressure coefficient profiles, and air data.

  16. A new reference tip-timing test bench and simulator for blade synchronous and asynchronous vibrations

    Science.gov (United States)

    Hajnayeb, Ali; Nikpour, Masood; Moradi, Shapour; Rossi, Gianluca

    2018-02-01

    The blade tip-timing (BTT) measurement technique is at present the most promising technique for monitoring the blades of axial turbines and aircraft engines in operating conditions. It is generally used as an alternative to strain gauges in turbine testing. By conducting a comparison with the standard methods such as those based on strain gauges, one determines that the technique is not intrusive and does not require a complicated installation process. Despite its superiority to other methods, the experimental performance analysis of a new BTT method needs a test stand that includes a reference measurement system (e.g. strain gauges equipped with telemetry or other complex optical measurement systems, like rotating laser Doppler vibrometers). In this article, a new reliable, low-cost BTT test setup is proposed for simulating and analyzing blade vibrations based on kinematic inversion. In the proposed test bench, instead of the blades vibrating, it is the BTT sensor that vibrates. The vibration of the sensor is generated by a shaker and can therefore be easily controlled in terms of frequency, amplitude and waveform shape. The amplitude of vibration excitation is measured by a simple accelerometer. After introducing the components of the simulator, the proposed test bench is used in practice to simulate both synchronous and asynchronous vibration scenarios. Then two BTT methods are used to evaluate the quality of the acquired data. The results demonstrate that the proposed setup is able to generate simulated pulse sequences which are almost the same as those generated by the conventional BTT systems installed around a bladed disk. Moreover, the test setup enables its users to evaluate BTT methods by using a limited number of sensors. This significantly reduces the total costs of the experiments.

  17. State-to-state time-of-flight measurements of NO scattering from Au(111): direct observation of translation-to-vibration coupling in electronically nonadiabatic energy transfer.

    Science.gov (United States)

    Golibrzuch, Kai; Shirhatti, Pranav R; Altschäffel, Jan; Rahinov, Igor; Auerbach, Daniel J; Wodtke, Alec M; Bartels, Christof

    2013-09-12

    Translational motion is believed to be a spectator degree of freedom in electronically nonadiabatic vibrational energy transfer between molecules and metal surfaces, but the experimental evidence available to support this view is limited. In this work, we have experimentally determined the translational inelasticity in collisions of NO molecules with a single-crystal Au(111) surface-a system with strong electronic nonadiabaticity. State-to-state molecular beam surface scattering was combined with an IR-UV double resonance scheme to obtain high-resolution time-of-flight data. The measurements include vibrationally elastic collisions (v = 3→3, 2→2) as well as collisions where one or two quanta of molecular vibration are excited (2→3, 2→4) or de-excited (2→1, 3→2, 3→1). In addition, we have carried out comprehensive measurements of the effects of rotational excitation on the translational energy of the scattered molecules. We find that under all conditions of this work, the NO molecules lose a large fraction (∼0.45) of their incidence translational energy to the surface. Those molecules that undergo vibrational excitation (relaxation) during the collision recoil slightly slower (faster) than vibrationally elastically scattered molecules. The amount of translational energy change depends on the surface temperature. The translation-to-rotation coupling, which is well-known for v = 0→0 collisions, is found to be significantly weaker for vibrationally inelastic than elastic channels. Our results clearly show that the spectator view of the translational motion in electronically nonadiabatic vibrational energy transfer between NO and Au(111) is only approximately correct.

  18. MATE: Modern Software Technology for Flight Test Automation and Orchestration, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of advanced technologies for flight testing, measurement, and data acquisition are critical to effectively meeting the future goals and challenges...

  19. An in situ test of vibrating wire stressmeters in granitic rock

    International Nuclear Information System (INIS)

    Spinney, M.H.

    1990-02-01

    An in situ test was conducted to assess the ability of vibrating-wire stressmeters to measure stress changes in hard, unfractured granitic rock at the Underground Research Laboratory (URL). Twelve vibrating-wire stressmeters installed ahead of the face and below floor grade of Room 205 were monitored during the excavation of Room 205. The results were compared with results from CSIRO hollow inclusion triaxial strain cells, USBM boreholes deformation gauge overcore tests done before and after excavation, and a two-dimensional numerical model

  20. The Shock and Vibration Bulletin. Part 3. Vibration Testing, Instrumentation and Data Analysis, Loads and Environments.

    Science.gov (United States)

    1977-09-01

    procedure previously described cannot be K’. 1,. , .L" - Initialize ..’.:_"....- _-’ __- array IRAN ( NLINE = number of . . Pseudo- spectral lines) IRAN(K...random---- Inumber " ..-. ’.: •.-.-. 1 , NACT ...-- T - • - - Convert to complex K 1 , NLINE and randot..ize the phase of each spectral line of the...sensitivity and calibration while installed in the test set-up. THE COMPONENTS OF THE SYSTEM.- There is available on the market , a photo- - diode which

  1. A Coupling Vibration Test Bench and the Simulation Research of a Maglev Vehicle

    Directory of Open Access Journals (Sweden)

    Weihua Ma

    2015-01-01

    Full Text Available To study the characteristics of the coupling vibration between a maglev vehicle and its track beam system and to improve the performance of the levitation system, a new type of vibration test bench was developed. Take a single maglev frame as the study object; simulation of the coupling vibration of the maglev vehicle, levitation system, and track beam were achieved. In addition, all types of real track irregularity excitations can be simulated using hydraulic actuators of the test bench. To expand the research scope, a simulation model was developed that can conduct the simulation research synergistically with the test bench. Based on a dynamics model of the test bench, the dynamics simulation method determined the influence on the levitation control performance of three factors: the track beam support stiffness, the track beam mass, and the track irregularity. The vibration resonance phenomenon of the vehicle/track system was reproduced by the dynamics simulation, and a portion of the simulation results were validated by the test results. By combining the test bench and the dynamics model, experiments can be guided by the simulation results, and the experimental results can validate the dynamics simulation results.

  2. Command and Data Handling Flight Software test framework: A Radiation Belt Storm Probes practice

    Science.gov (United States)

    Hill, T. A.; Reid, W. M.; Wortman, K. A.

    During the Radiation Belt Storm Probes (RBSP) mission, a test framework was developed by the Embedded Applications Group in the Space Department at the Johns Hopkins Applied Physics Laboratory (APL). The test framework is implemented for verification of the Command and Data Handling (C& DH) Flight Software. The RBSP C& DH Flight Software consists of applications developed for use with Goddard Space Flight Center's core Flight Executive (cFE) architecture. The test framework's initial concept originated with tests developed for verification of the Autonomy rules that execute with the Autonomy Engine application of the RBSP C& DH Flight Software. The test framework was adopted and expanded for system and requirements verification of the RBSP C& DH Flight Software. During the evolution of the RBSP C& DH Flight Software test framework design, a set of script conventions and a script library were developed. The script conventions and library eased integration of system and requirements verification tests into a comprehensive automated test suite. The comprehensive test suite is currently being used to verify releases of the RBSP C& DH Flight Software. In addition to providing the details and benefits of the test framework, the discussion will include several lessons learned throughout the verification process of RBSP C& DH Flight Software. Our next mission, Solar Probe Plus (SPP), will use the cFE architecture for the C& DH Flight Software. SPP also plans to use the same ground system as RBSP. Many of the RBSP C& DH Flight Software applications are reusable on the SPP mission, therefore there is potential for test design and test framework reuse for system and requirements verification.

  3. Hyper-X Mach 7 Scramjet Design, Ground Test and Flight Results

    Science.gov (United States)

    Ferlemann, Shelly M.; McClinton, Charles R.; Rock, Ken E.; Voland, Randy T.

    2005-01-01

    The successful Mach 7 flight test of the Hyper-X (X-43) research vehicle has provided the major, essential demonstration of the capability of the airframe integrated scramjet engine. This flight was a crucial first step toward realizing the potential for airbreathing hypersonic propulsion for application to space launch vehicles. However, it is not sufficient to have just achieved a successful flight. The more useful knowledge gained from the flight is how well the prediction methods matched the actual test results in order to have confidence that these methods can be applied to the design of other scramjet engines and powered vehicles. The propulsion predictions for the Mach 7 flight test were calculated using the computer code, SRGULL, with input from computational fluid dynamics (CFD) and wind tunnel tests. This paper will discuss the evolution of the Mach 7 Hyper-X engine, ground wind tunnel experiments, propulsion prediction methodology, flight results and validation of design methods.

  4. Fixed Base Modal Testing Using the NASA GRC Mechanical Vibration Facility

    Science.gov (United States)

    Staab, Lucas D.; Winkel, James P.; Suarez, Vicente J.; Jones, Trevor M.; Napolitano, Kevin L.

    2016-01-01

    The Space Power Facility at NASA's Plum Brook Station houses the world's largest and most powerful space environment simulation facilities, including the Mechanical Vibration Facility (MVF), which offers the world's highest-capacity multi-axis spacecraft shaker system. The MVF was designed to perform sine vibration testing of a Crew Exploration Vehicle (CEV)-class spacecraft with a total mass of 75,000 pounds, center of gravity (cg) height above the table of 284 inches, diameter of 18 feet, and capability of 1.25 gravity units peak acceleration in the vertical and 1.0 gravity units peak acceleration in the lateral directions. The MVF is a six-degree-of-freedom, servo-hydraulic, sinusoidal base-shake vibration system that has the advantage of being able to perform single-axis sine vibration testing of large structures in the vertical and two lateral axes without the need to reconfigure the test article for each axis. This paper discusses efforts to extend the MVF's capabilities so that it can also be used to determine fixed base modes of its test article without the need for an expensive test-correlated facility simulation.

  5. NASA Langley's AirSTAR Testbed: A Subscale Flight Test Capability for Flight Dynamics and Control System Experiments

    Science.gov (United States)

    Jordan, Thomas L.; Bailey, Roger M.

    2008-01-01

    As part of the Airborne Subscale Transport Aircraft Research (AirSTAR) project, NASA Langley Research Center (LaRC) has developed a subscaled flying testbed in order to conduct research experiments in support of the goals of NASA s Aviation Safety Program. This research capability consists of three distinct components. The first of these is the research aircraft, of which there are several in the AirSTAR stable. These aircraft range from a dynamically-scaled, twin turbine vehicle to a propeller driven, off-the-shelf airframe. Each of these airframes carves out its own niche in the research test program. All of the airplanes have sophisticated on-board data acquisition and actuation systems, recording, telemetering, processing, and/or receiving data from research control systems. The second piece of the testbed is the ground facilities, which encompass the hardware and software infrastructure necessary to provide comprehensive support services for conducting flight research using the subscale aircraft, including: subsystem development, integrated testing, remote piloting of the subscale aircraft, telemetry processing, experimental flight control law implementation and evaluation, flight simulation, data recording/archiving, and communications. The ground facilities are comprised of two major components: (1) The Base Research Station (BRS), a LaRC laboratory facility for system development, testing and data analysis, and (2) The Mobile Operations Station (MOS), a self-contained, motorized vehicle serving as a mobile research command/operations center, functionally equivalent to the BRS, capable of deployment to remote sites for supporting flight tests. The third piece of the testbed is the test facility itself. Research flights carried out by the AirSTAR team are conducted at NASA Wallops Flight Facility (WFF) on the Eastern Shore of Virginia. The UAV Island runway is a 50 x 1500 paved runway that lies within restricted airspace at Wallops Flight Facility. The

  6. CFD to Flight: Some Recent Success Stories of X-Plane Design to Flight Test at the NASA Dryden Flight Research Center

    Science.gov (United States)

    Cosentino, Gary B.

    2007-01-01

    Several examples from the past decade of success stories involving the design and flight test of three true X-planes will be described: in particular, X-plane design techniques that relied heavily upon computational fluid dynamics (CFD). Three specific examples chosen from the author s personal experience are presented: the X-36 Tailless Fighter Agility Research Aircraft, the X-45A Unmanned Combat Air Vehicle, and, most recently, the X-48B Blended Wing Body Demonstrator Aircraft. An overview will be presented of the uses of CFD analysis, comparisons and contrasts with wind tunnel testing, and information derived from the CFD analysis that directly related to successful flight test. Some lessons learned on the proper application, and misapplication, of CFD are illustrated. Finally, some highlights of the flight-test results of the three example X-planes will be presented. This overview paper will discuss some of the author s experience with taking an aircraft shape from early concept and three-dimensional modeling through CFD analysis, wind tunnel testing, further refined CFD analysis, and, finally, flight. An overview of the key roles in which CFD plays well during this process, and some other roles in which it does not, are discussed. How wind tunnel testing complements, calibrates, and verifies CFD analysis is also covered. Lessons learned on where CFD results can be misleading are also given. Strengths and weaknesses of the various types of flow solvers, including panel methods, Euler, and Navier-Stokes techniques, are discussed. The paper concludes with the three specific examples, including some flight test video footage of the X-36, the X-45A, and the X-48B.

  7. The X-43A Hyper-X Mach 7 Flight 2 Guidance, Navigation, and Control Overview and Flight Test Results

    Science.gov (United States)

    Bahm, Catherine; Baumann, Ethan; Martin, John; Bose, David; Beck, Roger E.; Strovers, Brian

    2005-01-01

    The objective of the Hyper-X program was to flight demonstrate an airframe-integrated hypersonic vehicle. On March 27, 2004, the Hyper-X program team successfully conducted flight 2 and achieved all of the research objectives. The Hyper-X research vehicle successfully separated from the Hyper-X launch vehicle and achieved the desired engine test conditions before the experiment began. The research vehicle rejected the disturbances caused by the cowl door opening and the fuel turning on and off and maintained the engine test conditions throughout the experiment. After the engine test was complete, the vehicle recovered and descended along a trajectory while performing research maneuvers. The last data acquired showed that the vehicle maintained control to the water. This report will provide an overview of the research vehicle guidance and control systems and the performance of the vehicle during the separation event and engine test. The research maneuvers were performed to collect data for aerodynamics and flight controls research. This report also will provide an overview of the flight controls related research and results.

  8. Verification of hybrid analysis concept of soil-foundation interaction by field vibration tests. Pt. 2

    International Nuclear Information System (INIS)

    Katayama, I.; Niwa, A.; Kubo, Y.; Penzien, J.

    1987-01-01

    The paper describes the outline of the hybrid analysis code for soil-structure interaction (HASSI) and the results of numerical simulation of the responses obtained at the model 2C in both cases of the forced vibration test and the natural earthquake excitation. (orig./HP)

  9. Lumped Parameter Modeling for Rapid Vibration Response Prototyping and Test Correlation for Electronic Units

    Science.gov (United States)

    Van Dyke, Michael B.

    2013-01-01

    Present preliminary work using lumped parameter models to approximate dynamic response of electronic units to random vibration; Derive a general N-DOF model for application to electronic units; Illustrate parametric influence of model parameters; Implication of coupled dynamics for unit/board design; Demonstrate use of model to infer printed wiring board (PWB) dynamics from external chassis test measurement.

  10. Vibration test on KMRR reactor structure and primary cooling system piping

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Seung Hoh; Kim, Tae Ryong; Park, Jin Hoh; Park, Jin Suk; Ryoo, Jung Soo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-10-01

    Most equipments, piping systems and reactor structures in nuclear power plants are subjected to flow induced vibration due to high temperature and high pressure coolant flowing inside or outside of the equipments, systems and structures. Because the flow induced vibration sometimes causes significant damage to reactor structures and piping systems, it is important and necessary to evaluate the vibration effect on them and to prove their structural integrity. Korea Multipurpose Research Reactor (KMRR) being constructed by KAERI is 30 MWt pool type research reactor. Since its main structures and piping systems were designed and manufactured in accordance with the standards and guidelines for commercial nuclear power plant, it was decided to evaluate their vibratory response in accordance with the standards and guidelines for commercial NPP. The objective of this vibration test is the assessment of vibration levels of KMRR reactor structure and primary cooling piping system for their structural integrity under the steady-state or transient operating condition. 38 figs, 14 tabs, 2 refs. (Author).

  11. Vibration test on KMRR reactor structure and primary cooling system piping

    International Nuclear Information System (INIS)

    Chung, Seung Hoh; Kim, Tae Ryong; Park, Jin Hoh; Park, Jin Suk; Ryoo, Jung Soo

    1994-10-01

    Most equipments, piping systems and reactor structures in nuclear power plants are subjected to flow induced vibration due to high temperature and high pressure coolant flowing inside or outside of the equipments, systems and structures. Because the flow induced vibration sometimes causes significant damage to reactor structures and piping systems, it is important and necessary to evaluate the vibration effect on them and to prove their structural integrity. Korea Multipurpose Research Reactor (KMRR) being constructed by KAERI is 30 MWt pool type research reactor. Since its main structures and piping systems were designed and manufactured in accordance with the standards and guidelines for commercial nuclear power plant, it was decided to evaluate their vibratory response in accordance with the standards and guidelines for commercial NPP. The objective of this vibration test is the assessment of vibration levels of KMRR reactor structure and primary cooling piping system for their structural integrity under the steady-state or transient operating condition. 38 figs, 14 tabs, 2 refs. (Author)

  12. Numerical CFD Simulation and Test Correlation in a Flight Project Environment

    Science.gov (United States)

    Gupta, K. K.; Lung, S. F.; Ibrahim, A. H.

    2015-01-01

    This paper presents detailed description of a novel CFD procedure and comparison of its solution results to that obtained by other available CFD codes as well as actual flight and wind tunnel test data pertaining to the GIII aircraft, currently undergoing flight testing at AFRC.

  13. Frontside-micromachined planar piezoresistive vibration sensor: Evaluating performance in the low frequency test range

    Directory of Open Access Journals (Sweden)

    Lan Zhang

    2014-01-01

    Full Text Available Using a surface piezoresistor diffusion method and front-side only micromachining process, a planar piezoresistive vibration sensor was successfully developed with a simple structure, lower processing cost and fewer packaging difficulties. The vibration sensor had a large sector proof mass attached to a narrow flexure. Optimization of the boron diffusion piezoresistor placed on the edge of the narrow flexure greatly improved the sensitivity. Planar vibration sensors were fabricated and measured in order to analyze the effects of the sensor dimensions on performance, including the values of flexure width and the included angle of the sector. Sensitivities of fabricated planar sensors of 0.09–0.46 mV/V/g were measured up to a test frequency of 60 Hz. The sensor functioned at low voltages (<3 V and currents (<1 mA with a high sensitivity and low drift. At low background noise levels, the sensor had performance comparable to a commercial device.

  14. Frontside-micromachined planar piezoresistive vibration sensor: Evaluating performance in the low frequency test range

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lan; Lu, Jian, E-mail: jian-lu@aist.go.jp; Takagi, Hideki; Maeda, Ryutaro [Research Center for Ubiquitous MEMS and Micro Engineering (UMEMSME), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8564 (Japan)

    2014-01-15

    Using a surface piezoresistor diffusion method and front-side only micromachining process, a planar piezoresistive vibration sensor was successfully developed with a simple structure, lower processing cost and fewer packaging difficulties. The vibration sensor had a large sector proof mass attached to a narrow flexure. Optimization of the boron diffusion piezoresistor placed on the edge of the narrow flexure greatly improved the sensitivity. Planar vibration sensors were fabricated and measured in order to analyze the effects of the sensor dimensions on performance, including the values of flexure width and the included angle of the sector. Sensitivities of fabricated planar sensors of 0.09–0.46 mV/V/g were measured up to a test frequency of 60 Hz. The sensor functioned at low voltages (<3 V) and currents (<1 mA) with a high sensitivity and low drift. At low background noise levels, the sensor had performance comparable to a commercial device.

  15. Piecewise Polynomial Fitting with Trend Item Removal and Its Application in a Cab Vibration Test

    Directory of Open Access Journals (Sweden)

    Wu Ren

    2018-01-01

    Full Text Available The trend item of a long-term vibration signal is difficult to remove. This paper proposes a piecewise integration method to remove trend items. Examples of direct integration without trend item removal, global integration after piecewise polynomial fitting with trend item removal, and direct integration after piecewise polynomial fitting with trend item removal were simulated. The results showed that direct integration of the fitted piecewise polynomial provided greater acceleration and displacement precision than the other two integration methods. A vibration test was then performed on a special equipment cab. The results indicated that direct integration by piecewise polynomial fitting with trend item removal was highly consistent with the measured signal data. However, the direct integration method without trend item removal resulted in signal distortion. The proposed method can help with frequency domain analysis of vibration signals and modal parameter identification for such equipment.

  16. Vibration tests on some models of PEC reactor core elements

    International Nuclear Information System (INIS)

    Bonacina, G.; Castoldi, A.; Zola, M.; Cecchini, F.; Martelli, A.; Vincenzi, D.

    1982-01-01

    This paper describes the aims of the experimental tests carried out at ISMES, within an agreement with the Department of Fast Reactors of ENEA, on some models of the elements of PEC Fast Nuclear Reactor Core in the frame of the activities for the seismic verification of the PEC core. The seismic verification is briefly described with particular attention to the problems arising from the shocks among the various elements during an earthquake, as well as the computer code used, the purpose and the techniques used to perform tests, some results and the first comparison between the theory and the experimental data

  17. Advanced fighter technology integration (AFTI)/F-16 Automated Maneuvering Attack System final flight test results

    Science.gov (United States)

    Dowden, Donald J.; Bessette, Denis E.

    1987-01-01

    The AFTI F-16 Automated Maneuvering Attack System has undergone developmental and demonstration flight testing over a total of 347.3 flying hours in 237 sorties. The emphasis of this phase of the flight test program was on the development of automated guidance and control systems for air-to-air and air-to-ground weapons delivery, using a digital flight control system, dual avionics multiplex buses, an advanced FLIR sensor with laser ranger, integrated flight/fire-control software, advanced cockpit display and controls, and modified core Multinational Stage Improvement Program avionics.

  18. A new method for flight test determination of propulsive efficiency and drag coefficient

    Science.gov (United States)

    Bull, G.; Bridges, P. D.

    1983-01-01

    A flight test method is described from which propulsive efficiency as well as parasite and induced drag coefficients can be directly determined using relatively simple instrumentation and analysis techniques. The method uses information contained in the transient response in airspeed for a small power change in level flight in addition to the usual measurement of power required for level flight. Measurements of pitch angle and longitudinal and normal acceleration are eliminated. The theoretical basis for the method, the analytical techniques used, and the results of application of the method to flight test data are presented.

  19. Performance studies of the vibration wire monitor on the test stand with low energy electron beam

    International Nuclear Information System (INIS)

    Okabe, Kota; Yoshimoto, Masahiro; Kinsho, Michikazu

    2015-01-01

    In the high intensity proton accelerator as the Japan Proton Accelerator Research Complex (J-PARC) accelerators, serious radiation and residual dose is induced by a small beam loss such a beam halo. Therefore, diagnostics of the beam halo formation is one of the most important issues to control the beam loss. For the beam halo monitor, the vibration wire monitor (VWM) has a potential for investigating the beam halo and weak beam scanning. The VWM has a wide dynamic range, high resolution and the VWM is not susceptible to secondary electrons and electric noises. We have studied the VWM features as a new beam-halo monitor on the test stand with low energy electron gun. The frequency shift of the irradiated vibration wire was confirmed about wire material and the electron beam profile measured by using the VWM was consistent with the results of the Faraday cup measurement. Also we calculated a temperature distribution on the vibration wire which is irradiated by the electron beam with the numerical simulation. The simulations have been fairly successful in reproducing the transient of the irradiated vibration wire frequency measured by test stand experiments. In this paper, we will report a result of performance evaluation for the VWM on the test stands and discuss the VWM for beam halo diagnostic. (author)

  20. Design of Accelerated Reliability Test for CNC Motorized Spindle Based on Vibration Signal

    Directory of Open Access Journals (Sweden)

    Chen Chao

    2016-01-01

    Full Text Available Motorized spindle is the key functional component of CNC machining centers which is a mechatronics system with long life and high reliability. The reliability test cycle of motorized spindle is too long and infeasible. This paper proposes a new accelerated test for reliability evaluation of motorized spindle. By field reliability test, authors collect and calculate the load data including rotational speed, cutting force and torque. Load spectrum distribution law is analyzed. And authors design a test platform to apply the load spectrum. A new method to define the fuzzy acceleration factor based on the vibration signal is proposed. Then the whole test plan of accelerated reliability test is done.

  1. Post Flight Analysis Of SHEFEX I: Shock Tunnel Testing And Related CFD Analysis

    Science.gov (United States)

    Schramm, Jan Martinez; Barth, Tarik; Wagner, Alexander; Hannemann, Klaus

    2011-05-01

    The SHarp Edge Flight EXperiment (SHEFEX) program of the German Aerospace Center (DLR) is primarily focused on the investigation of the potential to utilise improved shapes for space vehicles by considering sharp edges and facetted surfaces. One goal is to set up a sky based test facility to gain knowledge of the physics of hypersonic flow, complemented by numerical analysis and ground based testing. Further, the series of SHEFEX flight experiments is an excellent test bed for new technological concepts and flight instrumentation, and it is a source of motivation for young scientist and engineers providing an excellent school for future space-program engineers and managers. After the successful first SHEFEX flight in October 2005, a second flight is scheduled for September 2011 and additional flights are planned for 2015 ff. With the SHEFEX-I flight and the subsequent numerical and experimental post flight analysis, DLR could for the first time close the loop between the three major disciplines of aerothermodynamic research namely CFD, ground based testing and flight.

  2. Procedure for vibration test of the fuel rod supported by spacer grids

    International Nuclear Information System (INIS)

    Choi, Myoung Hwan; Kang, Heung Seok; Yoon, Kyung Ho; Kim, Hyung Kyu; Song, Kee Nam

    2002-07-01

    One of the methods that are used to compare and verify the supporting performance of the spacer grids developed is the vibration characteristic test. In this report there are two aims. One is of the understand of the experimental method and procedure performing the modal testing using I-DEAS TDAS module. The other is the investigation of the vibration behaviors of a dummy fuel rod supported by 8 optimized H type spacer grids. This report describes the method and procedure of modal testing to obtain the vibration characteristics such as amplitudes, natural frequencies and mode shapes of the fuel rod using a shaker, a non-contact gap sensor and an accelerometer. This report provides a test procedure in detail so that anyone can be easily understood and use the I-DEAS TDAS program. The I-DEAS TDAS program related to the modal testing has several tasks including the Modal analysis, Signal Processing et al.. This report includes model preparation to prepare the geometrical model, Signal Processing (Sine/Standard measurement) to acquire the signal, Modal analysis to obtain the frequencies and mode shapes, Correlation to analyze the relation between the test and FE analysis and Post Processing tasks. In addition, this report contains the actual test and analysis data of a dummy fuel rod in length 3847mm supported by 8 optimized H type spacer grids

  3. Vibration tests on pile-group foundations using large-scale blast excitation

    International Nuclear Information System (INIS)

    Tanaka, Hideo; Hijikata, Katsuichirou; Hashimoto, Takayuki; Fujiwara, Kazushige; Kontani, Osamu; Miyamoto, Yuji; Suzuki, Atsushi

    2005-01-01

    Extensive vibration tests have been performed on pile-supported structures at a large-scale mining site. Ground motions induced by large-scale blasting operations were used as excitation forces for vibration tests. The main objective of this research is to investigate the dynamic behavior of pile-supported structures, in particular, pile-group effects. Two test structures were constructed in an excavated 4 m deep pit. One structure had 25 steel tubular piles and the other had 4 piles. The super-structures were exactly the same. The test pit was backfilled with sand of appropriate grain size distributions in order to obtain good compaction, especially between the 25 piles. Accelerations were measured at the structures, in the test pit and in the adjacent free field, and pile strains were measured. The vibration tests were performed six times with different levels of input motions. The maximum horizontal acceleration recorded at the adjacent ground surface varied from 57 cm/s 2 to 1683 cm/s 2 according to the distances between the test site and the blast areas. Maximum strains were 13,400 micro-strains were recorded at the pile top of the 4-pile structure, which means that these piles were subjected to yielding

  4. Diagnostic tests in Raynaud's phenomena in workers exposed to vibration: a comparative study

    DEFF Research Database (Denmark)

    Olsen, N

    1988-01-01

    Four objective tests to evaluate Raynaud's phenomena (RP) in workers exposed to handarm vibrations were applied on 23 exposed men with RP (vibration induced white finger 18, primary Raynaud's phenomenon 5), 56 exposed men without RP, and 15 male controls. Finger systolic blood pressure was measured...... greater than 0.20). The results indicate that a finger colour test may be as valuable as a FSP(0) test for diagnostic purposes. FSP(A) only indicates if a cold response is exaggerated and does not diagnose RP. The pressure measurements may further be of guidance in evaluating preventive measures...... by a cuff and strain gauge technique after combined body cooling and finger cooling during five minute ischaemia to 30 degrees, 15 degrees, and 6 degrees C. An attack of RP was detected as a zero pressure, FSP(0) test, whereas a pressure, reduced to a value below the normal 95% confidence limit at 6 degrees...

  5. Minute Impurities Contribute Significantly to Olfactory Receptor Ligand Studies: Tales from Testing the Vibration Theory

    OpenAIRE

    Paoli, M.; M?nch, D.; Haase, A.; Skoulakis, E.; Turin, L.; Galizia, C. G.

    2017-01-01

    Several studies have attempted to test the vibrational hypothesis of odorant receptor activation in behavioral and physiological studies using deuterated compounds as odorants. The results have been mixed. Here, we attempted to test how deuterated compounds activate odorant receptors using calcium imaging of the fruit fly antennal lobe. We found specific activation of one area of the antennal lobe corresponding to inputs from a specific receptor. However, upon more detailed analysis, we disco...

  6. Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Laboratory

    Science.gov (United States)

    Brewster, L.; Johnston, A.; Howard, R.; Mitchell, J.; Cryan, S.

    2007-01-01

    The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success of the Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-loop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of"pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL

  7. Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Lab

    Science.gov (United States)

    Brewster, Linda L.; Howard, Richard T.; Johnston, A. S.; Carrington, Connie; Mitchell, Jennifer D.; Cryan, Scott P.

    2008-01-01

    The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success ofthe Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor-proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-Ioop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of "pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL

  8. Mission definition study for Stanford relativity satellite. Volume 2: Engineering flight test program

    Science.gov (United States)

    1971-01-01

    The need is examined for orbital flight tests of gyroscope, dewar, and other components, in order to reduce the technical and financial risk in performing the relativity experiment. A program is described that would generate engineering data to permit prediction of final performance. Two flight tests are recommended. The first flight would test a dewar smaller than that required for the final flight, but of size and form sufficient to allow extrapolation to the final design. The second flight would use the same dewar design to carry a set of three gyroscopes, which would be evaluated for spinup and drift characteristics for a period of a month or more. A proportional gas control system using boiloff helium gas from the dewar, and having the ability to prevent sloshing of liquid helium, would also be tested.

  9. Flight Tests of a Ministick Controller in an F/A-18 Airplane

    Science.gov (United States)

    Stoliker, Patrick C.; Carter, John

    2003-01-01

    In March of 1999, five pilots performed flight tests to evaluate the handling qualities of an F/A-18 research airplane equipped with a small-displacement center stick (ministick) controller that had been developed for the JAS 39 Gripen airplane (a fighter/attack/ reconnaissance airplane used by the Swedish air force). For these tests, the ministick was installed in the aft cockpit (see figure) and production support flight control computers (PSFCCs) were used as interfaces between the controller hardware and the standard F/A-18 flight-control laws. The primary objective of the flight tests was to assess any changes in handling qualities of the F/A-18 airplane attributable to the mechanical characteristics of the ministick. The secondary objective was to demonstrate the capability of the PSFCCs to support flight-test experiments.

  10. Ares I-X Flight Test Validation of Control Design Tools in the Frequency-Domain

    Science.gov (United States)

    Johnson, Matthew; Hannan, Mike; Brandon, Jay; Derry, Stephen

    2011-01-01

    A major motivation of the Ares I-X flight test program was to Design for Data, in order to maximize the usefulness of the data recorded in support of Ares I modeling and validation of design and analysis tools. The Design for Data effort was intended to enable good post-flight characterizations of the flight control system, the vehicle structural dynamics, and also the aerodynamic characteristics of the vehicle. To extract the necessary data from the system during flight, a set of small predetermined Programmed Test Inputs (PTIs) was injected directly into the TVC signal. These PTIs were designed to excite the necessary vehicle dynamics while exhibiting a minimal impact on loads. The method is similar to common approaches in aircraft flight test programs, but with unique launch vehicle challenges due to rapidly changing states, short duration of flight, a tight flight envelope, and an inability to repeat any test. This paper documents the validation effort of the stability analysis tools to the flight data which was performed by comparing the post-flight calculated frequency response of the vehicle to the frequency response calculated by the stability analysis tools used to design and analyze the preflight models during the control design effort. The comparison between flight day frequency response and stability tool analysis for flight of the simulated vehicle shows good agreement and provides a high level of confidence in the stability analysis tools for use in any future program. This is true for both a nominal model as well as for dispersed analysis, which shows that the flight day frequency response is enveloped by the vehicle s preflight uncertainty models.

  11. Hand-arm vibration syndrome: clinical characteristics, conventional electrophysiology and quantitative sensory testing.

    Science.gov (United States)

    Rolke, Roman; Rolke, Silke; Vogt, Thomas; Birklein, Frank; Geber, Christian; Treede, Rolf-Detlef; Letzel, Stephan; Voelter-Mahlknecht, Susanne

    2013-08-01

    Workers exposed to vibrating tools may develop hand-arm vibration syndrome (HAVS). We assessed the somatosensory phenotype using quantitative sensory testing (QST) in comparison to electrophysiology to characterize (1) the most sensitive QST parameter for detecting sensory loss, (2) the correlation of QST and electrophysiology, and (3) the frequency of a carpal tunnel syndrome (CTS) in HAVS. QST, cold provocation tests, fine motor skills, and median nerve neurography were used. QST included thermal and mechanical detection and pain thresholds. Thirty-two patients were examined (54 ± 11 years, 91% men) at the more affected hand compared to 16 matched controls. Vibration detection threshold was the most sensitive parameter to detect sensory loss that was more pronounced in the sensitivity range of Pacinian (150 Hz, x12) than Meissner's corpuscles (20 Hz, x3). QST (84% abnormal) was more sensitive to detect neural dysfunction than conventional electrophysiology (37% abnormal). Motor (34%) and sensory neurography (25%) were abnormal in HAVS. CTS frequency was not increased (9.4%). Findings are consistent with a mechanically-induced, distally pronounced motor and sensory neuropathy independent of CTS. HAVS involves a neuropathy predominantly affecting large fibers with a sensory damage related to resonance frequencies of vibrating tools. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  12. One stacked-column vibration test and analysis for VHTR core

    International Nuclear Information System (INIS)

    Ikushima, Takeshi; Ishizuka, Hiroshi; Ide, Akira; Hayakawa, Hitoshi; Shingai, Kazuteru.

    1978-07-01

    This paper describes experimental results of the vibration test on a single stacked-column and compares them with the analytical results. A 1/2 scale model of the core element of a very high temperature gas-cooled reactor (VHTR) was set on a shaking table. Sinusoidal waves, response time history waves, beat wave and step wave of input acceleration 100 - 900 gal in the frequency of 0.5 to 15 Hz were used to vibrate the table horizontally. Results are as follows: (1) The column has a non-linear resonance and exhibits a hysteresis response with jump points. (2) The column vibration characteristics is similar to that of the finite beams connected with non-linear soft spring. (3) The column resonance frequency decreases with increasing input acceleration. (4) The impact force increases with increasing input acceleration and boundary gap width. (5) Good correlation in vibration behavior of the stacked-column and impact force on the boundary between test and analysis was obtained. (auth.)

  13. Improvement of the vibration of the test fuel(Type-B) with a guide tube under operational condition

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Dong Seung; Yim, Jeong Sik; Lim, I. C. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-04-01

    The Type-B test fuel for the Hanaro has a flexible guide tube on top of the fuel to lead and guide the instrumentation wires. Depending on the flow condition in the reactor, the fuel is susceptible to vibration. During the test operation of the fuel, a fairly large amplitude vibration was observed and the possibility of flow tube contact with adjacent flow tubes, due to the excessive vibration of the fuel, and consequent wear or defect of the flow tubes were raised. Thus, to know the vibration characteristics as well as whether the flow tube contact each other, analyses of the Type-B fuel the dummy fuel were performed by BEVIRA and ANSYS. Besides the analyses, vibration tests using the dummy fuel in air and with Type-B fuel in the core at zero power under operational flow condition were executed. The results from the analyses were compared with those from tests to validate the analyses. From the deflection test of the dummy fuel in air to get the maximum displacement of the flow tube at the top, the flow tube were found to contact each other. For the prevention of the contact of the flow tubes caused by the excessive vibration of the guide tube, an additional support to the guide tube was proposed. With the additional support, analysis and in core vibration test under operational flow condition were conducted and there found to be no excessive vibration any more. 6 refs., 16 figs., 6 tabs. (Author)

  14. CR-Calculus and adaptive array theory applied to MIMO random vibration control tests

    Science.gov (United States)

    Musella, U.; Manzato, S.; Peeters, B.; Guillaume, P.

    2016-09-01

    Performing Multiple-Input Multiple-Output (MIMO) tests to reproduce the vibration environment in a user-defined number of control points of a unit under test is necessary in applications where a realistic environment replication has to be achieved. MIMO tests require vibration control strategies to calculate the required drive signal vector that gives an acceptable replication of the target. This target is a (complex) vector with magnitude and phase information at the control points for MIMO Sine Control tests while in MIMO Random Control tests, in the most general case, the target is a complete spectral density matrix. The idea behind this work is to tailor a MIMO random vibration control approach that can be generalized to other MIMO tests, e.g. MIMO Sine and MIMO Time Waveform Replication. In this work the approach is to use gradient-based procedures over the complex space, applying the so called CR-Calculus and the adaptive array theory. With this approach it is possible to better control the process performances allowing the step-by-step Jacobian Matrix update. The theoretical bases behind the work are followed by an application of the developed method to a two-exciter two-axis system and by performance comparisons with standard methods.

  15. Flight test techniques for validating simulated nuclear electromagnetic pulse aircraft responses

    Science.gov (United States)

    Winebarger, R. M.; Neely, W. R., Jr.

    1984-01-01

    An attempt has been made to determine the effects of nuclear EM pulses (NEMPs) on aircraft systems, using a highly instrumented NASA F-106B to document the simulated NEMP environment at the Kirtland Air Force Base's Vertically Polarized Dipole test facility. Several test positions were selected so that aircraft orientation relative to the test facility would be the same in flight as when on the stationary dielectric stand, in order to validate the dielectric stand's use in flight configuration simulations. Attention is given to the flight test portions of the documentation program.

  16. Design of Hydraulic Bushing and Vehicle Testing for Reducing the Judder Vibration

    Directory of Open Access Journals (Sweden)

    Kim Youngman

    2018-01-01

    Full Text Available Generally, judder vibration is a low-frequency vibration phenomenon caused by a braking force imbalance that occurs when a vehicle is lightly decelerated within a range of 0.1 to 0.2g at a speed of 120 to 60 km/h. This comes from the change in the brake disk thickness (DTV, which is mainly caused by the side run-out (SRO and thermal deformation. The adoption of hydro-bushing in the low arm G bushings of the vehicle front suspension has been done in order to provide great damping in a particular frequency range (<20Hz in order to prevent this judder vibration from being transmitted to the body. The hydro bushing was formulated using a lumped parameter model. The fluid passage between the two chambers was modelled as a nonlinear element such as an orifice, and its important parameters (resistance, compliance were measured using a simplified experimental setup. The main design parameters are the ratio of the cross-sectional area of the chamber to the fluid passage, the length of the fluid passage, etc., and their optimal design is such that the loss angle is greater than 45 ° in the target frequency range of 10 to 20 Hz. The hydro bushing designed for reducing the judder vibration was prepared for the actual vehicle application test and applied to the actual vehicle test. In this study, the proposed hydro bushing was applied to the G bushing of the low arm of the front suspension system of the vehicle. The loss angle of the manufactured hydro bushing was measured using acceleration signals before and after passing through the bushing. The actual vehicle test was performed on the noise dynamometer for the performance analysis of the judder vibration reduction.

  17. Pre-flight physical simulation test of HIMES reentry test vehicle

    Science.gov (United States)

    Kawaguchi, Jun'ichiro; Inatani, Yoshifumi; Yonemoto, Koichi; Hosokawa, Shigeru

    ISAS is now developing a small reentry test vehicle, which is 2m long with a 1.5m wing span and weighs about 170 kg, for the purpose of exploring high angle-of-attack aerodynamic attitude control issue in supersonic and hypersonic speed. The flight test, employing 'Rockoon' launch system, is planned as a preliminary design verification for a fully reusable winged rocket named HIMES (Highly Maneuverable Experimental Space) vehicle. This paper describes the results of preflight ground test using a motion table system. This ground system test is called 'physical simulation' aimed at: (1) functional verification of side-jet system, aerodynamic surface actuators, battery and onboard avionics; and (2) guidance and control law evaluation, in total hardware-in-the-loop system. The pressure of side-jet nozzles was measured to provide exact thrust characteristics of reaction control. The dynamics of vehicle motion was calculated in real-time by the ground simulation computer.

  18. Synthetic and Enhanced Vision Systems for NextGen (SEVS) Simulation and Flight Test Performance Evaluation

    Science.gov (United States)

    Shelton, Kevin J.; Kramer, Lynda J.; Ellis,Kyle K.; Rehfeld, Sherri A.

    2012-01-01

    The Synthetic and Enhanced Vision Systems for NextGen (SEVS) simulation and flight tests are jointly sponsored by NASA's Aviation Safety Program, Vehicle Systems Safety Technology project and the Federal Aviation Administration (FAA). The flight tests were conducted by a team of Honeywell, Gulfstream Aerospace Corporation and NASA personnel with the goal of obtaining pilot-in-the-loop test data for flight validation, verification, and demonstration of selected SEVS operational and system-level performance capabilities. Nine test flights (38 flight hours) were conducted over the summer and fall of 2011. The evaluations were flown in Gulfstream.s G450 flight test aircraft outfitted with the SEVS technology under very low visibility instrument meteorological conditions. Evaluation pilots flew 108 approaches in low visibility weather conditions (600 ft to 2400 ft visibility) into various airports from Louisiana to Maine. In-situ flight performance and subjective workload and acceptability data were collected in collaboration with ground simulation studies at LaRC.s Research Flight Deck simulator.

  19. Evaluation of the Impact Resistance of Various Composite Sandwich Beams by Vibration Tests

    Directory of Open Access Journals (Sweden)

    Amir Shahdin

    2011-01-01

    Full Text Available Impact resistance of different types of composite sandwich beams is evaluated by studying vibration response changes (natural frequency and damping ratio. This experimental works will help aerospace structural engineer in assess structural integrity using classification of impact resistance of various composite sandwich beams (entangled carbon and glass fibers, honeycomb and foam cores. Low velocity impacts are done below the barely visible impact damage (BVID limit in order to detect damage by vibration testing that is hardly visible on the surface. Experimental tests are done using both burst random and sine dwell testing in order to have a better confidence level on the extracted modal parameters. Results show that the entangled sandwich beams have a better resistance against impact as compared to classical core materials.

  20. The development of sine vibration test requirements for Viking lander capsule components

    Science.gov (United States)

    Barrett, S.

    1974-01-01

    In connection with the Viking project for exploring the planet Mars, two identical spacecraft, each consisting of an orbiter and a lander, will be launched in the third quarter of 1975. Upon arrival at the planet, the Viking lander will separate from the Viking orbiter and descend to a soft landing at a selected site on the Mars surface. It was decided to perform a sine vibration test on the Viking spacecraft, in its launch configuration, to qualify it for the booster-induced transient-dynamic environment. It is shown that component-level testing is a cost- and schedule-effective prerequisite to the system-level, sine-vibration test sequences.

  1. Sensor design for outdoor racing bicycle field testing for human vibration comfort evaluation

    International Nuclear Information System (INIS)

    Vanwalleghem, Joachim; De Baere, Ives; Van Paepegem, Wim; Loccufier, Mia

    2013-01-01

    This paper is concerned with the vibrational comfort evaluation of the cyclist when cycling a rough surface. Outdoor comfort tests have so far only been done through instrumenting the bicycle with accelerometers. This work instruments a racing bicycle with custom-made contact force sensors and velocity sensors to acquire human comfort through the absorbed power method. Comfort evaluation is assessed at the hand–arm and seat interface of the cyclist with the bicycle. By means of careful finite-element analysis for designing the force gauges at the handlebar and the seat combined with precise calibration of both force and velocity sensors, all sensors have proven to work properly. Initial field tests are focused on the proper functioning of the designed sensors and their suitability for vibration comfort measurements. Tests on a cobblestone road reveal that the outcome of the absorbed power values is within the same range as those from laboratory tests found in the literature. This sensor design approach for outdoor testing with racing bicycles may give a new interpretation on evaluating the cyclist's comfort since the vibrational load is not only quantified in terms of acceleration but also in terms of force and velocity at the bicycle–cyclist contact points. (paper)

  2. Flight Test Results from the Rake Airflow Gage Experiment on the F-15B Airplane

    Science.gov (United States)

    Frederick, Michael A.; Ratnayake, Nalin A.

    2011-01-01

    The Rake Airflow Gage Experiment involves a flow-field survey rake that was flown on the Propulsion Flight Test Fixture at the NASA Dryden Flight Research Center using the Dryden F-15B research test bed airplane. The objective of this flight test was to ascertain the flow-field angularity, local Mach number profile, total pressure distortion, and dynamic pressure at the aerodynamic interface plane of the Channeled Centerbody Inlet Experiment. This new mixed-compression, supersonic inlet is planned for flight test in the near term. Knowledge of the flow-field characteristics at this location underneath the airplane is essential to flight test planning and computational modeling of the new inlet, anairplane, flying at a free-stream Mach number of 1.65 and a pressure altitude of 40,000 ft, would achieve the desired local Mach number for the future inlet flight test. Interface plane distortion levels of 2 percent and a local angle of attack of -2 deg were observed at this condition. Alternative flight conditions for future testing and an exploration of certain anomalous data also are provided.

  3. Subscale Flight Testing for Aircraft Loss of Control: Accomplishments and Future Directions

    Science.gov (United States)

    Cox, David E.; Cunningham, Kevin; Jordan, Thomas L.

    2012-01-01

    Subscale flight-testing provides a means to validate both dynamic models and mitigation technologies in the high-risk flight conditions associated with aircraft loss of control. The Airborne Subscale Transport Aircraft Research (AirSTAR) facility was designed to be a flexible and efficient research facility to address this type of flight-testing. Over the last several years (2009-2011) it has been used to perform 58 research flights with an unmanned, remotely-piloted, dynamically-scaled airplane. This paper will present an overview of the facility and its architecture and summarize the experimental data collected. All flights to date have been conducted within visual range of a safety observer. Current plans for the facility include expanding the test volume to altitudes and distances well beyond visual range. The architecture and instrumentation changes associated with this upgrade will also be presented.

  4. An analysis of unit tests of a flight software product line

    NARCIS (Netherlands)

    Ganesan, D.; Lindvall, M.; McComas, D.; Bartholomew, M.; Slegel, S.; Medina, B.; Krikhaar, R.; Verhoef, C.; Dharmalingam, G.; Montgomery, L.P.

    2013-01-01

    This paper presents an analysis of the unit testing approach developed and used by the Core Flight Software System (CFS) product line team at the NASA Goddard Space Flight Center (GSFC). The goal of the analysis is to understand, review, and recommend strategies for improving the CFS' existing unit

  5. MSFC Doppler Lidar Science experiments and operations plans for 1981 airborne test flight

    Science.gov (United States)

    Fichtl, G. H.; Bilbro, J. W.; Kaufman, J. W.

    1981-01-01

    The flight experiment and operations plans for the Doppler Lidar System (DLS) are provided. Application of DLS to the study of severe storms and local weather penomena is addressed. Test plans involve 66 hours of flight time. Plans also include ground based severe storm and local weather data acquisition.

  6. A comparison of theory and flight test of the BO 105/BMR in hover and forward flight

    Science.gov (United States)

    Mirick, Paul H.

    1988-01-01

    Four cases were selected for comparison with theoretical predictions using stability data obtained during the flight test of the Bearingless Main Rotor (BMR) on a Messerschmidt-Boelkow-Blohm BO 105 helicopter. The four cases selected form the flight test included two ground resonance cases and two air resonance cases. The BMR used four modified BO 105 blades attached to a bearingless hub. The hub consisted of dual fiberglass C-channel beams attached to the hub center at 0.0238R and attached to the blade root at 0.25R with blade pitch control provided by a torque tube. Analyses from Bell Helicopter Textron, Boeing Vertol, and Sikorsky Aircraft were compared with the data and the correlation ranged from very poor-to-poor to poor-to-fair.

  7. Dive Angle Sensitivity Analysis for Flight Test Safety and Efficiency

    Science.gov (United States)

    2010-03-01

    22]. Raymer points out that most flutter modes are driven by improper balancing of control surfaces, but these flutter modes can be excited...description1.html [cited 2 Feb. 2010] [10] Nelson, Robert C., Flight Stability and Automatic Control, 2nd ed., McGraw-Hill Higher Education, Boston...Patuxent River Naval Air Station MD, May 1992, Chap. 10 [15] Raymer , Daniel, P., Aircraft Design: A Conceptual Approach, 4th ed., AIAA Education

  8. In-vitro tensile testing machine for vibration study of fresh rabbit Achilles tendon

    Science.gov (United States)

    Revel, Gian M.; Scalise, Alessandro; Scalise, Lorenzo; Pianosi, Antonella

    2001-10-01

    A lot of people, overall athletic one suffer from tendinitis or complete rupture of the Achilles tendon. This structure becomes inflamed and damaged mainly from a variety of mechanical forces and sometimes due to metabolic problems, such as diabetes or arthritis. Over the past three decades extensive studies have been performed on the structural and mechanical properties of Achilles tendon trying to explain the constitutive equations to describe and foresee tendon behavior. Among the various mechanical parameters, the vibrational behavior is also of interest. Several investigations are performed in order to study how the Achilles tendon vibrations influence the response of the muscle proprioception and human posture. The present article describes how in vitro tensile experiments can be performed, taking into account the need to simulate physiological condition of Achilles tendon and thus approaching some opened problems in the design of the experimental set-up. A new system for evaluating tendon vibrations by non contact techniques is proposed. Preliminary simple elongation tests are made extracting the main mechanical parameters: stress and strain at different fixed stretches, in order to characterize the tissue. Finally, a vibration study is made at each pretensioned tendon level evaluating the oscillating curves caused by a small hammer.

  9. Operational Overview for UAS Integration in the NAS Project Flight Test Series 3

    Science.gov (United States)

    Valkov, Steffi B.; Sternberg, Daniel; Marston, Michael

    2018-01-01

    The National Aeronautics and Space Administration Unmanned Aircraft Systems Integration in the National Airspace System Project has conducted a series of flight tests intended to support the reduction of barriers that prevent unmanned aircraft from flying without the required waivers from the Federal Aviation Administration. The 2015 Flight Test Series 3, supported two separate test configurations. The first configuration investigated the timing of Detect and Avoid alerting thresholds using a radar equipped unmanned vehicle and multiple live intruders flown at varying encounter geometries.

  10. Development of real-time on-line vibration testing system for seismic experiments

    International Nuclear Information System (INIS)

    Horiuchi, T.; Nakagawa, M.; Kametani, M.

    1993-01-01

    An on-line vibration testing method is being developed for seismic experiments. This method combines computer simulation and an actuator for vibration testing of structures. A real-time, on-line testing system was developed to improve the method. In the system, the timing of the vibration testing and the computer simulation are the same. This allows time-dependent reaction forces, such as damping force, to be immediately considered in the computer simulation. The real-time system has many requirements, such as complicated matrix calculations within a small time step, and communication with outer devices like sensors and actuators through A/D and D/A converters. These functions arc accomplished by using a newly-developed, real-time controller that employs a parallel processing technique. A small structural model is used to demonstrate the system. The reliability and applicability of the system for seismic experiments can be demonstrated by comparing the results of the system and a shaking table, which are in almost agreement. (author)

  11. Vibration test of 1/5 scale H-II launch vehicle

    Science.gov (United States)

    Morino, Yoshiki; Komatsu, Keiji; Sano, Masaaki; Minegishi, Masakatsu; Morita, Toshiyuki; Kohsetsu, Y.

    In order to predict dynamic loads on the newly designed Japanese H-II launch vehicle, the adequacy of prediction methods has been assessed by the dynamic scale model testing. The three-dimensional dynamic model was used in the analysis to express coupling effects among axial, lateral (pitch and yaw) and torsional vibrations. The liquid/tank interaction was considered by use of a boundary element method. The 1/5 scale model of the H-II launch vehicle was designed to simulate stiffness and mass properties of important structural parts, such as core/SRB junctions, first and second stage Lox tanks and engine mount structures. Modal excitation of the test vehicle was accomplished with 100-1000 N shakers which produced random or sinusoidal vibrational forces. The vibrational response of the test vehicle was measured at various locations with accelerometers and pressure sensor. In the lower frequency range, corresmpondence between analysis and experiment was generally good. The basic procedures in analysis seem to be adequate so far, but some improvements in mathematical modeling are suggested by comparison of test and analysis.

  12. Modelling of XCO2 Surfaces Based on Flight Tests of TanSat Instruments

    Directory of Open Access Journals (Sweden)

    Li Li Zhang

    2016-11-01

    Full Text Available The TanSat carbon satellite is to be launched at the end of 2016. In order to verify the performance of its instruments, a flight test of TanSat instruments was conducted in Jilin Province in September, 2015. The flight test area covered a total area of about 11,000 km2 and the underlying surface cover included several lakes, forest land, grassland, wetland, farmland, a thermal power plant and numerous cities and villages. We modeled the column-average dry-air mole fraction of atmospheric carbon dioxide (XCO2 surface based on flight test data which measured the near- and short-wave infrared (NIR reflected solar radiation in the absorption bands at around 760 and 1610 nm. However, it is difficult to directly analyze the spatial distribution of XCO2 in the flight area using the limited flight test data and the approximate surface of XCO2, which was obtained by regression modeling, which is not very accurate either. We therefore used the high accuracy surface modeling (HASM platform to fill the gaps where there is no information on XCO2 in the flight test area, which takes the approximate surface of XCO2 as its driving field and the XCO2 observations retrieved from the flight test as its optimum control constraints. High accuracy surfaces of XCO2 were constructed with HASM based on the flight’s observations. The results showed that the mean XCO2 in the flight test area is about 400 ppm and that XCO2 over urban areas is much higher than in other places. Compared with OCO-2’s XCO2, the mean difference is 0.7 ppm and the standard deviation is 0.95 ppm. Therefore, the modelling of the XCO2 surface based on the flight test of the TanSat instruments fell within an expected and acceptable range.

  13. Preliminary test results of a flight management algorithm for fuel conservative descents in a time based metered traffic environment. [flight tests of an algorithm to minimize fuel consumption of aircraft based on flight time

    Science.gov (United States)

    Knox, C. E.; Cannon, D. G.

    1979-01-01

    A flight management algorithm designed to improve the accuracy of delivering the airplane fuel efficiently to a metering fix at a time designated by air traffic control is discussed. The algorithm provides a 3-D path with time control (4-D) for a test B 737 airplane to make an idle thrust, clean configured descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path is calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithms and the results of the flight tests are discussed.

  14. Study on vibration alleviating properties of glass fiber reinforced polymer concrete through orthogonal tests

    International Nuclear Information System (INIS)

    Bai Wenfeng; Zhang Jianhua; Yan Peng; Wang Xinli

    2009-01-01

    Polymer concrete (PC), because of its good vibration alleviating properties, is a proper material for elementary machine parts in high-precision machine tools. Glass fiber was applied in PC to improve its mechanical properties, and the material obtained is called glass fiber reinforced polymer concrete (GFRPC). The best parameter to estimate the vibration alleviating property is damping ratio. Orthogonal tests were carried out to prepare GFRPC specimens with different component proportions. Damping ratio of the GFRPC specimens was measured. The effect of the factors considered in the experiments on damping ratio of GFRPC was studied. Results of the tests show that granite proportion plays the most important role in determining damping ratio of GFRPC, then flexibilizer dosage and glass fiber length, while epoxy resin dosage and glass fiber dosage play a comparatively less important part. Detailed descriptions were made about how the considered factors affect damping ratio of GFRPC in this paper

  15. Configuration management issues and objectives for a real-time research flight test support facility

    Science.gov (United States)

    Yergensen, Stephen; Rhea, Donald C.

    1988-01-01

    Presented are some of the critical issues and objectives pertaining to configuration management for the NASA Western Aeronautical Test Range (WATR) of Ames Research Center. The primary mission of the WATR is to provide a capability for the conduct of aeronautical research flight test through real-time processing and display, tracking, and communications systems. In providing this capability, the WATR must maintain and enforce a configuration management plan which is independent of, but complimentary to, various research flight test project configuration management systems. A primary WATR objective is the continued development of generic research flight test project support capability, wherein the reliability of WATR support provided to all project users is a constant priority. Therefore, the processing of configuration change requests for specific research flight test project requirements must be evaluated within a perspective that maintains this primary objective.

  16. Seismic evaluation of BWR spent fuel storage racks using actual damping by vibration test in water

    International Nuclear Information System (INIS)

    Yamasaki, Hiroto; Iwakura, Shigeyoshi; Imaoka, Tetsuo; Okumura, Kazue; Orita, Syuichi; Namita, Yoshio

    2010-01-01

    Damping value for BWR spent fuel storage racks has been used 1 percent damping, which is applied to welded steel structures in air as defined JEAG4601. However, it is considered that the actual damping is higher than that of the above mentioned, because of its underwater installation. This report shows the actual damping value of the Check Arrayed Rack by vibration test in water and Evaluation by the analysis of rack using actual damping. (author)

  17. Over-the-road shock and vibration testing of the radioisotope thermoelectric generator transportation system

    International Nuclear Information System (INIS)

    Becker, D.L.

    1997-01-01

    Radioisotope Thermoelectric Generators (RTG) convert heat generated by radioactive decay into electricity through the use of thermocouples. The RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance, which make them particularly attractive for use in spacecraft. However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title 10, Code of Federal Regulations, Part 71 (10 CFR 71). To meet these regulations, a RTG Transportation System (RTGTS) that fully complies with 10 CFR 71 has been developed, which protects RTGs from adverse environmental conditions during normal conditions of transport (e.g., shock, vibration, and heat). To ensure the protection of RTGs from shock and vibration loadings during transport, extensive over-the-road testing was conducted on the RTG'S to obtain real-time recordings of accelerations of the air-ride suspension system trailer floor, packaging, and support structure. This paper provides an overview of the RTG'S, a discussion of the shock and vibration testing, and a comparison of the test results to the specified shock response spectra and power spectral density acceleration criteria

  18. Vibration Durability Testing of Nickel Cobalt Aluminum Oxide (NCA Lithium-Ion 18650 Battery Cells

    Directory of Open Access Journals (Sweden)

    James Michael Hooper

    2016-04-01

    Full Text Available This paper outlines a study undertaken to determine if the electrical performance of Nickel Cobalt Aluminum Oxide (NCA 3.1 Ah 18650 battery cells can be degraded by road induced vibration typical of an electric vehicle (EV application. This study investigates if a particular cell orientation within the battery assembly can result in different levels of cell degradation. The 18650 cells were evaluated in accordance with Society of Automotive Engineers (SAE J2380 standard. This vibration test is synthesized to represent 100,000 miles of North American customer operation at the 90th percentile. This study identified that both the electrical performance and the mechanical properties of the NCA lithium-ion cells were relatively unaffected when exposed to vibration energy that is commensurate with a typical vehicle life. Minor changes observed in the cell’s electrical characteristics were deemed not to be statistically significant and more likely attributable to laboratory conditions during cell testing and storage. The same conclusion was found, irrespective of cell orientation during the test.

  19. NASA-FAA helicopter Microwave Landing System curved path flight test

    Science.gov (United States)

    Swenson, H. N.; Hamlin, J. R.; Wilson, G. W.

    1984-01-01

    An ongoing series of joint NASA/FAA helicopter Microwave Landing System (MLS) flight tests was conducted at Ames Research Center. This paper deals with tests done from the spring through the fall of 1983. This flight test investigated and developed solutions to the problem of manually flying curved-path and steep glide slope approaches into the terminal area using the MLS and flight director guidance. An MLS-equipped Bell UH-1H helicopter flown by NASA test pilots was used to develop approaches and procedures for flying these approaches. The approaches took the form of Straight-in, U-turn, and S-turn flightpaths with glide slopes of 6 deg, 9 deg, and 12 deg. These procedures were evaluated by 18 pilots from various elements of the helicopter community, flying a total of 221 hooded instrument approaches. Flying these curved path and steep glide slopes was found to be operationally acceptable with flight director guidance using the MLS.

  20. Preliminary studies of microchannel plate photomultiplier tube neutron detectors for flight test applications

    International Nuclear Information System (INIS)

    Dolan, K.W.

    1978-10-01

    Electrical, mechanical, thermal, and neutron response data indicate that microchannel plate photomultiplier tubes are viable candidates as miniature, ruggedized neutron detectors for flight test applications in future weapon systems

  1. Executive Summary of Propulsion on the Orion Abort Flight-Test Vehicles

    Science.gov (United States)

    Jones, Daniel S.; Brooks, Syri J.; Barnes, Marvin W.; McCauley, Rachel J.; Wall, Terry M.; Reed, Brian D.; Duncan, C. Miguel

    2012-01-01

    The National Aeronautics and Space Administration Orion Flight Test Office was tasked with conducting a series of flight tests in several launch abort scenarios to certify that the Orion Launch Abort System is capable of delivering astronauts aboard the Orion Crew Module to a safe environment, away from a failed booster. The first of this series was the Orion Pad Abort 1 Flight-Test Vehicle, which was successfully flown on May 6, 2010 at the White Sands Missile Range in New Mexico. This report provides a brief overview of the three propulsive subsystems used on the Pad Abort 1 Flight-Test Vehicle. An overview of the propulsive systems originally planned for future flight-test vehicles is also provided, which also includes the cold gas Reaction Control System within the Crew Module, and the Peacekeeper first stage rocket motor encased within the Abort Test Booster aeroshell. Although the Constellation program has been cancelled and the operational role of the Orion spacecraft has significantly evolved, lessons learned from Pad Abort 1 and the other flight-test vehicles could certainly contribute to the vehicle architecture of many future human-rated space launch vehicles

  2. Environmental control and life support testing at the Marshall Space Flight Center

    Science.gov (United States)

    Schunk, Richard G.; Humphries, William R.

    1987-01-01

    The Space Station Environmental Control and Life Support System (ECLSS) test program at the Marshall Space Flight Center (MSFC) is addressed. The immediate goals and current activities of the test program are discussed. Also described are the Core Module Integration Facility (CMIF) and the initial ECLSS test configuration. Future plans for the ECLSS test program and the CMIF are summarized.

  3. Qualification and Flight Test of Non-Chrome Primers for C-130 Aircraft

    Science.gov (United States)

    2011-08-17

    system  Significant hexavalent chrome reduction in finish system  Potential exposure level of spray applied chromated conversion coating not as...Lockheed Martin Aeronautics Company Qualification and Flight Test of Non- Chrome Primers for C-130 Aircraft Scott Jones Lockheed Martin...00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Qualification and Flight Test of Non- Chrome Primers for C-130 Aircraft 5a. CONTRACT NUMBER 5b. GRANT

  4. Finding of No Significant Impact and Environmental Assessment for Flight Test to the Edge of Space

    Science.gov (United States)

    2008-12-01

    Runway 22 or on Rogers Dry Lakebed at Edwards AFB. 17 On the basis of the findings of the Environmental Assessment, no significant impact to human...FLIGHT TEST CENTER Environmental Assessment for Flight Test to the Edge of Space Page 5-3 Bowles, A.E., S. Eckert, L . Starke, E. Berg, L . Wolski, and...Numbers. Anne Choate, Laura 20 Pederson , Jeremy Scharfenberg, Henry Farland. Washington, D.C. September. 21 Jeppesen Sanderson, Incorporated 22

  5. In-flight and ground testing of single event upset sensitivity in static RAMs

    International Nuclear Information System (INIS)

    Johansson, K.; Dyreklev, P.; Granbom, B.; Calvet, C.; Fourtine, S.; Feuillatre, O.

    1998-01-01

    This paper presents the results from in-flight measurements of single event upsets (SEU) in static random access memories (SRAM) caused by the atmospheric radiation environment at aircraft altitudes. The memory devices were carried on commercial airlines at high altitude and mainly high latitudes. The SEUs were monitored by a Component Upset Test Equipment (CUTE), designed for this experiment. The in flight results are compared to ground based testing with neutrons from three different sources

  6. Experimental testing on free vibration behaviour for silicone rubbers proposed within lumbar disc prosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Rotaru, Iuliana, E-mail: rotaruiuliana2000@gmail.com [“Gheorghe Asachi” Technical University of Iasi, Faculty of Mechanical Engineering, Department of Mechanical Engineering, Mechatronics and Robotics, 61-63 Bd. Dimitrie Mangeron, 700050 Iasi (Romania); “Gr. T. Popa” University of Medicine and Pharmacy of Iasi, Faculty of Medical Bioengineering, Department of Biomedical Sciences, 9-13 M. Kogalniceanu Street, 700454 Iasi (Romania); Bujoreanu, Carmen [“Gheorghe Asachi” Technical University of Iasi, Faculty of Mechanical Engineering, Department of Mechanical Engineering, Mechatronics and Robotics, 61-63 Bd. Dimitrie Mangeron, 700050 Iasi (Romania); Bele, Adrian; Cazacu, Maria [“Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41 A, 700487 Iasi (Romania); Olaru, Dumitru [“Gheorghe Asachi” Technical University of Iasi, Faculty of Mechanical Engineering, Department of Mechanical Engineering, Mechatronics and Robotics, 61-63 Bd. Dimitrie Mangeron, 700050 Iasi (Romania)

    2014-09-01

    This research was focused on the damping capacity study of two types of silicone rubbers proposed as layers within total lumbar disc prostheses of ball-and-socket model. In order to investigate the damping capacity, the two silicone rubber types mainly differing by the molecular mass of polymeric matrix and the filler content, as was emphasized by scanning electron microscopy and differential scanning calorimetry, were subjected to free vibration testing. Using an adapted experimental installation, three kinds of damping testing were realised: tests without samples and tests with three samples of each type of silicone rubber (69 ShA and 99 ShA). The free vibration tests were performed at a frequency of about 6 Hz using a weight of 11.8 kg. The relative damping coefficient was determined by measuring of two successive amplitudes on the vibrogram and calculating of the logarithmic decrement. The test results with silicone rubber samples showed a relative damping coefficient of 0.058 and respectively 0.077, whilst test results without samples showed a relative damping coefficient of 0.042. These silicone rubbers were found to have acceptable damping properties to be used as layers placed inside the prosthetic components. - Highlights: • Two types of silicone rubber were proposed within the total lumbar disc prostheses. • The filler content of elastomers was highlighted by microscopy investigation. • Damping capacity of the two elastomers was evaluated using free vibration analysis. • The logarithmic decrement and the relative damping coefficient were determined. • The silicone rubbers prepared in our work showed acceptable damping properties.

  7. Experimental testing on free vibration behaviour for silicone rubbers proposed within lumbar disc prosthesis

    International Nuclear Information System (INIS)

    Rotaru, Iuliana; Bujoreanu, Carmen; Bele, Adrian; Cazacu, Maria; Olaru, Dumitru

    2014-01-01

    This research was focused on the damping capacity study of two types of silicone rubbers proposed as layers within total lumbar disc prostheses of ball-and-socket model. In order to investigate the damping capacity, the two silicone rubber types mainly differing by the molecular mass of polymeric matrix and the filler content, as was emphasized by scanning electron microscopy and differential scanning calorimetry, were subjected to free vibration testing. Using an adapted experimental installation, three kinds of damping testing were realised: tests without samples and tests with three samples of each type of silicone rubber (69 ShA and 99 ShA). The free vibration tests were performed at a frequency of about 6 Hz using a weight of 11.8 kg. The relative damping coefficient was determined by measuring of two successive amplitudes on the vibrogram and calculating of the logarithmic decrement. The test results with silicone rubber samples showed a relative damping coefficient of 0.058 and respectively 0.077, whilst test results without samples showed a relative damping coefficient of 0.042. These silicone rubbers were found to have acceptable damping properties to be used as layers placed inside the prosthetic components. - Highlights: • Two types of silicone rubber were proposed within the total lumbar disc prostheses. • The filler content of elastomers was highlighted by microscopy investigation. • Damping capacity of the two elastomers was evaluated using free vibration analysis. • The logarithmic decrement and the relative damping coefficient were determined. • The silicone rubbers prepared in our work showed acceptable damping properties

  8. Experimental testing on free vibration behaviour for silicone rubbers proposed within lumbar disc prosthesis.

    Science.gov (United States)

    Rotaru, Iuliana; Bujoreanu, Carmen; Bele, Adrian; Cazacu, Maria; Olaru, Dumitru

    2014-09-01

    This research was focused on the damping capacity study of two types of silicone rubbers proposed as layers within total lumbar disc prostheses of ball-and-socket model. In order to investigate the damping capacity, the two silicone rubber types mainly differing by the molecular mass of polymeric matrix and the filler content, as was emphasized by scanning electron microscopy and differential scanning calorimetry, were subjected to free vibration testing. Using an adapted experimental installation, three kinds of damping testing were realised: tests without samples and tests with three samples of each type of silicone rubber (69 ShA and 99 ShA). The free vibration tests were performed at a frequency of about 6 Hz using a weight of 11.8 kg. The relative damping coefficient was determined by measuring of two successive amplitudes on the vibrogram and calculating of the logarithmic decrement. The test results with silicone rubber samples showed a relative damping coefficient of 0.058 and respectively 0.077, whilst test results without samples showed a relative damping coefficient of 0.042. These silicone rubbers were found to have acceptable damping properties to be used as layers placed inside the prosthetic components. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Design, analysis, and testing of a flexure-based vibration-assisted polishing device

    Science.gov (United States)

    Gu, Yan; Zhou, Yan; Lin, Jieqiong; Lu, Mingming; Zhang, Chenglong; Chen, Xiuyuan

    2018-05-01

    A vibration-assisted polishing device (VAPD) composed of leaf-spring and right-circular flexure hinges is proposed with the aim of realizing vibration-assisted machining along elliptical trajectories. To design the structure, energy methods and the finite-element method are used to calculate the performance of the proposed VAPD. An improved bacterial foraging optimization algorithm is used to optimize the structural parameters. In addition, the performance of the VAPD is tested experimentally. The experimental results indicate that the maximum strokes of the two directional mechanisms operating along the Z1 and Z2 directions are 29.5 μm and 29.3 μm, respectively, and the maximum motion resolutions are 10.05 nm and 10.01 nm, respectively. The maximum working bandwidth is 1,879 Hz, and the device has a good step response.

  10. Optimal deployment schedule of an active twist rotor for performance enhancement and vibration reduction in high-speed flights

    Directory of Open Access Journals (Sweden)

    Young H. YOU

    2017-08-01

    Full Text Available The best active twist schedules exploiting various waveform types are sought taking advantage of the global search algorithm for the reduction of hub vibration and/or power required of a rotor in high-speed conditions. The active twist schedules include two non-harmonic inputs formed based on segmented step functions as well as the simple harmonic waveform input. An advanced Particle Swarm assisted Genetic Algorithm (PSGA is employed for the optimizer. A rotorcraft Computational Structural Dynamics (CSD code CAMRAD II is used to perform the rotor aeromechanics analysis. A Computation Fluid Dynamics (CFD code is coupled with CSD for verification and some physical insights. The PSGA optimization results are verified against the parameter sweep study performed using the harmonic actuation. The optimum twist schedules according to the performance and/or vibration reduction strategy are obtained and their optimization gains are compared between the actuation cases. A two-phase non-harmonic actuation schedule demonstrates the best outcome in decreasing the power required while a four-phase non-harmonic schedule results in the best vibration reduction as well as the simultaneous reductions in the power required and vibration. The mechanism of reduction to the performance gains is identified illustrating the section airloads, angle-of-attack distribution, and elastic twist deformation predicted by the present approaches.

  11. Design Challenges Encountered in a Propulsion-Controlled Aircraft Flight Test Program

    Science.gov (United States)

    Maine, Trindel; Burken, John; Burcham, Frank; Schaefer, Peter

    1994-01-01

    The NASA Dryden Flight Research Center conducted flight tests of a propulsion-controlled aircraft system on an F-15 airplane. This system was designed to explore the feasibility of providing safe emergency landing capability using only the engines to provide flight control in the event of a catastrophic loss of conventional flight controls. Control laws were designed to control the flightpath and bank angle using only commands to the throttles. Although the program was highly successful, this paper highlights some of the challenges associated with using engine thrust as a control effector. These challenges include slow engine response time, poorly modeled nonlinear engine dynamics, unmodeled inlet-airframe interactions, and difficulties with ground effect and gust rejection. Flight and simulation data illustrate these difficulties.

  12. Torque Tension Testing of Fasteners used for NASA Flight Hardware Applications

    Science.gov (United States)

    Hemminger, Edgar G.; Posey, Alan J.; Dube, Michael J.

    2014-01-01

    The effect of various lubricants and other compounds on fastener torque-tension relationships is evaluated. Testing was performed using a unique test apparatus developed by Posey at the NASA Goddard Space Flight Center. A description of the test methodology, including associated data collection and analysis will be presented. Test results for 300 series CRES and A286 heat resistant fasteners, torqued into various types of inserts will be presented. The primary objective of this testing was to obtain torque-tension data for use on NASA flight projects.

  13. Development of a test and flight engineering oriented language, phase 3

    Science.gov (United States)

    Kamsler, W. F.; Case, C. W.; Kinney, E. L.; Gyure, J.

    1970-01-01

    Based on an analysis of previously developed test oriented languages and a study of test language requirements, a high order language was designed to enable test and flight engineers to checkout and operate the proposed space shuttle and other NASA vehicles and experiments. The language is called ALOFT (a language oriented to flight engineering and testing). The language is described, its terminology is compared to similar terms in other test languages, and its features and utilization are discussed. The appendix provides the specifications for ALOFT.

  14. Research on the Random Shock Vibration Test Based on the Filter-X LMS Adaptive Inverse Control Algorithm

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2016-01-01

    Full Text Available The related theory and algorithm of adaptive inverse control were presented through the research which pointed out the adaptive inverse control strategy could effectively eliminate the noise influence on the system control. Proposed using a frequency domain filter-X LMS adaptive inverse control algorithm, and the control algorithm was applied to the two-exciter hydraulic vibration test system of random shock vibration control process and summarized the process of the adaptive inverse control strategies in the realization of the random shock vibration test. The self-closed-loop and field test show that using the frequency-domain filter-X LMS adaptive inverse control algorithm can realize high precision control of random shock vibration test.

  15. Forced vibration tests and simulation analyses of a nuclear reactor building. Part 2: simulation analyses

    International Nuclear Information System (INIS)

    Kuno, M.; Nakagawa, S.; Momma, T.; Naito, Y.; Niwa, M.; Motohashi, S.

    1995-01-01

    Forced vibration tests of a BWR-type reactor building. Hamaoka Unit 4, were performed. Valuable data on the dynamic characteristics of the soil-structure interaction system were obtained through the tests. Simulation analyses of the fundamental dynamic characteristics of the soil-structure system were conducted, using a basic lumped mass soil-structure model (lattice model), and strong correlation with the measured data was obtained. Furthermore, detailed simulation models were employed to investigate the effects of simultaneously induced vertical response and response of the adjacent turbine building on the lateral response of the reactor building. (author). 4 refs., 11 figs

  16. A hydrostatic leak test for water pipeline by using distributed optical fiber vibration sensing system

    Science.gov (United States)

    Wu, Huijuan; Sun, Zhenshi; Qian, Ya; Zhang, Tao; Rao, Yunjiang

    2015-07-01

    A hydrostatic leak test for water pipeline with a distributed optical fiber vibration sensing (DOVS) system based on the phase-sensitive OTDR technology is studied in this paper. By monitoring one end of a common communication optical fiber cable, which is laid in the inner wall of the pipe, we can detect and locate the water leakages easily. Different apertures under different pressures are tested and it shows that the DOVS has good responses when the aperture is equal or larger than 4 mm and the inner pressure reaches 0.2 Mpa for a steel pipe with DN 91cm×EN 2cm.

  17. An evaluation of iced bridge hanger vibrations through wind tunnel testing and quasi-steady theory

    DEFF Research Database (Denmark)

    Gjelstrup, Henrik; Georgakis, Christos T.; Larsen, A.

    2012-01-01

    roughness is also examined. The static force coefficients are used to predict parameter regions where aerodynamic instability of the iced bridge hanger might be expected to occur, through use of an adapted theoretical 3- DOF quasi-steady galloping instability model, which accounts for sectional axial...... rotation. A comparison between the 3-DOF model and the instabilities found through two degree-of-freedom (2-DOF) dynamic tests is presented. It is shown that, although there is good agreement between the instabilities found through use of the quasi-steady theory and the dynamic tests, discrepancies exist......-indicating the possible inability of quasi-steady theory to fully predict these vibrational instabilities....

  18. Another Look at the Draft Mil-Std-1540E Unit Random Vibration Test Requirements

    Science.gov (United States)

    Perl, E.; Peterson, A. J..; Davis, D.

    2012-07-01

    The draft Mil-Std-1540E has been updated to reflect lessons learned since its publication as an SMC Standard in 2008, [1], and an earlier Aerospace Corporation Technical Report released in 2006, [2]. This paper discusses the technical rationale supporting some of the unit random vibration test requirements to provide better insight into their derivation and application to programs. It is intended that these requirements be tailored for each program to reflect the customer risk profile. Several tailoring options are provided and a two phase test strategy is discussed to highlight its applicability to utilizing heritage hardware in new applications.

  19. The Use of Dynamic Visual Acuity as a Functional Test of Gaze Stabilization Following Space Flight

    Science.gov (United States)

    Peters, B. T.; Mulavara, A. P.; Brady, R.; Miller, C. A.; Richards, J. T.; Warren, L. E.; Cohen, H. S.; Bloomberg, J. J.

    2006-01-01

    After prolonged exposure to a given gravitational environment the transition to another is accompanied by adaptations in the sensorimotor subsystems, including the vestibular system. Variation in the adaptation time course of these subsystems, and the functional redundancies that exist between them make it difficult to accurately assess the functional capacity and physical limitations of astro/cosmonauts using tests on individual subsystems. While isolated tests of subsystem performance may be the only means to address where interventions are required, direct measures of performance may be more suitable for assessing the operational consequences of incomplete adaptation to changes in the gravitational environment. A test of dynamic visual acuity (DVA) is currently being used in the JSC Neurosciences Laboratory as part of a series of measures to assess the efficacy of a countermeasure to mitigate postflight locomotor dysfunction. In the current protocol, subjects visual acuity is determined using Landolt ring optotypes presented sequentially on a computer display. Visual acuity assessments are made both while standing and while walking at 1.8 m/s on a motorized treadmill. The use of a psychophysical threshold detection algorithm reduces the required number of optotype presentations and the results can be presented immediately after the test. The difference between the walking and standing acuity measures provides a metric of the change in the subject s ability to maintain gaze fixation on the visual target while walking. This functional consequence is observable regardless of the underlying subsystem most responsible for the change. Data from 15 cosmo/astronauts have been collected following long-duration (approx. 6 months) stays in space using a visual target viewing distance of 4.0 meters. An investigation of the group mean shows a change in DVA soon after the flight that asymptotes back to baseline approximately one week following their return to earth. The

  20. Shuttle Rudder/Speed Brake Power Drive Unit (PDU) Gear Scuffing Tests With Flight Gears

    Science.gov (United States)

    Proctor, Margaret P.; Oswald, Fred B.; Krants, Timothy L.

    2005-01-01

    Scuffing-like damage has been found on the tooth surfaces of gears 5 and 6 of the NASA space shuttle rudder/speed brake power drive unit (PDU) number 2 after the occurrence of a transient back-driving event in flight. Tests were conducted using a pair of unused spare flight gears in a bench test at operating conditions up to 2866 rpm and 1144 in.-lb at the input ring gear and 14,000 rpm and 234 in.-lb at the output pinion gear, corresponding to a power level of 52 hp. This test condition exceeds the maximum estimated conditions expected in a backdriving event thought to produce the scuffing damage. Some wear marks were produced, but they were much less severe than the scuffing damaged produced during shuttle flight. Failure to produce scuff damage like that found on the shuttle may be due to geometrical variations between the scuffed gears and the gears tested herein, more severe operating conditions during the flight that produced the scuff than estimated, the order of the test procedures, the use of new hydraulic oil, differences between the dynamic response of the flight gearbox and the bench-test gearbox, or a combination of these. This report documents the test gears, apparatus, and procedures, summarizes the test results, and includes a discussion of the findings, conclusions, and recommendations.

  1. Vibration Diagnostics as an effective Tool for Testing Engines of Internal Combustion

    Directory of Open Access Journals (Sweden)

    Ferenc Dömötör

    2017-10-01

    Full Text Available There are several methods of automotive diagnostics used in services to detect a large variety of faults and damages of various parts of engines of internal combustion. Undoubtedly, they are effective, but they are simply unable to find all types of mechanical faults occurring during the operation. This is the reason why authors of this paper tried to use a special tool, which has been proven for years for detecting faults of rolling element bearing in rotating machinery. During their research, the authors tried to find valuable results by measuring vibration of various parts of engines. Three items were tested, a Diesel engine and two Otto motors. A large number of measurements have been taken at various speed, at different points, in different directions, with different parameter setup, etc. However, there was one setup which has been applied to all three engines. It is the measurement setup of vibration velocity, in the frequency range of 2 Hz-300 Hz. Valuable consequences have been found regarding the clogging of the air filters and the exhaust systems. As a conclusion the authors expressed their opinion, that, apart from the traditional diagnostic methods used in services, vibration measurements can also be useful, especially for detecting faults of rolling element bearings.

  2. Non Nuclear Testing of Reactor Systems In The Early Flight Fission Test Facilities (EFF-TF)

    International Nuclear Information System (INIS)

    Van Dyke, Melissa; Martin, James

    2004-01-01

    The Early Flight Fission-Test Facility (EFF-TF) can assist in the design and development of systems through highly effective non-nuclear testing of nuclear systems when technical issues associated with near-term space fission systems are 'non-nuclear' in nature (e.g. system's nuclear operations are understood). For many systems, thermal simulators can be used to closely mimic fission heat deposition. Axial power profile, radial power profile, and fuel pin thermal conductivity can be matched. In addition to component and subsystem testing, operational and lifetime issues associated with the steady state and transient performance of the integrated reactor module can be investigated. Instrumentation at the EFF-TF allows accurate measurement of temperature, pressure, strain, and bulk core deformation (useful for accurately simulating nuclear behavior). Ongoing research at the EFF-TF is geared towards facilitating research, development, system integration, and system utilization via cooperative efforts with DOE laboratories, industry, universities, and other Nasa centers. This paper describes the current efforts for the latter portion of 2003 and beginning of 2004. (authors)

  3. Test rig with active damping control for the simultaneous evaluation of vibration control and energy harvesting via piezoelectric transducers

    International Nuclear Information System (INIS)

    Perfetto, S; Rohlfing, J; Infante, F; Mayer, D; Herold, S

    2016-01-01

    Piezoelectric transducers can be used to harvest electrical energy from structural vibrations in order to power continuously operating condition monitoring systems local to where they operate. However, excessive vibrations can compromise the safe operation of mechanical systems. Therefore, absorbers are commonly used to control vibrations. With an integrated device, the mechanical energy that otherwise would be dissipated can be converted via piezoelectric transducers. Vibration absorbers are designed to have high damping factors. Hence, the integration of transducers would lead to a low energy conversion. Efficient energy harvesters usually have low damping capabilities; therefore, they are not effective for vibration suppression. Thus, the design of an integrated device needs to consider the two conflicting requirements on the damping. This study focuses on the development of a laboratory test rig with a host structure and a vibration absorber with tunable damping via an active relative velocity feedback. A voice coil actuator is used for this purpose. To overcome the passive damping effects of the back electromagnetic force a novel voltage feedback control is proposed, which has been validated both in simulation and experimentally. The aim of this study is to have a test rig ready for the introduction of piezo-transducers and available for future experimental evaluations of the damping effect on the effectiveness of vibration reduction and energy harvesting efficiency. (paper)

  4. Test rig with active damping control for the simultaneous evaluation of vibration control and energy harvesting via piezoelectric transducers

    Science.gov (United States)

    Perfetto, S.; Rohlfing, J.; Infante, F.; Mayer, D.; Herold, S.

    2016-09-01

    Piezoelectric transducers can be used to harvest electrical energy from structural vibrations in order to power continuously operating condition monitoring systems local to where they operate. However, excessive vibrations can compromise the safe operation of mechanical systems. Therefore, absorbers are commonly used to control vibrations. With an integrated device, the mechanical energy that otherwise would be dissipated can be converted via piezoelectric transducers. Vibration absorbers are designed to have high damping factors. Hence, the integration of transducers would lead to a low energy conversion. Efficient energy harvesters usually have low damping capabilities; therefore, they are not effective for vibration suppression. Thus, the design of an integrated device needs to consider the two conflicting requirements on the damping. This study focuses on the development of a laboratory test rig with a host structure and a vibration absorber with tunable damping via an active relative velocity feedback. A voice coil actuator is used for this purpose. To overcome the passive damping effects of the back electromagnetic force a novel voltage feedback control is proposed, which has been validated both in simulation and experimentally. The aim of this study is to have a test rig ready for the introduction of piezo-transducers and available for future experimental evaluations of the damping effect on the effectiveness of vibration reduction and energy harvesting efficiency.

  5. [Micron]ADS-B Detect and Avoid Flight Tests on Phantom 4 Unmanned Aircraft System

    Science.gov (United States)

    Arteaga, Ricardo; Dandachy, Mike; Truong, Hong; Aruljothi, Arun; Vedantam, Mihir; Epperson, Kraettli; McCartney, Reed

    2018-01-01

    Researchers at the National Aeronautics and Space Administration Armstrong Flight Research Center in Edwards, California and Vigilant Aerospace Systems collaborated for the flight-test demonstration of an Automatic Dependent Surveillance-Broadcast based collision avoidance technology on a small unmanned aircraft system equipped with the uAvionix Automatic Dependent Surveillance-Broadcast transponder. The purpose of the testing was to demonstrate that National Aeronautics and Space Administration / Vigilant software and algorithms, commercialized as the FlightHorizon UAS"TM", are compatible with uAvionix hardware systems and the DJI Phantom 4 small unmanned aircraft system. The testing and demonstrations were necessary for both parties to further develop and certify the technology in three key areas: flights beyond visual line of sight, collision avoidance, and autonomous operations. The National Aeronautics and Space Administration and Vigilant Aerospace Systems have developed and successfully flight-tested an Automatic Dependent Surveillance-Broadcast Detect and Avoid system on the Phantom 4 small unmanned aircraft system. The Automatic Dependent Surveillance-Broadcast Detect and Avoid system architecture is especially suited for small unmanned aircraft systems because it integrates: 1) miniaturized Automatic Dependent Surveillance-Broadcast hardware; 2) radio data-link communications; 3) software algorithms for real-time Automatic Dependent Surveillance-Broadcast data integration, conflict detection, and alerting; and 4) a synthetic vision display using a fully-integrated National Aeronautics and Space Administration geobrowser for three dimensional graphical representations for ownship and air traffic situational awareness. The flight-test objectives were to evaluate the performance of Automatic Dependent Surveillance-Broadcast Detect and Avoid collision avoidance technology as installed on two small unmanned aircraft systems. In December 2016, four flight tests

  6. Development of adaptive helicopter seat systems for aircrew vibration mitigation

    Science.gov (United States)

    Chen, Yong; Wickramasinghe, Viresh; Zimcik, David G.

    2008-03-01

    Helicopter aircrews are exposed to high levels of whole body vibration during flight. This paper presents the results of an investigation of adaptive seat mount approaches to reduce helicopter aircrew whole body vibration levels. A flight test was conducted on a four-blade helicopter and showed that the currently used passive seat systems were not able to provide satisfactory protection to the helicopter aircrew in both front-back and vertical directions. Long-term exposure to the measured whole body vibration environment may cause occupational health issues such as spine and neck strain injuries for aircrew. In order to address this issue, a novel adaptive seat mount concept was developed to mitigate the vibration levels transmitted to the aircrew body. For proof-of-concept demonstration, a miniature modal shaker was properly aligned between the cabin floor and the seat frame to provide adaptive actuation authority. Adaptive control laws were developed to reduce the vibration transmitted to the aircrew body, especially the helmet location in order to minimize neck and spine injuries. Closed-loop control test have been conducted on a full-scale helicopter seat with a mannequin configuration and a large mechanical shaker was used to provide representative helicopter vibration profiles to the seat frame. Significant vibration reductions to the vertical and front-back vibration modes have been achieved simultaneously, which verified the technical readiness of the adaptive mount approach for full-scale flight test on the vehicle.

  7. NASA Langley Distributed Propulsion VTOL Tilt-Wing Aircraft Testing, Modeling, Simulation, Control, and Flight Test Development

    Science.gov (United States)

    Rothhaar, Paul M.; Murphy, Patrick C.; Bacon, Barton J.; Gregory, Irene M.; Grauer, Jared A.; Busan, Ronald C.; Croom, Mark A.

    2014-01-01

    Control of complex Vertical Take-Off and Landing (VTOL) aircraft traversing from hovering to wing born flight mode and back poses notoriously difficult modeling, simulation, control, and flight-testing challenges. This paper provides an overview of the techniques and advances required to develop the GL-10 tilt-wing, tilt-tail, long endurance, VTOL aircraft control system. The GL-10 prototype's unusual and complex configuration requires application of state-of-the-art techniques and some significant advances in wind tunnel infrastructure automation, efficient Design Of Experiments (DOE) tunnel test techniques, modeling, multi-body equations of motion, multi-body actuator models, simulation, control algorithm design, and flight test avionics, testing, and analysis. The following compendium surveys key disciplines required to develop an effective control system for this challenging vehicle in this on-going effort.

  8. Heart Rate Measures of Flight Test and Evaluation

    National Research Council Canada - National Science Library

    Bonner, Malcolm A; Wilson, Glenn F

    2001-01-01

    .... Because flying is a complex task, several measures are required to derive the best evaluation. This article describes the use of heart rate to augment the typical performance and subjective measures used in test and evaluation...

  9. Mode S data link transponder flight test results

    Science.gov (United States)

    1997-02-01

    The Federal Aviation Administration (FAA) William J. Hughes Technical Center is : in the unique position of having the facilities designed to test Mode S radars : and transponders. A vendor supplied an early production model of a Mode S : transponder...

  10. Second Stage (S-II) Arrives at Marshall Space Flight Center For Testing

    Science.gov (United States)

    2004-01-01

    The business end of a Second Stage (S-II) slowly emerges from the shipping container as workers prepare to transport the Saturn V component to the testing facility at MSFC. The Second Stage (S-II) underwent vibration and engine firing tests. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

  11. Control and Non-Payload Communications (CNPC) Prototype Radio Validation Flight Test Report

    Science.gov (United States)

    Shalkhauser, Kurt A.; Ishac, Joseph A.; Iannicca, Dennis C.; Bretmersky, Steven C.; Smith, Albert E.

    2017-01-01

    This report provides an overview and results from the unmanned aircraft (UA) Control and Non-Payload Communications (CNPC) Generation 5 prototype radio validation flight test campaign. The radios used in the test campaign were developed under cooperative agreement NNC11AA01A between the NASA Glenn Research Center and Rockwell Collins, Inc., of Cedar Rapids, Iowa. Measurement results are presented for flight tests over hilly terrain, open water, and urban landscape, utilizing radio sets installed into a NASA aircraft and ground stations. Signal strength and frame loss measurement data are analyzed relative to time and aircraft position, specifically addressing the impact of line-of-sight terrain obstructions on CNPC data flow. Both the radio and flight test system are described.

  12. Wind-tunnel development of an SR-71 aerospike rocket flight test configuration

    Science.gov (United States)

    Smith, Stephen C.; Shirakata, Norm; Moes, Timothy R.; Cobleigh, Brent R.; Conners, Timothy H.

    1996-01-01

    A flight experiment has been proposed to investigate the performance of an aerospike rocket motor installed in a lifting body configuration. An SR-71 airplane would be used to carry the aerospike configuration to the desired flight test conditions. Wind-tunnel tests were completed on a 4-percent scale SR-71 airplane with the aerospike pod mounted in various locations on the upper fuselage. Testing was accomplished using sting and blade mounts from Mach 0.6 to Mach 3.2. Initial test objectives included assessing transonic drag and supersonic lateral-directional stability and control. During these tests, flight simulations were run with wind-tunnel data to assess the acceptability of the configurations. Early testing demonstrated that the initial configuration with the aerospike pod near the SR-71 center of gravity was unsuitable because of large nosedown pitching moments at transonic speeds. The excessive trim drag resulting from accommodating this pitching moment far exceeded the excess thrust capability of the airplane. Wind-tunnel testing continued in an attempt to find a configuration suitable for flight test. Multiple configurations were tested. Results indicate that an aft-mounted model configuration possessed acceptable performance, stability, and control characteristics.

  13. Development of a EUV Test Facility at the Marshall Space Flight Center

    Science.gov (United States)

    West, Edward; Pavelitz, Steve; Kobayashi, Ken; Robinson, Brian; Cirtain, Johnathan; Gaskin, Jessica; Winebarger, Amy

    2011-01-01

    This paper will describe a new EUV test facility that is being developed at the Marshall Space Flight Center (MSFC) to test EUV telescopes. Two flight programs, HiC - high resolution coronal imager (sounding rocket) and SUVI - Solar Ultraviolet Imager (GOES-R), set the requirements for this new facility. This paper will discuss those requirements, the EUV source characteristics, the wavelength resolution that is expected and the vacuum chambers (Stray Light Facility, Xray Calibration Facility and the EUV test chamber) where this facility will be used.

  14. Acquisition/expulsion system for earth orbital propulsion system study. Volume 4: Flight test article

    Science.gov (United States)

    1973-01-01

    Two orbital test plans were prepared to verify one of the passive cryogenic storage tank/feedline candidate designs. One plan considered the orbital test article to be launched as a dedicated payload using an Atlas F burner launching configuration. The second plan proposed to launch the orbital test article as a secondary payload on the Titan E/Centaur proof flight. The secondary payload concept was pursued until January 1973, when work to build the hardware for this phase of the contract was terminated for lack of a sponsor for the flight. The dedicated payload launched on an Atlas F is described.

  15. Management Process of a Frequency Response Flight Test for Rotorcraft Flying Qualities Evaluation

    Directory of Open Access Journals (Sweden)

    João Otávio Falcão Arantes Filho

    2016-07-01

    Full Text Available This paper applies the frequency response methodology to characterize and analyze the flying qualities of longitudinal and lateral axes of a rotary-wing aircraft, AS355-F2. Using the results, it is possible to check the suitability of the aircraft in accordance with ADS-33E-PRF standard, whose flying qualities specifications criteria are based on parameters in the frequency domain. The key steps addressed in the study involve getting, by means of flight test data, the closed-loop dynamic responses including the design of the instrumentation and specification of the sensors to be used in the flight test campaign, the definition of the appropriate maneuvers characteristics for excitation of the aircraft, the planning and execution of the flight test to collect the data, and the proper data treatment, processing and analysis after the flight. After treatment of the collected data, single input-single output spectral analysis is performed. The results permit the analysis of the flying qualities characteristics, anticipation of the demands to which the pilot will be subjected during closed-loop evaluations and check of compliance with the aforementioned standard, within the range of consistent excitation frequencies for flight tests, setting the agility level of the test aircraft.

  16. Initial virtual flight test for a dynamically similar aircraft model with control augmentation system

    Directory of Open Access Journals (Sweden)

    Linliang Guo

    2017-04-01

    Full Text Available To satisfy the validation requirements of flight control law for advanced aircraft, a wind tunnel based virtual flight testing has been implemented in a low speed wind tunnel. A 3-degree-of-freedom gimbal, ventrally installed in the model, was used in conjunction with an actively controlled dynamically similar model of aircraft, which was equipped with the inertial measurement unit, attitude and heading reference system, embedded computer and servo-actuators. The model, which could be rotated around its center of gravity freely by the aerodynamic moments, together with the flow field, operator and real time control system made up the closed-loop testing circuit. The model is statically unstable in longitudinal direction, and it can fly stably in wind tunnel with the function of control augmentation of the flight control laws. The experimental results indicate that the model responds well to the operator’s instructions. The response of the model in the tests shows reasonable agreement with the simulation results. The difference of response of angle of attack is less than 0.5°. The effect of stability augmentation and attitude control law was validated in the test, meanwhile the feasibility of virtual flight test technique treated as preliminary evaluation tool for advanced flight vehicle configuration research was also verified.

  17. Wavelet analysis to decompose a vibration simulation signal to improve pre-distribution testing of packaging

    Science.gov (United States)

    Griffiths, K. R.; Hicks, B. J.; Keogh, P. S.; Shires, D.

    2016-08-01

    In general, vehicle vibration is non-stationary and has a non-Gaussian probability distribution; yet existing testing methods for packaging design employ Gaussian distributions to represent vibration induced by road profiles. This frequently results in over-testing and/or over-design of the packaging to meet a specification and correspondingly leads to wasteful packaging and product waste, which represent 15bn per year in the USA and €3bn per year in the EU. The purpose of the paper is to enable a measured non-stationary acceleration signal to be replaced by a constructed signal that includes as far as possible any non-stationary characteristics from the original signal. The constructed signal consists of a concatenation of decomposed shorter duration signals, each having its own kurtosis level. Wavelet analysis is used for the decomposition process into inner and outlier signal components. The constructed signal has a similar PSD to the original signal, without incurring excessive acceleration levels. This allows an improved and more representative simulated input signal to be generated that can be used on the current generation of shaker tables. The wavelet decomposition method is also demonstrated experimentally through two correlation studies. It is shown that significant improvements over current international standards for packaging testing are achievable; hence the potential for more efficient packaging system design is possible.

  18. Minute Impurities Contribute Significantly to Olfactory Receptor Ligand Studies: Tales from Testing the Vibration Theory.

    Science.gov (United States)

    Paoli, M; Münch, D; Haase, A; Skoulakis, E; Turin, L; Galizia, C G

    2017-01-01

    Several studies have attempted to test the vibrational hypothesis of odorant receptor activation in behavioral and physiological studies using deuterated compounds as odorants. The results have been mixed. Here, we attempted to test how deuterated compounds activate odorant receptors using calcium imaging of the fruit fly antennal lobe. We found specific activation of one area of the antennal lobe corresponding to inputs from a specific receptor. However, upon more detailed analysis, we discovered that an impurity of 0.0006% ethyl acetate in a chemical sample of benzaldehyde-d 5 was entirely responsible for a sizable odorant-evoked response in Drosophila melanogaster olfactory receptor cells expressing dOr42b. Without gas chromatographic purification within the experimental setup, this impurity would have created a difference in the responses of deuterated and nondeuterated benzaldehyde, suggesting that dOr42b be a vibration sensitive receptor, which we show here not to be the case. Our results point to a broad problem in the literature on use of non-GC-pure compounds to test receptor selectivity, and we suggest how the limitations can be overcome in future studies.

  19. Analysis of crack initiation and growth in the high level vibration test at Tadotsu

    International Nuclear Information System (INIS)

    Kassir, M.K.; Park, Y.J.; Hofmayer, C.H.; Bandyopadhyay, K.K.; Shteyngart, S.

    1993-08-01

    The High Level Vibration Test data are used to assess the accuracy and usefulness of current engineering methodologies for predicting crack initiation and growth in a cast stainless steel pipe elbow under complex, large amplitude loading. The data were obtained by testing at room temperature a large scale modified model of one loop of a PWR primary coolant system at the Tadotsu Engineering Laboratory in Japan. Fatigue crack initiation time is reasonably predicted by applying a modified local strain approach (Coffin-Mason-Goodman equation) in conjunction with Miner's rule of cumulative damage. Three fracture mechanics methodologies are applied to investigate the crack growth behavior observed in the hot leg of the model. These are: the ΔK methodology (Paris law), ΔJ concepts and a recently developed limit load stress-range criterion. The report includes a discussion on the pros and cons of the analysis involved in each of the methods, the role played by the key parameters influencing the formulation and a comparison of the results with the actual crack growth behavior observed in the vibration test program. Some conclusions and recommendations for improvement of the methodologies are also provided

  20. Force Limited Vibration Testing: Computation C2 for Real Load and Probabilistic Source

    Science.gov (United States)

    Wijker, J. J.; de Boer, A.; Ellenbroek, M. H. M.

    2014-06-01

    To prevent over-testing of the test-item during random vibration testing Scharton proposed and discussed the force limited random vibration testing (FLVT) in a number of publications, in which the factor C2 is besides the random vibration specification, the total mass and the turnover frequency of the load(test item), a very important parameter. A number of computational methods to estimate C2 are described in the literature, i.e. the simple and the complex two degrees of freedom system, STDFS and CTDFS, respectively. Both the STDFS and the CTDFS describe in a very reduced (simplified) manner the load and the source (adjacent structure to test item transferring the excitation forces, i.e. spacecraft supporting an instrument).The motivation of this work is to establish a method for the computation of a realistic value of C2 to perform a representative random vibration test based on force limitation, when the adjacent structure (source) description is more or less unknown. Marchand formulated a conservative estimation of C2 based on maximum modal effective mass and damping of the test item (load) , when no description of the supporting structure (source) is available [13].Marchand discussed the formal description of getting C 2 , using the maximum PSD of the acceleration and maximum PSD of the force, both at the interface between load and source, in combination with the apparent mass and total mass of the the load. This method is very convenient to compute the factor C 2 . However, finite element models are needed to compute the spectra of the PSD of both the acceleration and force at the interface between load and source.Stevens presented the coupled systems modal approach (CSMA), where simplified asparagus patch models (parallel-oscillator representation) of load and source are connected, consisting of modal effective masses and the spring stiffnesses associated with the natural frequencies. When the random acceleration vibration specification is given the CMSA

  1. Preliminary study for the reliability Assurance on results and procedure of the out-pile mechanical characterization test for a fuel assembly; Lateral Vibration Test (I)

    International Nuclear Information System (INIS)

    Lee, Kang Hee; Yoon, Kyung Hee; Kim, Hyung Kyu

    2007-01-01

    The reliability assurance with respect to the test procedure and results of the out-pile mechanical performance test for the nuclear fuel assembly is an essential task to assure the test quality and to get a permission for fuel loading into the commercial reactor core. For the case of vibration test, proper management and appropriate calibration of instruments and devices used in the test, various efforts to minimize the possible error during the test and signal acquisition process are needed. Additionally, the deep understanding both of the theoretical assumption and simplification for the signal processing/modal analysis and of the functions of the devices used in the test were highly required. In this study, the overall procedure and result of lateral vibration test were assembly's mechanical characterization were briefly introduced. A series of measures to assure and improve the reliability of the vibration test were discussed

  2. Preliminary study for the reliability Assurance on results and procedure of the out-pile mechanical characterization test for a fuel assembly; Lateral Vibration Test (I)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Hee; Yoon, Kyung Hee; Kim, Hyung Kyu [KAERI, Daejeon (Korea, Republic of)

    2007-07-01

    The reliability assurance with respect to the test procedure and results of the out-pile mechanical performance test for the nuclear fuel assembly is an essential task to assure the test quality and to get a permission for fuel loading into the commercial reactor core. For the case of vibration test, proper management and appropriate calibration of instruments and devices used in the test, various efforts to minimize the possible error during the test and signal acquisition process are needed. Additionally, the deep understanding both of the theoretical assumption and simplification for the signal processing/modal analysis and of the functions of the devices used in the test were highly required. In this study, the overall procedure and result of lateral vibration test were assembly's mechanical characterization were briefly introduced. A series of measures to assure and improve the reliability of the vibration test were discussed.

  3. Evaluation of Fast-Time Wake Vortex Models using Wake Encounter Flight Test Data

    Science.gov (United States)

    Ahmad, Nashat N.; VanValkenburg, Randal L.; Bowles, Roland L.; Limon Duparcmeur, Fanny M.; Gloudesman, Thijs; van Lochem, Sander; Ras, Eelco

    2014-01-01

    This paper describes a methodology for the integration and evaluation of fast-time wake models with flight data. The National Aeronautics and Space Administration conducted detailed flight tests in 1995 and 1997 under the Aircraft Vortex Spacing System Program to characterize wake vortex decay and wake encounter dynamics. In this study, data collected during Flight 705 were used to evaluate NASA's fast-time wake transport and decay models. Deterministic and Monte-Carlo simulations were conducted to define wake hazard bounds behind the wake generator. The methodology described in this paper can be used for further validation of fast-time wake models using en-route flight data, and for determining wake turbulence constraints in the design of air traffic management concepts.

  4. Linear Aerospike SR-71 Experiment (LASRE) dumps water after first in-flight cold flow test

    Science.gov (United States)

    1998-01-01

    The NASA SR-71A successfully completed its first cold flow flight as part of the NASA/Rocketdyne/Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) at NASA's Dryden Flight Research Center, Edwards, California on March 4, 1998. During a cold flow flight, gaseous helium and liquid nitrogen are cycled through the linear aerospike engine to check the engine's plumbing system for leaks and to check the engine operating characterisitics. Cold-flow tests must be accomplished successfully before firing the rocket engine experiment in flight. The SR-71 took off at 10:16 a.m. PST. The aircraft flew for one hour and fifty-seven minutes, reaching a maximum speed of Mach 1.58 before landing at Edwards at 12:13 p.m. PST. 'I think all in all we had a good mission today,' Dryden LASRE Project Manager Dave Lux said. Flight crew member Bob Meyer agreed, saying the crew 'thought it was a really good flight.' Dryden Research Pilot Ed Schneider piloted the SR-71 during the mission. Lockheed Martin LASRE Project Manager Carl Meade added, 'We are extremely pleased with today's results. This will help pave the way for the first in-flight engine data-collection flight of the LASRE.' The LASRE experiment was designed to provide in-flight data to help Lockheed Martin evaluate the aerodynamic characteristics and the handling of the SR-71 linear aerospike experiment configuration. The goal of the project was to provide in-flight data to help Lockheed Martin validate the computational predictive tools it was using to determine the aerodynamic performance of a future reusable launch vehicle. The joint NASA, Rocketdyne (now part of Boeing), and Lockheed Martin Linear Aerospike SR-71 Experiment (LASRE) completed seven initial research flights at Dryden Flight Research Center. Two initial flights were used to determine the aerodynamic characteristics of the LASRE apparatus (pod) on the back of the SR-71. Five later flights focused on the experiment itself. Two were used to cycle gaseous

  5. Prediction of high level vibration test results by use of available inelastic analysis techniques

    International Nuclear Information System (INIS)

    Hofmayer, C.H.; Park, Y.J.; Costello, J.F.

    1991-01-01

    As part of a cooperative study between the United States and Japan, the US Nuclear Regulatory Commission and the Ministry of International Trade and Industry of Japan agreed to perform a test program that would subject a large scale piping model to significant plastic strains under excitation conditions much greater than the design condition for nuclear power plants. The objective was to compare the results of the tests with state-of-the-art analyses. Comparisons were done at different excitation levels from elastic to elastic-plastic to levels where cracking was induced in the test model. The program was called the high Level Vibration Test (HLVT). The HLVT was performed on the seismic table at the Tadotsu Engineering Laboratory of Nuclear Power Engineering Test Center in Japan. The test model was constructed by modifying the 1/2.5 scale model of one loop of a PWR primary coolant system which was previously tested by NUPEC as part of their seismic proving test program. A comparison of various analysis techniques with test results shows a higher prediction error in the detailed strain values than in the overall response values. This prediction error is magnified as the plasticity in the test model increases. There is no significant difference in the peak responses between the simplified and the detailed analyses. A comparison between various detailed finite element model runs indicates that the material properties and plasticity modeling have a significant impact on the plastic strain responses under dynamic loading reversals. 5 refs., 12 figs

  6. Rotary Balance Wind Tunnel Testing for the FASER Flight Research Aircraft

    Science.gov (United States)

    Denham, Casey; Owens, D. Bruce

    2016-01-01

    Flight dynamics research was conducted to collect and analyze rotary balance wind tunnel test data in order to improve the aerodynamic simulation and modeling of a low-cost small unmanned aircraft called FASER (Free-flying Aircraft for Sub-scale Experimental Research). The impetus for using FASER was to provide risk and cost reduction for flight testing of more expensive aircraft and assist in the improvement of wind tunnel and flight test techniques, and control laws. The FASER research aircraft has the benefit of allowing wind tunnel and flight tests to be conducted on the same model, improving correlation between wind tunnel, flight, and simulation data. Prior wind tunnel tests include a static force and moment test, including power effects, and a roll and yaw damping forced oscillation test. Rotary balance testing allows for the calculation of aircraft rotary derivatives and the prediction of steady-state spins. The rotary balance wind tunnel test was conducted in the NASA Langley Research Center (LaRC) 20-Foot Vertical Spin Tunnel (VST). Rotary balance testing includes runs for a set of given angular rotation rates at a range of angles of attack and sideslip angles in order to fully characterize the aircraft rotary dynamics. Tests were performed at angles of attack from 0 to 50 degrees, sideslip angles of -5 to 10 degrees, and non-dimensional spin rates from -0.5 to 0.5. The effects of pro-spin elevator and rudder deflection and pro- and anti-spin elevator, rudder, and aileron deflection were examined. The data are presented to illustrate the functional dependence of the forces and moments on angle of attack, sideslip angle, and angular rate for the rotary contributions to the forces and moments. Further investigation is necessary to fully characterize the control effectors. The data were also used with a steady state spin prediction tool that did not predict an equilibrium spin mode.

  7. Vibration technique for non-destructive testing of carbon fiber reinforced plastic structures

    International Nuclear Information System (INIS)

    Miller, W.G.

    1982-01-01

    For nondestructive testing of structures of KFK (carbon fiber reinforced plastics) Adams and a group at the English University of Bristol, Department of Mechanical Engineering have developed a vibrational testing method. It is based on the fact that the decreasing self-oscillations of a structure can be measured in connection with a dynamical analysis at only one particular location of that structure. This way a damage can be localized and be quantized rawly. The mathematical model is simple and for every tested structure only one analysis is needed. Many kinds of damages in structures can be determined and reproduced especially in structures that represent typical cases of application of KFK in air and aerospace industry. (orig.) [de

  8. Current Hypersonic and Space Vehicle Flight Test and Instrumentation

    Science.gov (United States)

    2015-06-22

    ground station hardware and software. B. Space- based Platforms There are already in place several satellite based options to collecting and... Transceive data over very long range at low to very high altitudes DARPA: XS-1 Ground Based Aircraft Based Space Based Future Data...412TW-PA-15264 AIR FORCE TEST CENTER EDWARDS AIR FORCE BASE , CALIFORNIA AIR FORCE MATERIEL COMMAND UNITED STATES AIR FORCE REPORT

  9. Fixed Wing Performance. Theory and Flight Test Techniques

    Science.gov (United States)

    1977-07-01

    descent data by digital computer routines is common practice at both military and contractor test facilities. The Wautomatic data reduction process...inability to reach ruider pedals or foot controls , inability to fit through emergency egrean openlngs, etc. CONTROl. DESIGN Contiols must meot various...most important controls should be the easiest to reach and manipulate. Controls should never be located such that the hand or arm manipulating the

  10. Real-time flight test data distribution and display

    Science.gov (United States)

    Nesel, Michael C.; Hammons, Kevin R.

    1988-01-01

    Enhancements to the real-time processing and display systems of the NASA Western Aeronautical Test Range are described. Display processing has been moved out of the telemetry and radar acquisition processing systems super-minicomputers into user/client interactive graphic workstations. Real-time data is provided to the workstations by way of Ethernet. Future enhancement plans include use of fiber optic cable to replace the Ethernet.

  11. Mechanical and Vibration Testing of Carbon Fiber Composite Material with Embedded Piezoelectric Sensors

    Science.gov (United States)

    Duffy, Kirsten P.; Lerch, Bradley A.; Wilmoth, Nathan G.; Kray, Nicholas; Gemeinhardt, Gregory

    2012-01-01

    Piezoelectric materials have been proposed as a means of decreasing turbomachinery blade vibration either through a passive damping scheme, or as part of an active vibration control system. For polymer matrix fiber composite (PMFC) blades, the piezoelectric elements could be embedded within the blade material, protecting the brittle piezoceramic material from the airflow and from debris. Before implementation of a piezoelectric element within a PMFC blade, the effect on PMFC mechanical properties needs to be understood. This study attempts to determine how the inclusion of a packaged piezoelectric patch affects the material properties of the PMFC. Composite specimens with embedded piezoelectric patches were tested in four-point bending, short beam shear, and flatwise tension configurations. Results show that the embedded piezoelectric material does decrease the strength of the composite material, especially in flatwise tension, attributable to failure at the interface or within the piezoelectric element itself. In addition, the sensing properties of the post-cured embedded piezoelectric materials were tested, and performed as expected. The piezoelectric materials include a non-flexible patch incorporating solid piezoceramic material, and two flexible patch types incorporating piezoelectric fibers. The piezoceramic material used in these patches was Navy Type-II PZT.

  12. About a sequential method for non destructive testing of structures by mechanical vibrations

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2001-01-01

    The presence and growth of cracks voids or fields of pores under applied forces or environmental actions can produce a meaningful lowering in the proper frequencies of normal modes of mechanical vibration in structures.A quite general expression for the square of modes proper frequency as a functional of displacement field,density field and elastic moduli fields is used as a starting point.The effect of defects on frequency are modeled as equivalent changes in density and elastic moduli fields,introducing the concept of region of influence of each defect.An approximate expression is obtained which relates the relative lowering in the square of modes proper frequency with position,size,shape and orientation of defects in mode displacement field.Some simple examples of structural elements with cracks or fields of pores are considered.the connection with linear elastic fracture mechanics is briefly exemplified.A sequential method is proposed for non-destructive testing of structures using mechanical vibrations combined with properly chosen local nondestructive testing methods

  13. Flight Test of the F/A-18 Active Aeroelastic Wing Airplane

    Science.gov (United States)

    Voracek, David

    2007-01-01

    A viewgraph presentation of flight tests performed on the F/A active aeroelastic wing airplane is shown. The topics include: 1) F/A-18 AAW Airplane; 2) F/A-18 AAW Control Surfaces; 3) Flight Test Background; 4) Roll Control Effectiveness Regions; 5) AAW Design Test Points; 6) AAW Phase I Test Maneuvers; 7) OBES Pitch Doublets; 8) OBES Roll Doublets; 9) AAW Aileron Flexibility; 10) Phase I - Lessons Learned; 11) Control Law Development and Verification & Validation Testing; 12) AAW Phase II RFCS Envelopes; 13) AAW 1-g Phase II Flight Test; 14) Region I - Subsonic 1-g Rolls; 15) Region I - Subsonic 1-g 360 Roll; 16) Region II - Supersonic 1-g Rolls; 17) Region II - Supersonic 1-g 360 Roll; 18) Region III - Subsonic 1-g Rolls; 19) Roll Axis HOS/LOS Comparison Region II - Supersonic (open-loop); 20) Roll Axis HOS/LOS Comparison Region II - Supersonic (closed-loop); 21) AAW Phase II Elevated-g Flight Test; 22) Region I - Subsonic 4-g RPO; and 23) Phase II - Lessons Learned

  14. Clinical studies of the vibration syndrome using a cold stress test measuring finger temperature.

    Science.gov (United States)

    Gautherie, M

    1995-01-01

    Since nine years multicentre, transversal and longitudinal clinical studies on hand-arm, vibration-exposed patients are being performed in cooperation with French occupational medicine centers and social security institutions. These studies are based upon current clinical assessment and standardized, temperature-measuring cooling tests. Data acquisition uses a portable, 10-channel, micro-processor-based temperature recorder and miniature thermal sensors. Temperature is monitored at the ten finger tips continuously, before, during and after a cold stress performed in strictly controlled conditions. Data from examinations performed at outlying sites are transferred through the telephonic network to a central processing unit. Data analysis uses a specific, expert-type software procedure based upon previous clinical studies on (i) 238 "normal" subjects, and (ii) 3,046 patients with vascular disturbances of the upper extremities of various etiologies. This procedure includes a staging process which assigns each finger a class representing the degree of severity of the abnormalities of response to cold ("dysthermia") related to vascular disorders. All data processing is fully automatic and results in a printed examination report. To date, over 1,623 vibration-exposed forestry, building and mechanical workers were examined. Sixty-three per cent of patients had received high dose of vibration (daily use of chain saws, air hammers, ballast tampers over many years). Typical white finger attacks or only neurological symptoms were found in 36% and 23% of patients respectively. The rate of sever dysthermia was much higher in patients with white finger attacks (83%) than in patients without (32%). In 90% of the vibration-exposed patients, the severity of dysthermia has differed greatly from one finger to another and between hands, while in non-exposed patients with primary Raynaud syndrome the dysthermia are generally similar for all fingers but the thumbs. Of 208 forestry

  15. Vibration analysis of 1 MW gearbox for the Avedoere wind turbine. Test bed measurements

    International Nuclear Information System (INIS)

    Crone, A.

    1995-03-01

    The investigations had several purposes: Firstly, to determine and evaluate the structure-borne noise source strength of the gearbox, which is relevant for the final gear noise emission from the wind turbine. Secondly, to select the potentially least noisy gear set out of two, which have been made for the output gear stage. And Thirdly, to obtain the natural vibration modes of the gearbox structure, in order to determine if the structure-borne noise, transmitted to the wind turbine structure, will be amplified due to resonance conditions. Additional vibration tests were carried out. Among these, trials of 'in situ' measurement of the Transmission Error of the output gear stage, and measurements of the torsional vibrations of the input and output shaft. The test of the two output gear sets (from Flender AG and ELKRAFT A.m.b.A.) had the aim to determine the least noisy one of two different tooth profiles. Both gear sets were intended for the Avedoere Wind Turbine when it, in its first period of operation, is going to operate as a stall regulated turbine. After the first mesurements and the exchange of the Flender-designed gear set with the ELKRAFT-designed gear set, troubles with the backmost bearing of the intermediate shaft arose. The evaluation of the structure-borne noise source strength (expressed as the vibration velocity level), has in general been made at load conditions which correspond to the conditions in the wind turibne at a wind speed of 8 m/s, 10 m above terrain (v 10 ). This condition, is the one normally used when the noise emission from wind turbines is evaluated. At the comparison of the two gear sets against each other, the influence of the torque load on the source strength has also been considered. This comparison may indicate the load at which the profile correction is most effective, and may determine the noise potential of the gearbox at wind speeds lower than 8 m/s, which could also be of interest

  16. Testing command and control of the satellites in formation flight

    Science.gov (United States)

    Gheorghe, Popan; Gheorghe, Gh. Ion; Gabriel, Todoran

    2013-10-01

    The topics covered in the paper are mechatronic systems for determining the distance between the satellites and the design of the displacement system on air cushion table for satellites testing. INCDMTM has the capability to approach the collaboration within European Programms (ESA) of human exploration of outer space through mechatronic systems and accessories for telescopes, mechatronics systems used by the launchers, sensors and mechatronic systems for the robotic exploration programs of atmosphere and Mars. This research has a strong development component of industrial competitiveness many of the results of space research have direct applicability in industrial fabrication.

  17. The Skull Vibration-Induced Nystagmus Test of Vestibular Function—A Review

    Science.gov (United States)

    Dumas, Georges; Curthoys, Ian S.; Lion, Alexis; Perrin, Philippe; Schmerber, Sébastien

    2017-01-01

    A 100-Hz bone-conducted vibration applied to either mastoid induces instantaneously a predominantly horizontal nystagmus, with quick phases beating away from the affected side in patients with a unilateral vestibular loss (UVL). The same stimulus in healthy asymptomatic subjects has little or no effect. This is skull vibration-induced nystagmus (SVIN), and it is a useful, simple, non-invasive, robust indicator of asymmetry of vestibular function and the side of the vestibular loss. The nystagmus is precisely stimulus-locked: it starts with stimulation onset and stops at stimulation offset, with no post-stimulation reversal. It is sustained during long stimulus durations; it is reproducible; it beats in the same direction irrespective of which mastoid is stimulated; it shows little or no habituation; and it is permanent—even well-compensated UVL patients show SVIN. A SVIN is observed under Frenzel goggles or videonystagmoscopy and recorded under videonystagmography in absence of visual-fixation and strong sedative drugs. Stimulus frequency, location, and intensity modify the results, and a large variability in skull morphology between people can modify the stimulus. SVIN to 100 Hz mastoid stimulation is a robust response. We describe the optimum method of stimulation on the basis of the literature data and testing more than 18,500 patients. Recent neural evidence clarifies which vestibular receptors are stimulated, how they cause the nystagmus, and why the same vibration in patients with semicircular canal dehiscence (SCD) causes a nystagmus beating toward the affected ear. This review focuses not only on the optimal parameters of the stimulus and response of UVL and SCD patients but also shows how other vestibular dysfunctions affect SVIN. We conclude that the presence of SVIN is a useful indicator of the asymmetry of vestibular function between the two ears, but in order to identify which is the affected ear, other information and careful clinical judgment are

  18. Preliminary analysis of accelerated space flight ionizing radiation testing

    Science.gov (United States)

    Wilson, J. W.; Stock, L. V.; Carter, D. J.; Chang, C. K.

    1982-01-01

    A preliminary analysis shows that radiation dose equivalent to 30 years in the geosynchronous environment can be accumulated in a typical composite material exposed to space for 2 years or less onboard a spacecraft orbiting from perigee of 300 km out to the peak of the inner electron belt (approximately 2750 km). Future work to determine spacecraft orbits better tailored to materials accelerated testing is indicated. It is predicted that a range of 10 to the 9th power to 10 to the 10th power rads would be accumulated in 3-6 mil thick epoxy/graphite exposed by a test spacecraft orbiting in the inner electron belt. This dose is equivalent to the accumulated dose that this material would be expected to have after 30 years in a geosynchronous orbit. It is anticipated that material specimens would be brought back to Earth after 2 years in the radiation environment so that space radiation effects on materials could be analyzed by laboratory methods.

  19. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Flight Test Report

    Science.gov (United States)

    Iannicca, Dennis C.; Ishac, Joseph A.; Shalkhauser, Kurt A.

    2015-01-01

    NASA Glenn Research Center (GRC), in cooperation with Rockwell Collins, is working to develop a prototype Control and Non-Payload Communications (CNPC) radio platform as part of NASA Integrated Systems Research Program's (ISRP) Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. A primary focus of the project is to work with the Federal Aviation Administration (FAA) and industry standards bodies to build and demonstrate a safe, secure, and efficient CNPC architecture that can be used by industry to evaluate the feasibility of deploying a system using these technologies in an operational capacity. GRC has been working in conjunction with these groups to assess threats, identify security requirements, and to develop a system of standards-based security controls that can be applied to the GRC prototype CNPC architecture as a demonstration platform. The proposed security controls were integrated into the GRC flight test system aboard our S-3B Viking surrogate aircraft and several network tests were conducted during a flight on November 15th, 2014 to determine whether the controls were working properly within the flight environment. The flight test was also the first to integrate Robust Header Compression (ROHC) as a means of reducing the additional overhead introduced by the security controls and Mobile IPv6. The effort demonstrated the complete end-to-end secure CNPC link in a relevant flight environment.

  20. Test Hardware Design for Flight-Like Operation of Advanced Stirling Convertors

    Science.gov (United States)

    Oriti, Salvatore M.

    2012-01-01

    NASA Glenn Research Center (GRC) has been supporting development of the Advanced Stirling Radioisotope Generator (ASRG) since 2006. A key element of the ASRG project is providing life, reliability, and performance testing of the Advanced Stirling Convertor (ASC). For this purpose, the Thermal Energy Conversion branch at GRC has been conducting extended operation of a multitude of free-piston Stirling convertors. The goal of this effort is to generate long-term performance data (tens of thousands of hours) simultaneously on multiple units to build a life and reliability database. The test hardware for operation of these convertors was designed to permit in-air investigative testing, such as performance mapping over a range of environmental conditions. With this, there was no requirement to accurately emulate the flight hardware. For the upcoming ASC-E3 units, the decision has been made to assemble the convertors into a flight-like configuration. This means the convertors will be arranged in the dual-opposed configuration in a housing that represents the fit, form, and thermal function of the ASRG. The goal of this effort is to enable system level tests that could not be performed with the traditional test hardware at GRC. This offers the opportunity to perform these system-level tests much earlier in the ASRG flight development, as they would normally not be performed until fabrication of the qualification unit. This paper discusses the requirements, process, and results of this flight-like hardware design activity.

  1. Correlation of analysis with high level vibration test results for primary coolant piping

    International Nuclear Information System (INIS)

    Park, Y.J.; Hofmayer, C.H.; Costello, J.F.

    1992-01-01

    Dynamic tests on a modified 1/2.5-scale model of pressurized water reactor (PWR) primary coolant piping were performed using a large shaking table at Tadotsu, Japan. The High Level Vibration Test (HLVT) program was part of a cooperative study between the United States (Nuclear Regulatory Commission/Brookhaven National Laboratory, NRC/BNL) and Japan (Ministry of International Trade and Industry/Nuclear Power Engineering Center). During the test program, the excitation level of each test run was gradually increased up to the limit of the shaking table and significant plastic strains, as well as cracking, were induced in the piping. To fully utilize the test results, NRC/BNL sponsored a project to develop corresponding analytical predictions for the nonlinear dynamic response of the piping for selected test runs. The analyses were performed using both simplified and detailed approaches. The simplified approaches utilize a linear solution and an approximate formulation for nonlinear dynamic effects such as the use of a deamplification factor. The detailed analyses were performed using available nonlinear finite element computer codes, including the MARC, ABAQUS, ADINA and WECAN codes. A comparison of various analysis techniques with the test results shows a higher prediction error in the detailed strain values in the overall response values. A summary of the correlation analyses was presented before the BNL. This paper presents a detailed description of the various analysis results and additional comparisons with test results

  2. Results from the First Two Flights of the Static Computer Memory Integrity Testing Experiment

    Science.gov (United States)

    Hancock, Thomas M., III

    1999-01-01

    This paper details the scientific objectives, experiment design, data collection method, and post flight analysis following the first two flights of the Static Computer Memory Integrity Testing (SCMIT) experiment. SCMIT is designed to detect soft-event upsets in passive magnetic memory. A soft-event upset is a change in the logic state of active or passive forms of magnetic memory, commonly referred to as a "Bitflip". In its mildest form a soft-event upset can cause software exceptions, unexpected events, start spacecraft safeing (ending data collection) or corrupted fault protection and error recovery capabilities. In it's most severe form loss of mission or spacecraft can occur. Analysis after the first flight (in 1991 during STS-40) identified possible soft-event upsets to 25% of the experiment detectors. Post flight analysis after the second flight (in 1997 on STS-87) failed to find any evidence of soft-event upsets. The SCMIT experiment is currently scheduled for a third flight in December 1999 on STS-101.

  3. An evaluation of damping ratios for HVAC duct systems using vibration test data

    International Nuclear Information System (INIS)

    Gunyasu, K.; Horimizu, Y.; Kawakami, A.; Iokibe, H.; Yamazaki, T.

    1988-01-01

    The function of Heating Ventilating Air Conditioning (HVAC) systems must be maintained including HVAC duct systems to keep the operation of safety-related equipment in nuclear power plants during earthquake excitations. Therefore, it is important to carry out seismic design for HVAC duct systems. In the previous aseismic design for HVAC duct systems, the 0.5% damping ratio has been used in Japan. In recent years, vibration tests, held on actual duct systems in nuclear power plants and mockup duct systems were performed in order to investigate damping ratios for HVAC duct systems. Based on the results, it was confirmed that the damping ratio for HVAC duct systems, evaluated from these tests, were much greater than the 0.5% damping ratio used in the previous aseismic design of Japan. The new damping ratio in aseismic design was proposed to be 2.5%. The present paper describes the results of the above mentioned investigation

  4. Design, analysis and testing of a new piezoelectric tool actuator for elliptical vibration turning

    Science.gov (United States)

    Lin, Jieqiong; Han, Jinguo; Lu, Mingming; Yu, Baojun; Gu, Yan

    2017-08-01

    A new piezoelectric tool actuator (PETA) for elliptical vibration turning has been developed based on a hybrid flexure hinge connection. Two double parallel four-bar linkage mechanisms and two right circular flexure hinges were chosen to guide the motion. The two input displacement directional stiffness were modeled according to the principle of virtual work modeling method and the kinematic analysis was conducted theoretically. Finite element analysis was used to carry out static and dynamic analyses. To evaluate the performance of the developed PETA, off-line experimental tests were carried out to investigate the step responses, motion strokes, resolutions, parasitic motions, and natural frequencies of the PETA along the two input directions. The relationship between input displacement and output displacement, as well as the tool tip’s elliptical trajectory in different phase shifts was analyzed. By using the developed PETA mechanism, micro-dimple patterns were generated as the preliminary application to demonstrate the feasibility and efficiency of PETA for elliptical vibration turning.

  5. Malfunction tests and vibration analysis of P.W.R. internal structures

    International Nuclear Information System (INIS)

    Puyal, C.; Carre, J.C.; Epstein, A.

    1987-01-01

    To diagnose changes liable to occur in the vibration behavior of internals, it is important to understand the influence of changes in the mechanical properties of elements on the output signals obtained from neutron chambers placed out of core and accelerometers fixed to the reactor vessel. To do this, the effects of changes liable to occur in the hold-down springs and the flexures were simulated on the SAFRAN loop, using a representative hydroelastic mock-up. The results obtained experimentally on SAFRAN for different characteristics of the hold-down spring, which lies between the upper part of the core barrel and the vessel head, have been published. In this paper, we propose to present the results of the investigation of the fracture of one or more flexures which connect the cylindrical thermal shield to the core barrel. This work is in two parts: a) Computation based on a hydroelastic model using the substructuration computer program TRISTANA of the CASTEM system. b) Tests simulating flexure fracture: 1 - in air, for an understanding of the mechanisms involved; 2 - on the SAFRAN loop with a representative flow in order to estimate the strains liable to exist on the vibration signatures recorded on displacement transducers and accelerometers. Good agreement was observed between the computation results with the theoretical model employed and those obtained experimentally [fr

  6. Recent results of seismic isolation study in CRIEPI: Tests on seismic isolation elements, vibration tests and observations

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Katsuhiko; Shiojiri, Hiroo; Mazda, Taiji; Ohtori, Yasuki [Abiko Research Laboratory, Central Research Institute of Electric Power Industry (Japan); Aoyagi, Sakae [Central Research Institute of Electric Power Industry (Japan)

    1992-07-01

    Seismic isolation is expected to be effective in raising reliability during earthquake, reducing cost, enlarging and promoting the design standardization of electric power facilities. In Japan, it has been applied to several buildings. However it is considered that more research is needed to verify the reliability and effectiveness of seismic isolation for fast breeder reactors. In the preliminary study of isolation concepts for FBRs the horizontal base isolation of buildings was investigated in detail. The laminated rubber bearings were considered to be most suitable isolation system. Tests on large scale models of rubber bearing and vibration test of base isolation system have been conducted as well as the earthquake response observation of isolated buildings were conducted.

  7. Recent results of seismic isolation study in CRIEPI: Tests on seismic isolation elements, vibration tests and observations

    International Nuclear Information System (INIS)

    Ishida, Katsuhiko; Shiojiri, Hiroo; Mazda, Taiji; Ohtori, Yasuki; Aoyagi, Sakae

    1992-01-01

    Seismic isolation is expected to be effective in raising reliability during earthquake, reducing cost, enlarging and promoting the design standardization of electric power facilities. In Japan, it has been applied to several buildings. However it is considered that more research is needed to verify the reliability and effectiveness of seismic isolation for fast breeder reactors. In the preliminary study of isolation concepts for FBRs the horizontal base isolation of buildings was investigated in detail. The laminated rubber bearings were considered to be most suitable isolation system. Tests on large scale models of rubber bearing and vibration test of base isolation system have been conducted as well as the earthquake response observation of isolated buildings were conducted

  8. Effects of a whole body vibration training program on strength, power, and functional tests in the physically active elderly

    Directory of Open Access Journals (Sweden)

    Renata Gonçalves da Silva

    2009-04-01

    Full Text Available The aim of this study was to investigate the effect of a whole body vibration training program on knee extensor isokinetic peak torque, average power, and functional tests in the physically active elderly. Forty-seven subjects, who participated in a training program for the elderly, were recruited. The subjects were divided into two groups: whole body vibration group (WBV (n=24, 70.7±5.8 years, 62.7±12.3 kg and 155.9±8.0 cm and control group (n=23. 70.0±5.7 years, 65.3±10.7 kg and 157.9±6.6 cm. The WBS group underwent whole body vibration exercise and their regular training program for 13 weeks, 2 times per week, whereas the control group performed the regular training program only. Whole body vibration training was not effective in increasing isokinetic peak torque, average power, or performance in the functional tests. On the other hand, the regular training program was effective in increasing elbow flexor strength endurance, distance covered in the 6-min walk test, and speed in the timed up and go test. The results suggest that vibration training is not effective in modifying functionality or muscle strength and power in the physically active elderly.

  9. Implementation and Test of the Automatic Flight Dynamics Operations for Geostationary Satellite Mission

    Directory of Open Access Journals (Sweden)

    Sangwook Park

    2009-12-01

    Full Text Available This paper describes the Flight Dynamics Automation (FDA system for COMS Flight Dynamics System (FDS and its test result in terms of the performance of the automation jobs. FDA controls the flight dynamics functions such as orbit determination, orbit prediction, event prediction, and fuel accounting. The designed FDA is independent from the specific characteristics which are defined by spacecraft manufacturer or specific satellite missions. Therefore, FDA could easily links its autonomous job control functions to any satellite mission control system with some interface modification. By adding autonomous system along with flight dynamics system, it decreases the operator’s tedious and repeated jobs but increase the usability and reliability of the system. Therefore, FDA is used to improve the completeness of whole mission control system’s quality. The FDA is applied to the real flight dynamics system of a geostationary satellite, COMS and the experimental test is performed. The experimental result shows the stability and reliability of the mission control operations through the automatic job control.

  10. EUCLID/NISP GRISM qualification model AIT/AIV campaign: optical, mechanical, thermal and vibration tests

    Science.gov (United States)

    Caillat, A.; Costille, A.; Pascal, S.; Rossin, C.; Vives, S.; Foulon, B.; Sanchez, P.

    2017-09-01

    Dark matter and dark energy mysteries will be explored by the Euclid ESA M-class space mission which will be launched in 2020. Millions of galaxies will be surveyed through visible imagery and NIR imagery and spectroscopy in order to map in three dimensions the Universe at different evolution stages over the past 10 billion years. The massive NIR spectroscopic survey will be done efficiently by the NISP instrument thanks to the use of grisms (for "Grating pRISMs") developed under the responsibility of the LAM. In this paper, we present the verification philosophy applied to test and validate each grism before the delivery to the project. The test sequence covers a large set of verifications: optical tests to validate efficiency and WFE of the component, mechanical tests to validate the robustness to vibration, thermal tests to validate its behavior in cryogenic environment and a complete metrology of the assembled component. We show the test results obtained on the first grism Engineering and Qualification Model (EQM) which will be delivered to the NISP project in fall 2016.

  11. Simulation analyses of vibration tests on pile-group effects using blast-induced ground motions

    International Nuclear Information System (INIS)

    Takayuki Hashimoto; Kazushige Fujiwara; Katsuichirou Hijikata; Hideo Tanaka; Kohji Koyamada; Atsushi Suzuki; Osamu Kontani

    2005-01-01

    Extensive vibration tests have been performed on pile-supported structures at a large-scale mining site to promote better understanding of the dynamic behavior of pile-supported structures, especially pile-group effects. Two test structures were constructed in an excavated pit. One structure was supported on 25 tubular steel piles and the other on 4. The test pit was backfilled with sand of an appropriate grain size distribution to ensure good compaction. Ground motions induced by large-scale blasting operations were used as excitation forces for the tests. The 3D Finite Element Method (3D FEM)and a Genetic Algorithm (GA) were employed to identify the shear wave velocities and damping factors of the compacted sand, especially of the surface layer. A beam-interaction spring model was employed to simulate the test results of the piles and the pile-supported structures. The superstructure and pile foundation were modeled by a one-stick model comprising lumped masses and beam elements. The pile foundations were modeled just as they were, with lumped masses and beam elements to simulate the test results showing that, for the 25-pile structure, piles at different locations showed different responses. It was confirmed that the analysis methods employed were very useful for evaluating the nonlinear behavior of the soil-pile-structure system, even under severe ground motions. (authors)

  12. Distribution of base rock depth estimated from Rayleigh wave measurement by forced vibration tests

    International Nuclear Information System (INIS)

    Hiroshi Hibino; Toshiro Maeda; Chiaki Yoshimura; Yasuo Uchiyama

    2005-01-01

    This paper shows an application of Rayleigh wave methods to a real site, which was performed to determine spatial distribution of base rock depth from the ground surface. At a certain site in Sagami Plain in Japan, the base rock depth from surface is assumed to be distributed up to 10 m according to boring investigation. Possible accuracy of the base rock depth distribution has been needed for the pile design and construction. In order to measure Rayleigh wave phase velocity, forced vibration tests were conducted with a 500 N vertical shaker and linear arrays of three vertical sensors situated at several points in two zones around the edges of the site. Then, inversion analysis was carried out for soil profile by genetic algorithm, simulating measured Rayleigh wave phase velocity with the computed counterpart. Distribution of the base rock depth inverted from the analysis was consistent with the roughly estimated inclination of the base rock obtained from the boring tests, that is, the base rock is shallow around edge of the site and gradually inclines towards the center of the site. By the inversion analysis, the depth of base rock was determined as from 5 m to 6 m in the edge of the site, 10 m in the center of the site. The determined distribution of the base rock depth by this method showed good agreement on most of the points where boring investigation were performed. As a result, it was confirmed that the forced vibration tests on the ground by Rayleigh wave methods can be useful as the practical technique for estimating surface soil profiles to a depth of up to 10 m. (authors)

  13. Lessons learned from full-scale vibration tests on nuclear power plant auxiliary structure in Switzerland

    International Nuclear Information System (INIS)

    Berger, E.; Tinic, S.

    1988-01-01

    The Beznau Nuclear Power Plant is located in northern Switzerland. The plant is owned and operated by the Nordostschweizerische Kraftwerke AG (NOK) in Baden, Switzerland. It is a twin unit plant (2 x 350 MWe) which was designed in the early 1960's and placed into commercial operation between 1969 and 1971. In connection with a major backfit project, which will improve the safety of the plant against external events, the free-standing boric water tanks had to be relocated and were replaced by two boric water tanks in a new building (the so called BOTA-building). It enabled to plan and perform full scale vibration tests.The scope of experimental investigation was to determine the eigenfrequencies and damping values for fundamental soil-structure interaction. The vibration tests allowed identification of the important modes of the soil-structure system in the range 3 to 15 Hz. The excitation was strung enough to generate accelerations in the structure comparable to those of a small earthquake. From the comparisons of computed and measured results it is concluded that the rocking frequency can be reasonably well predicted by either Finite Element or Lumped Parameter models with springs simulating the soil-foundation stiffness, provided in the case of the latter the embedment is taken into account. The prediction of the amplitude of structural response appears to be more difficult, as shown by the differences in the mode shapes. In the frequency range 8 to 10 Hz the agreement between computed and test results was less satisfactory. The actual structural behaviour turned out to be more complex than expected and needs further investigation with the aid of more refined models for the soil-structure system

  14. Lessons learned from full-scale vibration tests on nuclear power plant auxiliary structure in Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Berger, E [Basler and Hofmann AG, Consulting Engineers, Zurich (Switzerland); Tinic, S [Nordostschweizerische Kraftwerke AG, Baden (Switzerland)

    1988-07-01

    The Beznau Nuclear Power Plant is located in northern Switzerland. The plant is owned and operated by the Nordostschweizerische Kraftwerke AG (NOK) in Baden, Switzerland. It is a twin unit plant (2 x 350 MWe) which was designed in the early 1960's and placed into commercial operation between 1969 and 1971. In connection with a major backfit project, which will improve the safety of the plant against external events, the free-standing boric water tanks had to be relocated and were replaced by two boric water tanks in a new building (the so called BOTA-building). It enabled to plan and perform full scale vibration tests.The scope of experimental investigation was to determine the eigenfrequencies and damping values for fundamental soil-structure interaction. The vibration tests allowed identification of the important modes of the soil-structure system in the range 3 to 15 Hz. The excitation was strung enough to generate accelerations in the structure comparable to those of a small earthquake. From the comparisons of computed and measured results it is concluded that the rocking frequency can be reasonably well predicted by either Finite Element or Lumped Parameter models with springs simulating the soil-foundation stiffness, provided in the case of the latter the embedment is taken into account. The prediction of the amplitude of structural response appears to be more difficult, as shown by the differences in the mode shapes. In the frequency range 8 to 10 Hz the agreement between computed and test results was less satisfactory. The actual structural behaviour turned out to be more complex than expected and needs further investigation with the aid of more refined models for the soil-structure system.

  15. Lateral control required for satisfactory flying qualities based on flight tests of numerous airplanes

    Science.gov (United States)

    Gilruth, R R; Turner, W N

    1941-01-01

    Report presents the results of an analysis made of the aileron control characteristics of numerous airplanes tested in flight by the National Advisory Committee for Aeronautics. By the use of previously developed theory, the observed values of pb/2v for the various wing-aileron arrangements were examined to determine the effective section characteristics of the various aileron types.

  16. ASKA STOL research aircraft flight tests and evaluation. STOL jikkenki Asuka'' no hiko shiken kekka

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, M; Inoue, T; Tobinaga, Y; Tsuji, H [Kawasaki Heavy Industries, Ltd., Tokyo (Japan)

    1991-07-20

    The present report evaluated the powered high-lift device (PHLD) distance of upper surface blowing (USB) system, basing the materialization of short distance take-off and landing (STOL) performance, one of the main flight test purposes by the Aska'', quiet STOL research aircraft, which evaluation was then added with reporting its flight test result to cover several topics. As prototypical, a C-1 tactical transport aircraft produced by Kawasaki Heavy Industries was modified to the aska'' together with the following change in design for the STOL flight test: Adoption was made of a PHLD of USB system where the wing surface was mounted with four turbofan jet engines thereon. Application was made of a boundary layer control (BLC) to the main wing leading edge and aileron. Mounting was made of a stability and control augmentation system (SCAS) using a triple system digital computer. Fitting was made of a vortex generator for the prevention from peeling by jet exhaust. As a result of flight test, the recorded distance was confirmed to be 1580ft in landing and 1670ft in take-off. 5 refs., 15 figs., 2 tabs.

  17. Aerodynamic and Acoustic Flight Test Results for the Stratospheric Observatory for Infrared Astronomy

    Science.gov (United States)

    Cumming, Stephen B.; Cliatt, Larry James; Frederick, Michael A.; Smith, Mark S.

    2013-01-01

    As part of the Stratospheric Observatory for Infrared Astronomy (SOFIA) program, a 747SP airplane was modified to carry a 2.5 meter telescope in the aft section of the fuselage. The resulting airborne observatory allows for observations above 99 percent of the water vapor in the atmosphere. The open cavity created by the modifications had the potential to significantly affect the airplane in the areas of aerodynamics and acoustics. Several series of flight tests were conducted to clear the airplanes operating envelope for astronomical observations, planned to be performed between the altitudes of 39,000 feet and 45,000 feet. The flight tests were successfully completed. Cavity acoustics were below design limits, and the overall acoustic characteristics of the cavity were better than expected. The modification did have some effects on the stability and control of the airplane, but these effects were not significant. Airplane air data systems were not affected by the modifications. This paper describes the methods used to examine the aerodynamics and acoustic data from the flight tests and provides a discussion of the flight test results in the areas of cavity acoustics, stability and control, and air data.

  18. Aerodynamic and Acoustic Flight Test Results and Results for the Stratospheric Observatory for Infrared Astronomy

    Science.gov (United States)

    Cumming, Stephen B.; Smith, Mark S.; Cliatt, Larry J.; Frederick, Michael A.

    2014-01-01

    As part of the Stratospheric Observatory for Infrared Astronomy program, a 747SP airplane was modified to carry a 2.5-m telescope in the aft section of the fuselage. The resulting airborne observatory allows for observations above 99 percent of the water vapor in the atmosphere. The open cavity created by the modifications had the potential to significantly affect the airplane in the areas of aerodynamics and acoustics. Several series of flight tests were conducted to clear the operating envelope of the airplane for astronomical observations, planned to be performed between the altitudes of 35,000 ft and 45,000 ft. The flight tests were successfully completed. Cavity acoustics were below design limits, and the overall acoustic characteristics of the cavity were better than expected. The modification did have some effects on the stability and control of the airplane, but these effects were not significant. Airplane air data systems were not affected by the modifications. This paper describes the methods used to examine the aerodynamics and acoustic data from the flight tests and provides a discussion of the flight-test results in the areas of cavity acoustics, stability and control, and air data.

  19. Development, test and flight results of the rf systems for the yes2 tether experiment

    NARCIS (Netherlands)

    Cucarella, Guillermina Castillejo; Cichocki, Andrzej; Burla, M.

    2008-01-01

    This paper highlights design, realization, testing and flight results of the Radio Frequency developments (RF) for ESA's second Young Engineers' Satellite (YES2), that included GPS systems, an intersatellite UHF link and a re-entry capsule telemetry and recovery system. The YES2 piggybacked on the

  20. Normobaric hypoxia inhalation test vs. response to airline flight in healthy passengers.

    Science.gov (United States)

    Kelly, Paul T; Swanney, Maureen P; Frampton, Chris; Seccombe, Leigh M; Peters, Matthew J; Beckert, Lutz E

    2006-11-01

    There is little data available to determine the normal response to normobaric hypoxia inhalation testing (NHIT) and air travel. Quantifying a healthy response may assist in the evaluation of passengers considered at risk for air travel. The aims of this study were: (1) to quantify the degree of desaturation in healthy subjects during a NHIT and air travel; and (2) assess the validity of the NHIT when compared with actual in-flight responses. There were 15 healthy adults (age 23-57; 10 women) who volunteered for this study. Preflight tests included lung function, arterial blood gas, pulse oximetry (SpO2), and NHIT (inspired oxygen 15%). SpO2 and cabin pressure were measured continuously on each subject during a commercial air flight (mean cabin altitude 2178 m; range 1719-2426 m). In-flight oxygenation was compared with the preflight NHIT. Lung function testing results were normal. There was significant desaturation (SpO2) during the NHIT (pre: 98 +/- 2%; post: 92 +/- 2%) and at cruising altitude (pre: 97 +/- 1%; cruise: 92 +/- 2%). There was no difference between the final NHIT SpO2 and the mean in-flight SpO2. There was a significant difference between the lowest in-flight SpO2 (88 +/- 2%) vs. the lowest NHIT SpO2, (90 +/- 2%). Oxygen saturation decreases significantly during air travel in normal individuals. In this group of healthy passengers the NHIT approximates some, but not all, aspects of in-flight oxygenation. These results can be used to describe a normal response to the NHIT and air-travel.

  1. Railway testing using a portable ride quality and vibration measurement system with GPS

    Science.gov (United States)

    Mee, Brian; Whitten, Brian; Neijikovsky, Boris

    1995-06-01

    To conduct the testing and evaluation of railway and railway vehicles, the Federal Railroad Administration developed a protable system that consists of accelerometers oriented in the vertical and horizontal directions, a Global Positioning System (GPS) receiver, data collection and power systems, and a portable computer. Commercial software was used to collect and display the data, while software, developed by ENSCO, was used to analyze and display results. The GPS provided dynamic location to an accuracy of 30 meters or better, and vehicle speed to within one mile per hour. The system was used in the demonstration tests of several advanced high-speed trains on Amtrak's Northeast Corrider and on other tracks in the US. The portable measurement system proved to be a simple and effective device to characterize the vibration environment of any transportation system. It is ideal for use in the assessment of the safe performance of high-speed trains operating at high cant deficiency. The system has also been used for other field tests, including braking performance and bridge monitoring. This report discusses the portable measurement system, the test applications that the system has been used for, the results of thoses tests, and the potential for improvements.

  2. Refinement of finite element model of a power plant by Ambient Vibration Test using system identification

    International Nuclear Information System (INIS)

    Murnal, Pranesh; Kotalwar, Sandip; Ramarao, A.; Sinha, S.K.; Singh, U.P.

    2008-01-01

    Finite Element Modeling is one of the efficient analytical tools for analysis of complicated structures subjected to variety of loads. However the reliability of the analyses is always questionable due to idealizations and assumptions made in the design. The model can be more realistic if it is refined based on experimental support. This paper presents refinement of finite-element model of Koyna Dam-foot Power House (KDPH) building, which is structurally complicated and asymmetrical. The dynamic properties of the building have been identified experimentally through Ambient Vibration Tests (AVT). The building has also been elaborately modeled analytically. The finite-element model is further refined so as to minimize the differences between analytical and the measured natural frequency of the building. The final refined finite-element model of KDPH building is able to produce natural frequency in good agreement with the measured natural frequency of the building. (author)

  3. Shuttle Return-to-Flight IH-108 Aerothermal Test at CUBRC - Flow Field Calibration and CFD

    Science.gov (United States)

    Lau, Kei Y.; Holden, M. S.

    2011-01-01

    This paper discusses one specific aspect of the Shuttle Retrun-To-Flight IH-108 Aerothermal Test at Calspan-University of Buffalo Research Center (CUBRC), the test flow field calibration. It showed the versatility of the CUBRC Large Energy National Shock Tunnel (LENS) II wind tunnel for an aerothermal test with unique and demanding requirements. CFD analyses were used effectively to extend the test range at the low end of the Mach range. It demonstrated how ground test facility and CFD synergy can be utilitzed iteratively to enhance the confidence in the fedility of both tools. It addressed the lingering concerns of the aerothermal community on use of inpulse facility and CFD analysis. At the conclusion of the test program, members from the NASA Marshall (MSFC), CUBRC and USA (United Space Alliance) Consultants (The Grey Beards) were asked to independently verify the flight scaling data generated by Boeing for flight certification of the re-designed external tank (ET) components. The blind test comparison showed very good results.

  4. Development of Flight-Test Performance Estimation Techniques for Small Unmanned Aerial Systems

    Science.gov (United States)

    McCrink, Matthew Henry

    This dissertation provides a flight-testing framework for assessing the performance of fixed-wing, small-scale unmanned aerial systems (sUAS) by leveraging sub-system models of components unique to these vehicles. The development of the sub-system models, and their links to broader impacts on sUAS performance, is the key contribution of this work. The sub-system modeling and analysis focuses on the vehicle's propulsion, navigation and guidance, and airframe components. Quantification of the uncertainty in the vehicle's power available and control states is essential for assessing the validity of both the methods and results obtained from flight-tests. Therefore, detailed propulsion and navigation system analyses are presented to validate the flight testing methodology. Propulsion system analysis required the development of an analytic model of the propeller in order to predict the power available over a range of flight conditions. The model is based on the blade element momentum (BEM) method. Additional corrections are added to the basic model in order to capture the Reynolds-dependent scale effects unique to sUAS. The model was experimentally validated using a ground based testing apparatus. The BEM predictions and experimental analysis allow for a parameterized model relating the electrical power, measurable during flight, to the power available required for vehicle performance analysis. Navigation system details are presented with a specific focus on the sensors used for state estimation, and the resulting uncertainty in vehicle state. Uncertainty quantification is provided by detailed calibration techniques validated using quasi-static and hardware-in-the-loop (HIL) ground based testing. The HIL methods introduced use a soft real-time flight simulator to provide inertial quality data for assessing overall system performance. Using this tool, the uncertainty in vehicle state estimation based on a range of sensors, and vehicle operational environments is

  5. Guidelines of the Design of Electropyrotechnic Firing Circuit for Unmanned Flight and Ground Test Projects

    Science.gov (United States)

    Gonzalez, Guillermo A.; Lucy, Melvin H.; Massie, Jeffrey J.

    2013-01-01

    The NASA Langley Research Center, Engineering Directorate, Electronic System Branch, is responsible for providing pyrotechnic support capabilities to Langley Research Center unmanned flight and ground test projects. These capabilities include device selection, procurement, testing, problem solving, firing system design, fabrication and testing; ground support equipment design, fabrication and testing; checkout procedures and procedure?s training to pyro technicians. This technical memorandum will serve as a guideline for the design, fabrication and testing of electropyrotechnic firing systems. The guidelines will discuss the entire process beginning with requirements definition and ending with development and execution.

  6. Research on computer aided testing of pilot response to critical in-flight events

    Science.gov (United States)

    Giffin, W. C.; Rockwell, T. H.; Smith, P. J.

    1984-01-01

    Experiments on pilot decision making are described. The development of models of pilot decision making in critical in flight events (CIFE) are emphasized. The following tests are reported on the development of: (1) a frame system representation describing how pilots use their knowledge in a fault diagnosis task; (2) assessment of script norms, distance measures, and Markov models developed from computer aided testing (CAT) data; and (3) performance ranking of subject data. It is demonstrated that interactive computer aided testing either by touch CRT's or personal computers is a useful research and training device for measuring pilot information management in diagnosing system failures in simulated flight situations. Performance is dictated by knowledge of aircraft sybsystems, initial pilot structuring of the failure symptoms and efficient testing of plausible causal hypotheses.

  7. Ares-I-X Stability and Control Flight Test: Analysis and Plans

    Science.gov (United States)

    Brandon, Jay M.; Derry, Stephen D.; Heim, Eugene H.; Hueschen, Richard M.; Bacon, Barton J.

    2008-01-01

    The flight test of the Ares I-X vehicle provides a unique opportunity to reduce risk of the design of the Ares I vehicle and test out design, math modeling, and analysis methods. One of the key features of the Ares I design is the significant static aerodynamic instability coupled with the relatively flexible vehicle - potentially resulting in a challenging controls problem to provide adequate flight path performance while also providing adequate structural mode damping and preventing adverse control coupling to the flexible structural modes. Another challenge is to obtain enough data from the single flight to be able to conduct analysis showing the effectiveness of the controls solutions and have data to inform design decisions for Ares I. This paper will outline the modeling approaches and control system design to conduct this flight test, and also the system identification techniques developed to extract key information such as control system performance (gain/phase margins, for example), structural dynamics responses, and aerodynamic model estimations.

  8. Pitch control margin at high angle of attack - Quantitative requirements (flight test correlation with simulation predictions)

    Science.gov (United States)

    Lackey, J.; Hadfield, C.

    1992-01-01

    Recent mishaps and incidents on Class IV aircraft have shown a need for establishing quantitative longitudinal high angle of attack (AOA) pitch control margin design guidelines for future aircraft. NASA Langley Research Center has conducted a series of simulation tests to define these design guidelines. Flight test results have confirmed the simulation studies in that pilot rating of high AOA nose-down recoveries were based on the short-term response interval in the forms of pitch acceleration and rate.

  9. Active vibration control testing of the SPICES program: final demonstration article

    Science.gov (United States)

    Dunne, James P.; Jacobs, Jack H.

    1996-05-01

    The Synthesis and Processing of Intelligent Cost Effective Structures (SPICES) Program is a partnership program sponsored by the Advanced Research Projects Agency. The mission of the program is to develop cost effective material processing and synthesis technologies to enable new products employing active vibration suppression and control devices to be brought to market. The two year program came to fruition in 1995 through the fabrication of the final smart components and testing of an active plate combined with two trapezoidal rails, forming an active mount. Testing of the SPICES combined active mount took place at McDonnell Douglas facilities in St. Louis, MO, in October-December 1995. Approximately 15 dB reduction in overall response of a motor mounted on the active structure was achieved. Further details and results of the SPICES combined active mount demonstration testing are outlined. Results of numerous damping and control strategies that were developed and employed in the testing are presented, as well as aspects of the design and fabrication of the SPICES active mount components.

  10. Full scale vibration test on nuclear power plant auxiliary building: Part I

    International Nuclear Information System (INIS)

    Langer, V.; Tinic, S.; Berger, E.; Zwicky, P.; Prater, E.G.

    1987-01-01

    In connection with the construction of the reinforced concrete auxiliary building housing the two boric water tanks (so-called BOTA building) of the Beznau Nuclear Power Plant in Switzerland the opportunity was given to carry out full scale vibration tests in November 1985. The overall aim of the tests was to validate computational models and parameters widely used in the seismic analysis of the structures and critical components of nuclear power plants. The scope of the experimental investigation was the determination of the eigenfrequencies and damping values for the fundamental soil-structure interaction (SSI) modes. The excitation level was aimed to be as high as feasibly possible. A working group was formed of representatives of the owner, NOK, the consulting firm Basler and Hofmann and the ETH to supervise the project. The project's main phases were the planning and execution of the tests, the evaluation of recorded data, numerical simulation of the tests using different computer models and finally the comparison and interpretation of measured and computed results

  11. Synthesis of Sine-on-Random vibration profiles for accelerated life tests based on fatigue damage spectrum equivalence

    Science.gov (United States)

    Angeli, Andrea; Cornelis, Bram; Troncossi, Marco

    2018-03-01

    In many real life environments, mechanical and electronic systems are subjected to vibrations that may induce dynamic loads and potentially lead to an early failure due to fatigue damage. Thus, qualification tests by means of shakers are advisable for the most critical components in order to verify their durability throughout the entire life cycle. Nowadays the trend is to tailor the qualification tests according to the specific application of the tested component, considering the measured field data as reference to set up the experimental campaign, for example through the so called "Mission Synthesis" methodology. One of the main issues is to define the excitation profiles for the tests, that must have, besides the (potentially scaled) frequency content, also the same damage potential of the field data despite being applied for a limited duration. With this target, the current procedures generally provide the test profile as a stationary random vibration specified by a Power Spectral Density (PSD). In certain applications this output may prove inadequate to represent the nature of the reference signal, and the procedure could result in an unrealistic qualification test. For instance when a rotating part is present in the system the component under analysis may be subjected to Sine-on-Random (SoR) vibrations, namely excitations composed of sinusoidal contributions superimposed to random vibrations. In this case, the synthesized test profile should preserve not only the induced fatigue damage but also the deterministic components of the environmental vibration. In this work, the potential advantages of a novel procedure to synthesize SoR profiles instead of PSDs for qualification tests are presented and supported by the results of an experimental campaign.

  12. Urban vibrations

    DEFF Research Database (Denmark)

    Morrison, Ann; Knudsen, L.; Andersen, Hans Jørgen

    2012-01-01

    In   this   paper   we   describe   a   field   study   conducted   with   a   wearable   vibration   belt   where   we   test   to   determine   the   vibration   intensity   sensitivity   ranges   on   a   large   diverse   group   of   participants   with   evenly   distributed  ages  and...

  13. Control method for multi-input multi-output non-Gaussian random vibration test with cross spectra consideration

    Directory of Open Access Journals (Sweden)

    Ronghui ZHENG

    2017-12-01

    Full Text Available A control method for Multi-Input Multi-Output (MIMO non-Gaussian random vibration test with cross spectra consideration is proposed in the paper. The aim of the proposed control method is to replicate the specified references composed of auto spectral densities, cross spectral densities and kurtoses on the test article in the laboratory. It is found that the cross spectral densities will bring intractable coupling problems and induce difficulty for the control of the multi-output kurtoses. Hence, a sequential phase modification method is put forward to solve the coupling problems in multi-input multi-output non-Gaussian random vibration test. To achieve the specified responses, an improved zero memory nonlinear transformation is utilized first to modify the Fourier phases of the signals with sequential phase modification method to obtain one frame reference response signals which satisfy the reference spectra and reference kurtoses. Then, an inverse system method is used in frequency domain to obtain the continuous stationary drive signals. At the same time, the matrix power control algorithm is utilized to control the spectra and kurtoses of the response signals further. At the end of the paper, a simulation example with a cantilever beam and a vibration shaker test are implemented and the results support the proposed method very well. Keywords: Cross spectra, Kurtosis control, Multi-input multi-output, Non-Gaussian, Random vibration test

  14. Farfield Ion Current Density Measurements before and after the NASA HiVHAc EDU2 Vibration Test

    Science.gov (United States)

    Huang, Wensheng; Kamhawi, Hani; Shastry, Rohit

    2012-01-01

    There is an increasing need to characterize the plasma plume of the NASA HiVHAc thruster in order to better understand the plasma physics and to obtain data for spacecraft interaction studies. To address this need, the HiVHAc research team is in the process of developing a number of plume diagnostic systems. This paper presents the initial results of the farfield current density probe diagnostic system. Farfield current density measurements were carried out before and after a vibration test of the HiVHAc engineering development unit 2 that simulate typical launch conditions. The main purposes of the current density measurements were to evaluate the thruster plume divergence and to investigate any changes in the plasma plume that may occur as a result of the vibration test. Radial sweeps, as opposed to the traditional polar sweeps, were performed during these tests. The charged-weighted divergence angles were found to vary from 16 to 28 degrees. Charge density profiles measured pre- and post-vibration-test were found to be in excellent agreement. This result, alongside thrust measurements reported in a companion paper, confirm that the operation of the HiVHAc engineering development unit 2 were not altered by full-level/random vibration testing.

  15. SEXTANT X-Ray Pulsar Navigation Demonstration: Flight System and Test Results

    Science.gov (United States)

    Winternitz, Luke; Mitchell, Jason W.; Hassouneh, Munther A.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven; hide

    2016-01-01

    The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology demonstration enhancement to the Neutron-star Interior Composition Explorer (NICER) mission. NICER is a NASA Explorer Mission of Opportunity that will be hosted on the International Space Station (ISS). SEXTANT will, for the first time, demonstrate real-time, on-board X-ray Pulsar Navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. This paper gives an overview of the SEXTANT system architecture and describes progress prior to environmental testing of the NICER flight instrument. It provides descriptions and development status of the SEXTANT flight software and ground system, as well as detailed description and results from the flight software functional and performance testing within the high-fidelity Goddard Space Flight Center (GSFC) X-ray Navigation Laboratory Testbed (GXLT) software and hardware simulation environment. Hardware-in-the-loop simulation results are presented, using the engineering model of the NICER timing electronics and the GXLT pulsar simulator-the GXLT precisely controls NASA GSFC's unique Modulated X-ray Source to produce X-rays that make the NICER detector electronics appear as if they were aboard the ISS viewing a sequence of millisecond pulsars

  16. Flight Test Experience With an Electromechanical Actuator on the F-18 Systems Research Aircraft

    Science.gov (United States)

    Jensen, Stephen C.; Jenney, Gavin D.; Raymond, Bruce; Dawson, David

    2000-01-01

    Development of reliable power-by-wire actuation systems for both aeronautical and space applications has been sought recently to eliminate hydraulic systems from aircraft and spacecraft and thus improve safety, efficiency, reliability, and maintainability. The Electrically Powered Actuation Design (EPAD) program was a joint effort between the Air Force, Navy, and NASA to develop and fly a series of actuators validating power-by-wire actuation technology on a primary flight control surface of a tactical aircraft. To achieve this goal, each of the EPAD actuators was installed in place of the standard hydraulic actuator on the left aileron of the NASA F/A-18B Systems Research Aircraft (SRA) and flown throughout the SRA flight envelope. Numerous parameters were recorded, and overall actuator performance was compared with the performance of the standard hydraulic actuator on the opposite wing. This paper discusses the integration and testing of the EPAD electromechanical actuator (EMA) on the SRA. The architecture of the EMA system is discussed, as well as its integration with the F/A-18 Flight Control System. The flight test program is described, and actuator performance is shown to be very close to that of the standard hydraulic actuator it replaced. Lessons learned during this program are presented and discussed, as well as suggestions for future research.

  17. Space Station Environmental Control and Life Support System Test Facility at Marshall Space Flight Center

    Science.gov (United States)

    Springer, Darlene

    1989-01-01

    Different aspects of Space Station Environmental Control and Life Support System (ECLSS) testing are currently taking place at Marshall Space Flight Center (MSFC). Unique to this testing is the variety of test areas and the fact that all are located in one building. The north high bay of building 4755, the Core Module Integration Facility (CMIF), contains the following test areas: the Subsystem Test Area, the Comparative Test Area, the Process Material Management System (PMMS), the Core Module Simulator (CMS), the End-use Equipment Facility (EEF), and the Pre-development Operational System Test (POST) Area. This paper addresses the facility that supports these test areas and briefly describes the testing in each area. Future plans for the building and Space Station module configurations will also be discussed.

  18. Vortex-Induced Vibration Tests of a Marine Growth Wrapped Cylinder at Subcritical Reynolds Number

    Directory of Open Access Journals (Sweden)

    Kurian V. J.

    2017-01-01

    Full Text Available Vortex Induced Vibrations (VIV may cause great damage to deep water risers. Estimation of accurate hydrodynamic coefficients and response amplitudes for fouled tubular cylinders subjected to VIVs is a complex task. This paper presents the results of an extensive experimental investigation on in-line and cross-flow forces acting on cylinders wrapped with marine growth, subjected to current at Subcritical Reynolds Number. The drag and lift force coefficients have been determined through the use of the Fast Fourier Analysis methods. The different tests were conducted in the offshore engineering laboratory at Universiti Teknologi PETRONAS (UTP, Malaysia. In this study, a cylinder with outer diameter Do = 27 mm, fixed at top as cantilever beam was used. The in-line and cross-flow forces were measured using VIV Force Totaller (VIVFT. VIVFT is a two degree of freedom (2DOF forces sensor developed by UTP to measure the VIV forces. The tests were conducted for current velocity varied between 0.118 to 0.59 m/s. The test results suggest that the cylinder wrapped with marine growth has shown an overall increase in drag and inertia coefficients as well as on response amplitudes.

  19. Implementation and flight-test of a multi-mode rotorcraft flight-control system for single-pilot use in poor visibility

    Science.gov (United States)

    Hindson, William S.

    1987-01-01

    A flight investigation was conducted to evaluate a multi-mode flight control system designed according to the most recent recommendations for handling qualities criteria for new military helicopters. The modes and capabilities that were included in the system are those considered necessary to permit divided-attention (single-pilot) lowspeed and hover operations near the ground in poor visibility conditions. Design features included mode-selection and mode-blending logic, the use of an automatic position-hold mode that employed precision measurements of aircraft position, and a hover display which permitted manually-controlled hover flight tasks in simulated instrument conditions. Pilot evaluations of the system were conducted using a multi-segment evaluation task. Pilot comments concerning the use of the system are provided, and flight-test data are presented to show system performance.

  20. A Description of the Software Element of the NASA EME Flight Tests

    Science.gov (United States)

    Koppen, Sandra V.

    1996-01-01

    In support of NASA's Fly-By-Light/Power-By-Wire (FBL/PBW) program, a series of flight tests were conducted by NASA Langley Research Center in February, 1995. The NASA Boeing 757 was flown past known RF transmitters to measure both external and internal radiated fields. The aircraft was instrumented with strategically located sensors for acquiring data on shielding effectiveness and internal coupling. The data are intended to support computational and statistical modeling codes used to predict internal field levels of an electromagnetic environment (EME) on aircraft. The software was an integral part of the flight tests, as well as the data reduction process. The software, which provided flight test instrument control, data acquisition, and a user interface, executes on a Hewlett Packard (HP) 300 series workstation and uses BP VEEtest development software and the C programming language. Software tools were developed for data processing and analysis, and to provide a database organized by frequency bands, test runs, and sensors. This paper describes the data acquisition system on board the aircraft and concentrates on the software portion. Hardware and software interfaces are illustrated and discussed. Particular attention is given to data acquisition and data format. The data reduction process is discussed in detail to provide insight into the characteristics, quality, and limitations of the data. An analysis of obstacles encountered during the data reduction process is presented.

  1. Modeling and Closed Loop Flight Testing of a Fixed Wing Micro Air Vehicle

    Directory of Open Access Journals (Sweden)

    Harikumar Kandath

    2018-03-01

    Full Text Available This paper presents the nonlinear six degrees of freedom dynamic modeling of a fixed wing micro air vehicle. The static derivatives of the micro air vehicle are obtained through the wind tunnel testing. The propeller effects on the lift, drag, pitching moment and side force are quantified through wind tunnel testing. The dynamic derivatives are obtained through empirical relations available in the literature. The trim conditions are computed for a straight and constant altitude flight condition. The linearized longitudinal and lateral state space models are obtained about trim conditions. The variations in short period mode, phugoid mode, Dutch roll mode, roll subsidence mode and spiral mode with respect to different trim operating conditions is presented. A stabilizing static output feedback controller is designed using the obtained model. Successful closed loop flight trials are conducted with the static output feedback controller.

  2. Flight Flutter Testing of Rotary Wing Aircraft Using a Control System Oscillation Technique

    Science.gov (United States)

    Yen, J. G.; Viswanathan, S.; Matthys, C. G.

    1976-01-01

    A flight flutter testing technique is described in which the rotor controls are oscillated by series actuators to excite the rotor and airframe modes of interest, which are then allowed to decay. The moving block technique is then used to determine the damped frequency and damping variation with rotor speed. The method proved useful for tracking the stability of relatively well damped modes. The results of recently completed flight tests of an experimental soft-in-plane rotor are used to illustrate the technique. Included is a discussion of the application of this technique to investigation of the propeller whirl flutter stability characteristics of the NASA/Army XV-15 VTOL tilt rotor research aircraft.

  3. Analysis of crack initiation and growth in the high level vibration test at Tadotsu

    International Nuclear Information System (INIS)

    Kassir, M.K.; Hofmayer, C.H.; Bandyopadhyay, K.K.

    1991-01-01

    A High Level Vibration Test (HLVT) Program was carried out recently on the seismic table at the Tadotsu Engineering Laboratory of Nuclear Power Engineering Center (NUPEC) in Japan. The objective of the study being performed at Brookhaven National Laboratory is to use the HLVT data to assess the accuracy and usefulness of existing methods for predicting crack initiation and growth under complex, large amplitude loading. The work to be performed as part of this effort involves: (1) analysis of the stress/strain distribution in the vicinity of the crack, including the potential for residual stresses due to the weld repair; (2) analysis of the number of load cycles required for crack initiation, including estimates of the impact of the weld repair on the crack initiation behavior; (3) analysis of crack advance as a function of applied loading (classic fatigue versus cyclic tearing) taking into account the variable amplitude loading and the possible influence of the repair; and (4) material property testing to supplement the work performed as part of the HLVT, providing the materials data necessary to perform the analysis efforts. A summary of research progress for FY 1990 is presented. 2 refs

  4. Orion Exploration Flight Test 1 (EFT-1) Best Estimated Trajectory Development

    Science.gov (United States)

    Holt, Greg N.; Brown, Aaron

    2016-01-01

    The Orion Exploration Flight Test 1 (EFT-1) mission successfully flew on Dec 5, 2014 atop a Delta IV Heavy launch vehicle. The goal of Orions maiden flight was to stress the system by placing an uncrewed vehicle on a high-energy trajectory replicating conditions similar to those that would be experienced when returning from an asteroid or a lunar mission. The Orion navigation team combined all trajectory data from the mission into a Best Estimated Trajectory (BET) product. There were significant challenges in data reconstruction and many lessons were learned for future missions. The team used an estimation filter incorporating radar tracking, onboard sensors (Global Positioning System and Inertial Measurement Unit), and day-of-flight weather balloons to evaluate the true trajectory flown by Orion. Data was published for the entire Orion EFT-1 flight, plus objects jettisoned during entry such as the Forward Bay Cover. The BET customers include approximately 20 disciplines within Orion who will use the information for evaluating vehicle performance and influencing future design decisions.

  5. Flight-Test Evaluation of Kinematic Precise Point Positioning of Small UAVs

    Directory of Open Access Journals (Sweden)

    Jason N. Gross

    2016-01-01

    Full Text Available An experimental analysis of Global Positioning System (GPS flight data collected onboard a Small Unmanned Aerial Vehicle (SUAV is conducted in order to demonstrate that postprocessed kinematic Precise Point Positioning (PPP solutions with precisions approximately 6 cm 3D Residual Sum of Squares (RSOS can be obtained on SUAVs that have short duration flights with limited observational periods (i.e., only ~≤5 minutes of data. This is a significant result for the UAV flight testing community because an important and relevant benefit of the PPP technique over traditional Differential GPS (DGPS techniques, such as Real-Time Kinematic (RTK, is that there is no requirement for maintaining a short baseline separation to a differential GNSS reference station. Because SUAVs are an attractive platform for applications such as aerial surveying, precision agriculture, and remote sensing, this paper offers an experimental evaluation of kinematic PPP estimation strategies using SUAV platform data. In particular, an analysis is presented in which the position solutions that are obtained from postprocessing recorded UAV flight data with various PPP software and strategies are compared to solutions that were obtained using traditional double-differenced ambiguity fixed carrier-phase Differential GPS (CP-DGPS. This offers valuable insight to assist designers of SUAV navigation systems whose applications require precise positioning.

  6. Use of a Commercially Available Flight Simulator during Aircrew Performance Testing.

    Science.gov (United States)

    1991-11-01

    Automiated Battery of Performance-based Tests, NAMRL 1354, Naval Aerospace Medical Research Laboratory, Pensacola, FL, 1990. 13. Human Performance...ability of an aircraft to remain airborne well beyond the limits of its human operator. This capacity for longer flights, coupled with a tendency for short...Measurement, Final Report, Air Force Human Resources Laboratory, Brooks AFB, TX, 1983. 5. Stein, E.S., Measurement of Pilot Performance: A Master Journeyman

  7. Laminar and Turbulent Flow Calculations for the Hifire-5B Flight Test

    Science.gov (United States)

    2017-11-01

    STATES AIR FORCE AFRL-RQ-WP-TP-2017-0172 LAMINAR AND TURBULENT FLOW CALCULATIONS FOR THE HIFIRE-5B FLIGHT TEST Roger L. Kimmel Hypersonic Sciences...stationary instabilities of the three-dimensional flow as the grid becomes finer. It may not be possible to obtain a strictly laminar basic state on a very...fine grid. A basic state solution was desired for the laminar flow calculations, and the oscillations observed in Fig. 3 were judged to be undesirable

  8. Flight Test Results from the NF-15B Intelligent Flight Control System (IFCS) Project with Adaptation to a Simulated Stabilator Failure

    Science.gov (United States)

    Bosworth, John T.; Williams-Hayes, Peggy S.

    2010-01-01

    Adaptive flight control systems have the potential to be more resilient to extreme changes in airplane behavior. Extreme changes could be a result of a system failure or of damage to the airplane. A direct adaptive neural-network-based flight control system was developed for the National Aeronautics and Space Administration NF-15B Intelligent Flight Control System airplane and subjected to an inflight simulation of a failed (frozen) (unmovable) stabilator. Formation flight handling qualities evaluations were performed with and without neural network adaptation. The results of these flight tests are presented. Comparison with simulation predictions and analysis of the performance of the adaptation system are discussed. The performance of the adaptation system is assessed in terms of its ability to decouple the roll and pitch response and reestablish good onboard model tracking. Flight evaluation with the simulated stabilator failure and adaptation engaged showed that there was generally improvement in the pitch response; however, a tendency for roll pilot-induced oscillation was experienced. A detailed discussion of the cause of the mixed results is presented.

  9. Evaluation of climatic vibration testing on plastic waterproof enclosure for electronic equipment using ANSYS[reg] workbench

    International Nuclear Information System (INIS)

    Aw, K.C.; Huang, W.D.J.; De Silva, M.W.R.P.

    2007-01-01

    Designing and testing of waterproof enclosure for electronic equipment involves significant amount of time and resources. This paper concentrates on electronic equipment used for maritime application. Typical waterproof test perform is based on the IEC 60529 standards and is insufficient to determine its reliability. Since, these enclosures were subjected to environmental stress such as heat and vibration and there is a need to understand how these affect the waterproof performance. Simulation using ANSYS workbench software was performed to comprehend the effect of various parameters of accelerated testing performed on these waterproof enclosures. Experiments were performed to examine the correlation with simulation results. The results confirmed that accelerated testing with random vibration at cold temperature causes greatest stress and causes degradation to adhesive bonds and hence affect the waterproof performance

  10. Functional Task Test: 3. Skeletal Muscle Performance Adaptations to Space Flight

    Science.gov (United States)

    Ryder, Jeffrey W.; Wickwire, P. J.; Buxton, R. E.; Bloomberg, J. J.; Ploutz-Snyder, L.

    2011-01-01

    The functional task test is a multi-disciplinary study investigating how space-flight induced changes to physiological systems impacts functional task performance. Impairment of neuromuscular function would be expected to negatively affect functional performance of crewmembers following exposure to microgravity. This presentation reports the results for muscle performance testing in crewmembers. Functional task performance will be presented in the abstract "Functional Task Test 1: sensory motor adaptations associated with postflight alternations in astronaut functional task performance." METHODS: Muscle performance measures were obtained in crewmembers before and after short-duration space flight aboard the Space Shuttle and long-duration International Space Station (ISS) missions. The battery of muscle performance tests included leg press and bench press measures of isometric force, isotonic power and total work. Knee extension was used for the measurement of central activation and maximal isometric force. Upper and lower body force steadiness control were measured on the bench press and knee extension machine, respectively. Tests were implemented 60 and 30 days before launch, on landing day (Shuttle crew only), and 6, 10 and 30 days after landing. Seven Space Shuttle crew and four ISS crew have completed the muscle performance testing to date. RESULTS: Preliminary results for Space Shuttle crew reveal significant reductions in the leg press performance metrics of maximal isometric force, power and total work on R+0 (pperformance metrics were observed in returning Shuttle crew and these adaptations are likely contributors to impaired functional tasks that are ambulatory in nature (See abstract Functional Task Test: 1). Interestingly, no significant changes in central activation capacity were detected. Therefore, impairments in muscle function in response to short-duration space flight are likely myocellular rather than neuromotor in nature.

  11. Portable vibration exciter

    Science.gov (United States)

    Beecher, L. C.; Williams, F. T.

    1970-01-01

    Gas-driven vibration exciter produces a sinusoidal excitation function controllable in frequency and in amplitude. It allows direct vibration testing of components under normal loads, removing the possibility of component damage due to high static pressure.

  12. Dynamic analysis and vibration testing of CFRP drive-line system used in heavy-duty machine tool

    Directory of Open Access Journals (Sweden)

    Mo Yang

    2018-03-01

    Full Text Available Low critical rotary speed and large vibration in the metal drive-line system of heavy-duty machine tool affect the machining precision seriously. Replacing metal drive-line with the CFRP drive-line can effectively solve this problem. Based on the composite laminated theory and the transfer matrix method (TMM, this paper puts forward a modified TMM to analyze dynamic characteristics of CFRP drive-line system. With this modified TMM, the CFRP drive-line of a heavy vertical miller is analyzed. And the finite element modal analysis model of the shafting is established. The results of the modified TMM and finite element analysis (FEA show that the modified TMM can effectively predict the critical rotary speed of CFRP drive-line. And the critical rotary speed of CFRP drive-line is 20% higher than that of the original metal drive-line. Then, the vibration of the CFRP and the metal drive-line were tested. The test results show that application of the CFRP drive shaft in the drive-line can effectively reduce the vibration of the heavy-duty machine tool. Keywords: CFRP drive-line system, Dynamic behavior, Transfer matrix, Vibration measurement

  13. Ocular vestibular evoked myogenic potentials to vertex low frequency vibration as a diagnostic test for superior canal dehiscence.

    Science.gov (United States)

    Verrecchia, Luca; Westin, Magnus; Duan, Maoli; Brantberg, Krister

    2016-04-01

    To explore ocular vestibular evoked myogenic potentials (oVEMP) to low-frequency vertex vibration (125 Hz) as a diagnostic test for superior canal dehiscence (SCD) syndrome. The oVEMP using 125 Hz single cycle bone-conducted vertex vibration were tested in 15 patients with unilateral superior canal dehiscence (SCD) syndrome, 15 healthy controls and in 20 patients with unilateral vestibular loss due to vestibular neuritis. Amplitude, amplitude asymmetry ratio, latency and interaural latency difference were parameters of interest. The oVEMP amplitude was significantly larger in SCD patients when affected sides (53 μVolts) were compared to non-affected (17.2 μVolts) or compared to healthy controls (13.6 μVolts). Amplitude larger than 33.8 μVolts separates effectively the SCD ears from the healthy ones with sensitivity of 87% and specificity of 93%. The other three parameters showed an overlap between affected SCD ears and non-affected as well as between SCD ears and those in the two control groups. oVEMP amplitude distinguishes SCD ears from healthy ones using low-frequency vibration stimuli at vertex. Amplitude analysis of oVEMP evoked by low-frequency vertex bone vibration stimulation is an additional indicator of SCD syndrome and might serve for diagnosing SCD patients with coexistent conductive middle ear problems. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  14. Testing second order cyclostationarity in the squared envelope spectrum of non-white vibration signals

    Science.gov (United States)

    Borghesani, P.; Pennacchi, P.; Ricci, R.; Chatterton, S.

    2013-10-01

    Cyclostationary models for the diagnostic signals measured on faulty rotating machineries have proved to be successful in many laboratory tests and industrial applications. The squared envelope spectrum has been pointed out as the most efficient indicator for the assessment of second order cyclostationary symptoms of damages, which are typical, for instance, of rolling element bearing faults. In an attempt to foster the spread of rotating machinery diagnostics, the current trend in the field is to reach higher levels of automation of the condition monitoring systems. For this purpose, statistical tests for the presence of cyclostationarity have been proposed during the last years. The statistical thresholds proposed in the past for the identification of cyclostationary components have been obtained under the hypothesis of having a white noise signal when the component is healthy. This need, coupled with the non-white nature of the real signals implies the necessity of pre-whitening or filtering the signal in optimal narrow-bands, increasing the complexity of the algorithm and the risk of losing diagnostic information or introducing biases on the result. In this paper, the authors introduce an original analytical derivation of the statistical tests for cyclostationarity in the squared envelope spectrum, dropping the hypothesis of white noise from the beginning. The effect of first order and second order cyclostationary components on the distribution of the squared envelope spectrum will be quantified and the effectiveness of the newly proposed threshold verified, providing a sound theoretical basis and a practical starting point for efficient automated diagnostics of machine components such as rolling element bearings. The analytical results will be verified by means of numerical simulations and by using experimental vibration data of rolling element bearings.

  15. A bandwidth correction to the Allegri-Zhang solution for accelerated random vibration testing

    Directory of Open Access Journals (Sweden)

    Benasciutti Denis

    2018-01-01

    Full Text Available In 2008, Allegri and Zhang published a study [Int. J. Fatigue. 2008, 30(6:967-977] in which they provided an exact analytical solution to the inverse scaling law for accelerated vibration tests of linear systems submitted to stationary Gaussian excitations By combining finite element analysis with multiaxial spectral methods defined in the frequency-domain, their solution generalised the simple inverse power law model suggested in some standards. The solution adopted the “equivalent von Mises stress” multiaxial criterion combined with the narrow-band damage expression. This work aims to propose a bandwidth correction to the original Allegri-Zhang solution to account for the actual spectral banwidth of the local multiaxial stress. The corrected Allegri-Zhang solution is also extended to another multiaxial spectral method, namely the “Projection-by-Projection” criterion. A numerical example is finally discussed, in which the corrected solution is applied to an L-shaped beam submitted to random accelerations.

  16. Basic performance tests on vibration of support structure with flexible plates for ITER tokamak device

    International Nuclear Information System (INIS)

    Takeda, Nobukazu; Kakudate, Satoshi; Shibanuma, Kiyoshi

    2005-01-01

    The vibration experiments of the support structures with flexible plates for the ITER major components such as toroidal field coil (TF coil) and vacuum vessel (VV) were performed using small-sized flexible plates aiming to obtain its basic mechanical characteristics such as dependence of the stiffness on the loading angle. The experimental results obtained by the hammering and frequency sweep tests were agreed each other, so that the experimental method is found to be reliable. In addition, the experimental results were compared with the analytical ones in order to estimate an adequate analytical model for ITER support structure with flexible plates. As a result, the bolt connection of the flexible plates on the base plate strongly affected on the stiffness of the flexible plates. After studies of modeling the bolts, it is found that the analytical results modeling the bolts with finite stiffness only in the axial direction and infinite stiffness in the other directions agree well with the experimental ones. Using this adequate model, the stiffness of the support structure with flexible plates for the ITER major components can be calculated precisely in order to estimate the dynamic behaviors such as eigen modes and amplitude of deformation of the major components of the ITER tokamak device. (author)

  17. Vibration analysis on driver’s seat of agricultural tractors during tillage tests

    International Nuclear Information System (INIS)

    Gialamas, T.; Gravalos, I.; Kateris, D.; Xyradakis, P.; Dimitriadis, C.

    2016-01-01

    The vibration of the driver’s seat of agricultural tractors was investigated during three alternative tillage operations. Three tractors including a range of specifications were considered, at a range of forward speeds. The interactions between the tractors, implements and speeds were examined using the SPSS program and the GLM-ANOVA method. The results analysis indicated that the tractors played the first major role in vibration development in the lateral axis and was followed by the implements. In contrast, the implements played the first major role in the development of vibration in the horizontal axis and are followed by factor tractors. The statistically significant effect in vertical and horizontal axes shows the factor implements. In addition, the statistically significant effect in the vertical and lateral axes shows again the implements to be the most significant factor. Of the implements, the plough shows the highest vibration and displays statistically significant difference in comparison with the other implements.

  18. Classification Analysis of Vibration Data from SH-60B Helicopter Transmission Test Facility

    National Research Council Canada - National Science Library

    Anderson, Gregory

    1997-01-01

    .... The system is referred to as the Health Usage and Monitoring Systems (HUMS). The program's objective is to develop an automated diagnostic system that can identify mechanical faults within the power train of helicopters using vibration analysis...

  19. Vibration tests on single heat exchanger tubes in air and static water

    International Nuclear Information System (INIS)

    Collinson, A.E.; Warneford, I.P.

    1978-07-01

    The vibrational characteristics of a 7 span straight tube and a 26 span U-tube have been investigated for the effects of fluid medium (air/water), tube-grid clearance, tube-grid contact force, vibration transmission and scale. Measured frequency response and mode shapes compared favourably with theoretical values, vibration with pin-pin tube support being most readily excited. The frequency reduction on immersion in water corresponded to an added mass equivalent to the liquid displaced mass. Dynamic magnifiers varied in the range 12 to 135 with mean values of 30 to 40 in water and 45 to 60 in air. Principal vibration modes and damping values were reproducible in a half-scale model of a U-tube. (author)

  20. Study on the application of ambient vibration tests to evaluate the effectiveness of seismic retrofitting

    Science.gov (United States)

    Liang, Li; Takaaki, Ohkubo; Guang-hui, Li

    2018-03-01

    In recent years, earthquakes have occurred frequently, and the seismic performance of existing school buildings has become particularly important. The main method for improving the seismic resistance of existing buildings is reinforcement. However, there are few effective methods to evaluate the effect of reinforcement. Ambient vibration measurement experiments were conducted before and after seismic retrofitting using wireless measurement system and the changes of vibration characteristics were compared. The changes of acceleration response spectrum, natural periods and vibration modes indicate that the wireless vibration measurement system can be effectively applied to evaluate the effect of seismic retrofitting. The method can evaluate the effect of seismic retrofitting qualitatively, it is difficult to evaluate the effect of seismic retrofitting quantitatively at this stage.

  1. Vibration analysis on driver’s seat of agricultural tractors during tillage tests

    Energy Technology Data Exchange (ETDEWEB)

    Gialamas, T.; Gravalos, I.; Kateris, D.; Xyradakis, P.; Dimitriadis, C.

    2016-07-01

    The vibration of the driver’s seat of agricultural tractors was investigated during three alternative tillage operations. Three tractors including a range of specifications were considered, at a range of forward speeds. The interactions between the tractors, implements and speeds were examined using the SPSS program and the GLM-ANOVA method. The results analysis indicated that the tractors played the first major role in vibration development in the lateral axis and was followed by the implements. In contrast, the implements played the first major role in the development of vibration in the horizontal axis and are followed by factor tractors. The statistically significant effect in vertical and horizontal axes shows the factor implements. In addition, the statistically significant effect in the vertical and lateral axes shows again the implements to be the most significant factor. Of the implements, the plough shows the highest vibration and displays statistically significant difference in comparison with the other implements.

  2. Design, construction, test and field support of a containerless payload package for rocket flight. [electromagnetic heating and confinement

    Science.gov (United States)

    1977-01-01

    The performance of a device for electromagnetically heating and positioning containerless melts during space processing was evaluated during a 360 second 0-g suborbital sounding rocket flight. Components of the electromagnetic containerless processing package (ECPP), its operation, and interface with the rocket are described along with flight and qualification tests results.

  3. Merenje vibracija i relevantnih parametara leta transportnog helikoptera Mi-8 sa revitalizovanim lopaticama nosećeg rotora / Vibration and flight data measurement on the transport helicopter Mi-8 with replaced main rotor blades

    Directory of Open Access Journals (Sweden)

    Veljko Rakonjac

    2004-11-01

    Full Text Available Rad se odnosi na merenje parametara leta transportnog helikoptera ruske proizvodnje Mi-8 sa ugrađenim originalnim, kao i revitalizovanim - delimično kompozitnim lopaticama nosećeg rotora. Cilj merenja bio je dobijanje relevantnih podataka za ocenu kvaliteta revitalizovanih lopatica usled zamene lopatica nosećeg rotora. Prikazani su oprema, postupak i analiza rezultata merenja parametara leta i vibracija, uz poseban osvrt na probleme izazvane uticajem vibracija na mernu opremu. / This paper presents helicopter flight data acquisition made on the Russian helicopter Mi-8 with its original main rotor blades as well as with regenerated, partially composite ones. The purpose of the measurement was collecting data for flight quality of the main rotor composite blades changing the actual main rotor blades. This paper also presents equipment procedures and analysis of flight data and vitration measurements with special attention to problems caused by vibration influence on equipment.

  4. Application of a flight test and data analysis technique to flutter of a drone aircraft

    Science.gov (United States)

    Bennett, R. M.

    1981-01-01

    Modal identification results presented were obtained from recent flight flutter tests of a drone vehicle with a research wing (DAST ARW-1 for Drones for Aerodynamic and Structural Testing, Aeroelastic Research Wing-1). This vehicle is equipped with an active flutter suppression system (FSS). Frequency and damping of several modes are determined by a time domain modal analysis of the impulse response function obtained by Fourier transformations of data from fast swept sine wave excitation by the FSS control surface on the wing. Flutter points are determined for two different altitudes with the FSS off. Data are given for near the flutter boundary with the FSS on.

  5. Stability and control of the Gossamer human powered aircraft by analysis and flight test

    Science.gov (United States)

    Jex, H. R.; Mitchell, D. G.

    1982-01-01

    The slow flight speed, very light wing loading, and neutral stability of the Gossamer Condor and the Gossamer Albatross emphasized apparent-mass aerodynamic effects and unusual modes of motion response. These are analyzed, approximated, and discussed, and the resulting transfer functions and dynamic properties are summarized and compared. To verify these analytical models, flight tests were conducted with and electrically powered Gossamer Albatross II. Sensors were installed and their outputs were telemetered to records on the ground. Frequency sweeps of the various controls were made and the data were reduced to frequency domain measures. Results are given for the response of: pitch rate, airspeed and normal acceleration from canard-elevator deflection; roll rate and yaw rate from canard-rudder tilt; and roll rate and yaw rate from wing warp. The reliable data are compared with the analytical predictions.

  6. STS-114: Discovery TCDT Flight Crew Test Media Event at Pad 39-B

    Science.gov (United States)

    2005-01-01

    The STS-114 Space Shuttle Discovery Terminal Countdown Demonstration Test (TCDT) flight crew is shown at Pad 39-B. Eileen Collins, Commander introduces the astronauts. Andrew Thomas, mission specialist talks about his primary responsibility of performing boom inspections, Wendy Lawrence, Mission Specialist 4 (MS4) describes her role as the robotic arm operator supporting Extravehicular Activities (EVA), Stephen Robinson, Mission Specialist 3 (MS3) talks about his role as flight engineer, Charlie Camarda, Mission Specialist 5 (MS5) says that his duties are to perform boom operations, transfer operations from the space shuttle to the International Space Station and spacecraft rendezvous. Soichi Noguchi, Mission Specialist 1 (MS1) from JAXA, introduces himself as Extravehicular Activity 1 (EVA1), and Jim Kelley, Pilot will operate the robotic arm and perform pilot duties. Questions from the news media about the safety of the external tank, going to the International Space Station and returning, EVA training, and thoughts about the Space Shuttle Columbia crew are answered.

  7. VUV testing of science cameras at MSFC: QE measurement of the CLASP flight cameras

    Science.gov (United States)

    Champey, P.; Kobayashi, K.; Winebarger, A.; Cirtain, J.; Hyde, D.; Robertson, B.; Beabout, B.; Beabout, D.; Stewart, M.

    2015-08-01

    The NASA Marshall Space Flight Center (MSFC) has developed a science camera suitable for sub-orbital missions for observations in the UV, EUV and soft X-ray. Six cameras were built and tested for the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP), a joint MSFC, National Astronomical Observatory of Japan (NAOJ), Instituto de Astrofisica de Canarias (IAC) and Institut D'Astrophysique Spatiale (IAS) sounding rocket mission. The CLASP camera design includes a frame-transfer e2v CCD57-10 512 × 512 detector, dual channel analog readout and an internally mounted cold block. At the flight CCD temperature of -20C, the CLASP cameras exceeded the low-noise performance requirements (UV, EUV and X-ray science cameras at MSFC.

  8. Orion Exploration Flight Test-l (EFT -1) Absolute Navigation Design

    Science.gov (United States)

    Sud, Jastesh; Gay, Robert; Holt, Greg; Zanetti, Renato

    2014-01-01

    Scheduled to launch in September 2014 atop a Delta IV Heavy from the Kennedy Space Center, the Orion Multi-Purpose-Crew-Vehicle (MPCV's) maiden flight dubbed "Exploration Flight Test -1" (EFT-1) intends to stress the system by placing the uncrewed vehicle on a high-energy parabolic trajectory replicating conditions similar to those that would be experienced when returning from an asteroid or a lunar mission. Unique challenges associated with designing the navigation system for EFT-1 are presented in the narrative with an emphasis on how redundancy and robustness influenced the architecture. Two Inertial Measurement Units (IMUs), one GPS receiver and three barometric altimeters (BALTs) comprise the navigation sensor suite. The sensor data is multiplexed using conventional integration techniques and the state estimate is refined by the GPS pseudorange and deltarange measurements in an Extended Kalman Filter (EKF) that employs the UDUT decomposition approach. The design is substantiated by simulation results to show the expected performance.

  9. Space Environmental Effects Testing Capability at the Marshall Space Flight Center

    Science.gov (United States)

    DeWittBurns, H.; Craven, Paul; Finckenor, Miria; Nehls, Mary; Schneider, Todd; Vaughn, Jason

    2012-01-01

    Understanding the effects of the space environment on materials and systems is fundamental and essential for mission success. If not properly understood and designed for, the effects of the environment can lead to degradation of materials, reduction of functional lifetime, and system failure. In response to this need, the Marshall Space Flight Center has developed world class Space Environmental Effects (SEE) expertise and test facilities to simulate the space environment. Capabilities include multiple unique test systems comprising the most complete SEE testing capability available. These test capabilities include charged particle radiation (electrons, protons, ions), ultraviolet radiation (UV), vacuum ultraviolet radiation (VUV), atomic oxygen, plasma effects, space craft charging, lunar surface and planetary effects, vacuum effects, and hypervelocity impacts as well as the combination of these capabilities. In addition to the uniqueness of the individual test capabilities, MSFC is the only NASA facility where the effects of the different space environments can be tested in one location. Combined with additional analytical capabilities for pre- and post-test evaluation, MSFC is a one-stop shop for materials testing and analysis. The SEE testing and analysis are performed by a team of award winning experts nationally recognized for their contributions in the study of the effects of the space environment on materials and systems. With this broad expertise in space environmental effects and the variety of test systems and equipment available, MSFC is able to customize tests with a demonstrated ability to rapidly adapt and reconfigure systems to meet customers needs. Extensive flight experiment experience bolsters this simulation and analysis capability with a comprehensive understanding of space environmental effects.

  10. Flight Testing of Night Vision Systems in Rotorcraft (Test en vol de systemes de vision nocturne a bord des aeronefs a voilure tournante)

    Science.gov (United States)

    2007-07-01

    Test Engineer GVE Good Visual Environment HMD Head Mounted Displays HQR Handling Quality Rating HUD Heads Up Display IFR Instrument Flight...may take the form of general questionnaires such as the China Lake Situational Awareness Rating Scale, the Situational Awareness Global Assessment...performed in 5-ft decrements. IFR transit flight duties should also be performed, when simulating flight in IMC. In all cases, internal lighting must

  11. Max Launch Abort System (MLAS) Pad Abort Test Vehicle (PATV) II Attitude Control System (ACS) Integration and Pressurization Subsystem Dynamic Random Vibration Analysis

    Science.gov (United States)

    Ekrami, Yasamin; Cook, Joseph S.

    2011-01-01

    In order to mitigate catastrophic failures on future generation space vehicles, engineers at the National Aeronautics and Space Administration have begun to integrate a novel crew abort systems that could pull a crew module away in case of an emergency at the launch pad or during ascent. The Max Launch Abort System (MLAS) is a recent test vehicle that was designed as an alternative to the baseline Orion Launch Abort System (LAS) to demonstrate the performance of a "tower-less" LAS configuration under abort conditions. The MLAS II test vehicle will execute a propulsive coast stabilization maneuver during abort to control the vehicles trajectory and thrust. To accomplish this, the spacecraft will integrate an Attitude Control System (ACS) with eight hypergolic monomethyl hydrazine liquid propulsion engines that are capable of operating in a quick pulsing mode. Two main elements of the ACS include a propellant distribution subsystem and a pressurization subsystem to regulate the flow of pressurized gas to the propellant tanks and the engines. The CAD assembly of the Attitude Control System (ACS) was configured and integrated into the Launch Abort Vehicle (LAV) design. A dynamic random vibration analysis was conducted on the Main Propulsion System (MPS) helium pressurization panels to assess the response of the panel and its components under increased gravitational acceleration loads during flight. The results indicated that the panels fundamental and natural frequencies were farther from the maximum Acceleration Spectral Density (ASD) vibrations which were in the range of 150-300 Hz. These values will direct how the components will be packaged in the vehicle to reduce the effects high gravitational loads.

  12. Case Study: Test Results of a Tool and Method for In-Flight, Adaptive Control System Verification on a NASA F-15 Flight Research Aircraft

    Science.gov (United States)

    Jacklin, Stephen A.; Schumann, Johann; Guenther, Kurt; Bosworth, John

    2006-01-01

    Adaptive control technologies that incorporate learning algorithms have been proposed to enable autonomous flight control and to maintain vehicle performance in the face of unknown, changing, or poorly defined operating environments [1-2]. At the present time, however, it is unknown how adaptive algorithms can be routinely verified, validated, and certified for use in safety-critical applications. Rigorous methods for adaptive software verification end validation must be developed to ensure that. the control software functions as required and is highly safe and reliable. A large gap appears to exist between the point at which control system designers feel the verification process is complete, and when FAA certification officials agree it is complete. Certification of adaptive flight control software verification is complicated by the use of learning algorithms (e.g., neural networks) and degrees of system non-determinism. Of course, analytical efforts must be made in the verification process to place guarantees on learning algorithm stability, rate of convergence, and convergence accuracy. However, to satisfy FAA certification requirements, it must be demonstrated that the adaptive flight control system is also able to fail and still allow the aircraft to be flown safely or to land, while at the same time providing a means of crew notification of the (impending) failure. It was for this purpose that the NASA Ames Confidence Tool was developed [3]. This paper presents the Confidence Tool as a means of providing in-flight software assurance monitoring of an adaptive flight control system. The paper will present the data obtained from flight testing the tool on a specially modified F-15 aircraft designed to simulate loss of flight control faces.

  13. VUV Testing of Science Cameras at MSFC: QE Measurement of the CLASP Flight Cameras

    Science.gov (United States)

    Champey, Patrick R.; Kobayashi, Ken; Winebarger, A.; Cirtain, J.; Hyde, D.; Robertson, B.; Beabout, B.; Beabout, D.; Stewart, M.

    2015-01-01

    The NASA Marshall Space Flight Center (MSFC) has developed a science camera suitable for sub-orbital missions for observations in the UV, EUV and soft X-ray. Six cameras were built and tested for the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP), a joint National Astronomical Observatory of Japan (NAOJ) and MSFC sounding rocket mission. The CLASP camera design includes a frame-transfer e2v CCD57-10 512x512 detector, dual channel analog readout electronics and an internally mounted cold block. At the flight operating temperature of -20 C, the CLASP cameras achieved the low-noise performance requirements (less than or equal to 25 e- read noise and greater than or equal to 10 e-/sec/pix dark current), in addition to maintaining a stable gain of approximately equal to 2.0 e-/DN. The e2v CCD57-10 detectors were coated with Lumogen-E to improve quantum efficiency (QE) at the Lyman- wavelength. A vacuum ultra-violet (VUV) monochromator and a NIST calibrated photodiode were employed to measure the QE of each camera. Four flight-like cameras were tested in a high-vacuum chamber, which was configured to operate several tests intended to verify the QE, gain, read noise, dark current and residual non-linearity of the CCD. We present and discuss the QE measurements performed on the CLASP cameras. We also discuss the high-vacuum system outfitted for testing of UV and EUV science cameras at MSFC.

  14. Description and Flight Test Results of the NASA F-8 Digital Fly-by-Wire Control System

    Science.gov (United States)

    1975-01-01

    A NASA program to develop digital fly-by-wire (DFBW) technology for aircraft applications is discussed. Phase I of the program demonstrated the feasibility of using a digital fly-by-wire system for aircraft control through developing and flight testing a single channel system, which used Apollo hardware, in an F-8C airplane. The objective of Phase II of the program is to establish a technology base for designing practical DFBW systems. It will involve developing and flight testing a triplex digital fly-by-wire system using state-of-the-art airborne computers, system hardware, software, and redundancy concepts. The papers included in this report describe the Phase I system and its development and present results from the flight program. Man-rated flight software and the effects of lightning on digital flight control systems are also discussed.

  15. 14 CFR 61.405 - What tests do I have to take to obtain a flight instructor certificate with a sport pilot rating?

    Science.gov (United States)

    2010-01-01

    ... flight instructor certificate with a sport pilot rating? 61.405 Section 61.405 Aeronautics and Space..., FLIGHT INSTRUCTORS, AND GROUND INSTRUCTORS Flight Instructors With a Sport Pilot Rating § 61.405 What tests do I have to take to obtain a flight instructor certificate with a sport pilot rating? To obtain a...

  16. Design and testing of a magnetorheological damper to control both vibration and shock loads for a vehicle crew seat

    Science.gov (United States)

    Becnel, Andrew; Hu, Wei; Hiemenz, Gregory J.; Wereley, Norman M.

    2010-04-01

    A magnetorheological shock absorber (MRSA) prototype is designed, fabricated and tested to integrate semiactive shock and vibration mitigation technology into the existing Expeditionary Fighting Vehicle (EFV) forward seating positions. Utilizing Bingham-Plastic (BP) constitutive fluid relationships and a steady state fluid flow model, the MR valve parameters are determined using magnetic circuit analysis, and subsequently validated via electromagnetic finite element analysis (FEA). Low speed (up to 0.9 m/s) simulations of normal vibration mode operation are conducted on the MRSA prototype using single frequency sinusoidal displacements by a servohydraulic testing machine. The high speed (up to 2.2 m/s) design procedure is verified by using a rail-guided drop test stand to impact a known payload mass onto the damper shaft. A refined hydromechanical model of the MRSA under both cyclic and impact loadings is developed and validated using the measured test data. This ratedependent, mechanisms-based model predicts the time response of the MRSA under both loading conditions. The hydromechanical analysis marks a significant improvement over previous linear models. Key design considerations for the MRSA to accommodate both vibration and shock spectra using a single MR device are presented.

  17. Optimization of the design of X-Calibur for a long-duration balloon flight and results from a one-day test flight

    Science.gov (United States)

    Kislat, Fabian; Abarr, Quin; Beheshtipour, Banafsheh; De Geronimo, Gianluigi; Dowkontt, Paul; Tang, Jason; Krawczynski, Henric

    2018-01-01

    X-ray polarimetry promises exciting insights into the physics of compact astrophysical objects by providing two observables: the polarization fraction and angle as function of energy. X-Calibur is a balloon-borne hard x-ray scattering polarimeter for the 15- to 60-keV energy range. After the successful test flight in September 2016, the instrument is now being prepared for a long-duration balloon (LDB) flight in December 2018 through January 2019. During the LDB flight, X-Calibur will make detailed measurements of the polarization of Vela X-1 and constrain the polarization of a sample of between 4 and 9 additional sources. We describe the upgraded polarimeter design, including the use of a beryllium scattering element, lower-noise front-end electronics, and an improved fully active CsI(Na) anticoincidence shield, which will significantly increase the instrument sensitivity. We present estimates of the improved polarimeter performance based on simulations and laboratory measurements. We present some of the results from the 2016 flight and show that we solved several problems, which led to a reduced sensitivity during the 2016 flight. We end with a description of the planned Vela X-1 observations, including a Swift/BAT-guided observation strategy.

  18. Preparation and Integration of ALHAT Precision Landing Technology for Morpheus Flight Testing

    Science.gov (United States)

    Carson, John M., III; Robertson, Edward A.; Pierrottet, Diego F.; Roback, Vincent E.; Trawny, Nikolas; Devolites, Jennifer L.; Hart, Jeremy J.; Estes, Jay N.; Gaddis, Gregory S.

    2014-01-01

    The Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) project has developed a suite of prototype sensors for enabling autonomous and safe precision land- ing of robotic or crewed vehicles on solid solar bodies under varying terrain lighting condi- tions. The sensors include a Lidar-based Hazard Detection System (HDS), a multipurpose Navigation Doppler Lidar (NDL), and a long-range Laser Altimeter (LAlt). Preparation for terrestrial ight testing of ALHAT onboard the Morpheus free- ying, rocket-propelled ight test vehicle has been in progress since 2012, with ight tests over a lunar-like ter- rain eld occurring in Spring 2014. Signi cant work e orts within both the ALHAT and Morpheus projects has been required in the preparation of the sensors, vehicle, and test facilities for interfacing, integrating and verifying overall system performance to ensure readiness for ight testing. The ALHAT sensors have undergone numerous stand-alone sensor tests, simulations, and calibrations, along with integrated-system tests in special- ized gantries, trucks, helicopters and xed-wing aircraft. A lunar-like terrain environment was constructed for ALHAT system testing during Morpheus ights, and vibration and thermal testing of the ALHAT sensors was performed based on Morpheus ights prior to ALHAT integration. High- delity simulations were implemented to gain insight into integrated ALHAT sensors and Morpheus GN&C system performance, and command and telemetry interfacing and functional testing was conducted once the ALHAT sensors and electronics were integrated onto Morpheus. This paper captures some of the details and lessons learned in the planning, preparation and integration of the individual ALHAT sen- sors, the vehicle, and the test environment that led up to the joint ight tests.

  19. Testing an emerging paradigm in migration ecology shows surprising differences in efficiency between flight modes.

    Directory of Open Access Journals (Sweden)

    Adam E Duerr

    Full Text Available To maximize fitness, flying animals should maximize flight speed while minimizing energetic expenditure. Soaring speeds of large-bodied birds are determined by flight routes and tradeoffs between minimizing time and energetic costs. Large raptors migrating in eastern North America predominantly glide between thermals that provide lift or soar along slopes or ridgelines using orographic lift (slope soaring. It is usually assumed that slope soaring is faster than thermal gliding because forward progress is constant compared to interrupted progress when birds pause to regain altitude in thermals. We tested this slope-soaring hypothesis using high-frequency GPS-GSM telemetry devices to track golden eagles during northbound migration. In contrast to expectations, flight speed was slower when slope soaring and eagles also were diverted from their migratory path, incurring possible energetic costs and reducing speed of progress towards a migratory endpoint. When gliding between thermals, eagles stayed on track and fast gliding speeds compensated for lack of progress during thermal soaring. When thermals were not available, eagles minimized migration time, not energy, by choosing energetically expensive slope soaring instead of waiting for thermals to develop. Sites suited to slope soaring include ridges preferred for wind-energy generation, thus avian risk of collision with wind turbines is associated with evolutionary trade-offs required to maximize fitness of time-minimizing migratory raptors.

  20. Testing an emerging paradigm in migration ecology shows surprising differences in efficiency between flight modes.

    Science.gov (United States)

    Duerr, Adam E; Miller, Tricia A; Lanzone, Michael; Brandes, Dave; Cooper, Jeff; O'Malley, Kieran; Maisonneuve, Charles; Tremblay, Junior; Katzner, Todd

    2012-01-01

    To maximize fitness, flying animals should maximize flight speed while minimizing energetic expenditure. Soaring speeds of large-bodied birds are determined by flight routes and tradeoffs between minimizing time and energetic costs. Large raptors migrating in eastern North America predominantly glide between thermals that provide lift or soar along slopes or ridgelines using orographic lift (slope soaring). It is usually assumed that slope soaring is faster than thermal gliding because forward progress is constant compared to interrupted progress when birds pause to regain altitude in thermals. We tested this slope-soaring hypothesis using high-frequency GPS-GSM telemetry devices to track golden eagles during northbound migration. In contrast to expectations, flight speed was slower when slope soaring and eagles also were diverted from their migratory path, incurring possible energetic costs and reducing speed of progress towards a migratory endpoint. When gliding between thermals, eagles stayed on track and fast gliding speeds compensated for lack of progress during thermal soaring. When thermals were not available, eagles minimized migration time, not energy, by choosing energetically expensive slope soaring instead of waiting for thermals to develop. Sites suited to slope soaring include ridges preferred for wind-energy generation, thus avian risk of collision with wind turbines is associated with evolutionary trade-offs required to maximize fitness of time-minimizing migratory raptors.

  1. Flight test of a head-worn display as an equivalent-HUD for terminal operations

    Science.gov (United States)

    Shelton, K. J.; Arthur, J. J.; Prinzel, L. J.; Nicholas, S. N.; Williams, S. P.; Bailey, R. E.

    2015-05-01

    Research, development, test, and evaluation of flight deck interface technologies is being conducted by NASA to proactively identify, develop, and mature tools, methods, and technologies for improving overall aircraft safety of new and legacy vehicles operating in the Next Generation Air Transportation System (NextGen). Under NASA's Aviation Safety Program, one specific area of research is the use of small Head-Worn Displays (HWDs) as a potential equivalent display to a Head-up Display (HUD). Title 14 of the US CFR 91.175 describes a possible operational credit which can be obtained with airplane equipage of a HUD or an "equivalent"' display combined with Enhanced Vision (EV). A successful HWD implementation may provide the same safety and operational benefits as current HUD-equipped aircraft but for significantly more aircraft in which HUD installation is neither practical nor possible. A flight test was conducted to evaluate if the HWD, coupled with a head-tracker, can provide an equivalent display to a HUD. Approach and taxi testing was performed on-board NASA's experimental King Air aircraft in various visual conditions. Preliminary quantitative results indicate the HWD tested provided equivalent HUD performance, however operational issues were uncovered. The HWD showed significant potential as all of the pilots liked the increased situation awareness attributable to the HWD's unique capability of unlimited field-of-regard.

  2. Flying Boresight for Advanced Testing and Calibration of Tracking Antennas and Flight Path Simulations

    Science.gov (United States)

    Hafner, D.

    2015-09-01

    The application of ground-based boresight sources for calibration and testing of tracking antennas usually entails various difficulties, mostly due to unwanted ground effects. To avoid this problem, DLR MORABA developed a small, lightweight, frequency-adjustable S-band boresight source, mounted on a small remote-controlled multirotor aircraft. Highly accurate GPS-supported, position and altitude control functions allow both, very steady positioning of the aircraft in mid-air, and precise waypoint-based, semi-autonomous flights. In contrast to fixed near-ground boresight sources this flying setup enables to avoid obstructions in the Fresnel zone between source and antenna. Further, it minimizes ground reflections and other multipath effects which can affect antenna calibration. In addition, the large operating range of a flying boresight simplifies measurements in the far field of the antenna and permits undisturbed antenna pattern tests. A unique application is the realistic simulation of sophisticated flight paths, including overhead tracking and demanding trajectories of fast objects such as sounding rockets. Likewise, dynamic tracking tests are feasible which provide crucial information about the antenna pedestal performance — particularly at high elevations — and reveal weaknesses in the autotrack control loop of tracking antenna systems. During acceptance tests of MORABA's new tracking antennas, a manned aircraft was never used, since the Flying Boresight surpassed all expectations regarding usability, efficiency, and precision. Hence, it became an integral part of MORABA's standard antenna setup and calibration procedures.

  3. Testing the time-of-flight model for flagellar length sensing.

    Science.gov (United States)

    Ishikawa, Hiroaki; Marshall, Wallace F

    2017-11-07

    Cilia and flagella are microtubule-based organelles that protrude from the surface of most cells, are important to the sensing of extracellular signals, and make a driving force for fluid flow. Maintenance of flagellar length requires an active transport process known as intraflagellar transport (IFT). Recent studies reveal that the amount of IFT injection negatively correlates with the length of flagella. These observations suggest that a length-dependent feedback regulates IFT. However, it is unknown how cells recognize the length of flagella and control IFT. Several theoretical models try to explain this feedback system. We focused on one of the models, the "time-of-flight" model, which measures the length of flagella on the basis of the travel time of IFT protein in the flagellar compartment. We tested the time-of-flight model using Chlamydomonas dynein mutant cells, which show slower retrograde transport speed. The amount of IFT injection in dynein mutant cells was higher than that in control cells. This observation does not support the prediction of the time-of-flight model and suggests that Chlamydomonas uses another length-control feedback system rather than that described by the time-of-flight model. © 2017 Ishikawa and Marshall. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  4. 76 FR 64229 - Function and Reliability Flight Testing for Turbine-Powered Airplanes Weighing 6,000 Pounds or Less

    Science.gov (United States)

    2011-10-18

    ... F & R flight testing regardless of the airplane's systems complexity or level of automation. After... than some transport category airplanes of the 1960s and earlier. The NPRM contains more of the...

  5. 75 FR 18134 - Function and Reliability Flight Testing for Turbine-Powered Airplanes Weighing 6,000 Pounds or Less

    Science.gov (United States)

    2010-04-09

    ... undergo F & R flight testing regardless of the airplane's systems complexity or level of automation. After... airplanes that weigh 6,000 pounds or less to be more complex and integrated than some transport category...

  6. Guidance, Navigation and Control (GN and C) Design Overview and Flight Test Results from NASA's Max Launch Abort System (MLAS)

    Science.gov (United States)

    Dennehy, Cornelius J.; Lanzi, Raymond J.; Ward, Philip R.

    2010-01-01

    The National Aeronautics and Space Administration Engineering and Safety Center designed, developed and flew the alternative Max Launch Abort System (MLAS) as risk mitigation for the baseline Orion spacecraft launch abort system already in development. The NESC was tasked with both formulating a conceptual objective system design of this alternative MLAS as well as demonstrating this concept with a simulated pad abort flight test. Less than 2 years after Project start the MLAS simulated pad abort flight test was successfully conducted from Wallops Island on July 8, 2009. The entire flight test duration was 88 seconds during which time multiple staging events were performed and nine separate critically timed parachute deployments occurred as scheduled. This paper provides an overview of the guidance navigation and control technical approaches employed on this rapid prototyping activity; describes the methodology used to design the MLAS flight test vehicle; and lessons that were learned during this rapid prototyping project are also summarized.

  7. Pilot Field Test: Use of a Compression Garment During a Stand Test After Long-Duration Space Flight

    Science.gov (United States)

    Laurie, S. S.; Stenger, M. B.; Phillips, T. R.; Lee, S. M. C.; Cerisano, J.; Kofman, I.; Reschke, M.

    2016-01-01

    Orthostatic intolerance (OI) is a concern for astronauts returning from long-duration space flight. One countermeasure that has been used to protect against OI after short-duration bed rest and space flight is the use of lower body and abdominal compression garments. However, since the end of the Space Shuttle era we have not been able to test crewmembers during the first 24 hours after landing on Earth. NASA's Pilot Field Test provided us the opportunity to test cardiovascular responses of crewmembers wearing the Russian Kentavr compression garment during a stand test at multiple time points throughout the first 24 hours after landing. HYPOTHESIS We hypothesized that the Kentavr compression garment would prevent an increase in heart rate (HR) >15 bpm during a 3.5-min stand test. METHODS: The Pilot Field Test was conducted up to 3 times during the first 24 hours after crewmembers returned to Earth: (1) either in a tent adjacent to the Soyuz landing site in Kazakhstan (approx.1 hr) or after transportation to the Karaganda airport (approx. 4 hr); (2) during a refueling stop in Scotland (approx.12 hr); and (3) upon return to NASA Johnson Space Center (JSC) (approx.24 hr). We measured HR and arterial pressure (finger photoplethysmography) for 2 min while the crewmember was prone and throughout 3.5 min of quiet standing. Eleven crewmembers consented to participate; however, 2 felt too ill to start the test and 1 stopped 30 sec into the stand portion of the test. Of the remaining 8 crewmembers, 2 did not wear the Russian Kentavr compression garment. Because of inclement weather at the landing site, 5 crewmembers were flown by helicopter to the Karaganda airport before initial testing and received intravenous saline before completing the stand test. One of these crewmembers wore only the portion of the Russian Kentavr compression garment that covered the lower leg and thus lacked thigh and abdominal compression. All crewmembers continued wearing the Russian Kentavr

  8. The Building Blocks for JWST I and T (Integrations and Test) to Operations - From Simulator to Flight Units

    Science.gov (United States)

    Fatig, Curtis; Ochs, William; Johns, Alan; Seaton, Bonita; Adams, Cynthia; Wasiak, Francis; Jones, Ronald; Jackson, Wallace

    2012-01-01

    The James Webb Space Telescope (JWST) Project has an extended integration and test (I&T) phase due to long procurement and development times of various components as well as recent launch delays. The JWST Ground Segment and Operations group has developed a roadmap of the various ground and flight elements and their use in the various JWST I&T test programs. The JWST Project s building block approach to the eventual operational systems, while not new, is complex and challenging; a large-scale mission like JWST involves international partners, many vendors across the United States, and competing needs for the same systems. One of the challenges is resource balancing so simulators and flight products for various elements congeal into integrated systems used for I&T and flight operations activities. This building block approach to an incremental buildup provides for early problem identification with simulators and exercises the flight operations systems, products, and interfaces during the JWST I&T test programs. The JWST Project has completed some early I&T with the simulators, engineering models and some components of the operational ground system. The JWST Project is testing the various flight units as they are delivered and will continue to do so for the entire flight and operational system. The JWST Project has already and will continue to reap the value of the building block approach on the road to launch and flight operations.

  9. Vibration monitoring of the primary piping system during the hot functional tests of the Muelheim-Kaerlich PWR

    International Nuclear Information System (INIS)

    Bauernfeind, V.; Bloem, T.; Pache, W.; Diederich, H.J.

    1992-01-01

    During the hot functional tests of the Muelheim-Kaerlich plant, which was the first plant of its type, vibration measurements were made on the reactor pressure vessel and its internal parts and on the primary piping system and the main coolant pumps. This paper contains the results of the measurements taken on the pipes and the pumps with an interpretation of these measurements based on an analytical model of the primary system. The main aim of the measurement programs is to confirm that the components, which are of new structural design, are adequately dimensioned for the operational vibration loads during the service life of the reactor. In addition, the vibrational modes of the hot lines, the steam generators and the pumps with the adjacent cold lines were determined. These values were compared with the analytically calculated resonance frequencies and eigenforms. A good correspondence was found. In the course of these comparisons, information about the modelling of the supporting structures and the efficiency of the damping elements during normal operation was obtained. The vibration of the main coolant pumps was also continuously monitored. The pump surveillance system for each pump includes two non-contacting displacement sensors for measuring the kinetic shaft orbit, as well as velocity sensors for recording the vibrational velocity of the pump motor housing. During the continuous monitoring, it was checked whether the signal amplitudes remained within the allowable limits. In addition the frequency content of the signals was determined periodically. In this way deviations could be detected immediately and be explained by means of subsequent correlation analysis. Thus amplitude changes resulting from resonance effects were identified. (orig.)

  10. Establishment of one-axis vibration test system for measurement of biodynamic response of human hand-arm system.

    Science.gov (United States)

    Shibata, Nobuyuki; Hosoya, Naoki; Maeda, Setsuo

    2008-12-01

    basis of the results obtained in this study, we conclude that this hand-arm vibration test system can be used to measure biodynamic response parameters of the human hand-arm system.

  11. Flight test of a spin parachute for use with a Super Arcas sounding rocket

    Science.gov (United States)

    Silbert, M. N.

    1975-01-01

    The development and flight testing of a specially configured 16.6 ft Disc Band Gap (DBG) Spin Parachute is discussed. The parachute is integrated with a modified Super Arcas launch vehicle. Total payload weight was 17.6 lbs including the Spin Parachute and a scientific payload, and lift-off weight was 100.3 lbs. The Super Arcas vehicle was despun from 18.4 cps. After payload separation at 244,170 ft the Spin Parachute and its payload attained a maximum spin rate of 2.4 cps. Total suspended weight of the Spin Parachute and its payload was 14.64 lbs.

  12. A measurement of Omega from the North American test flight of Boomerang

    International Nuclear Information System (INIS)

    Melchiorri, A.; Ade, P.A.R.; De Bernardis, P.; Bock, J.J.; Borrill, J.; Boscaleri, A.; Crill, B.P.; De Troia, G.; Farese, P.; Ferreira, P.G.; Ganga, K.; Gasperis, G. de; Giacometti, M.; Hristov, V.V.; Jaffe, A.H.; Lange, A.E.; Masi, S.; Mauskopf, P.D.; Miglio, L.; Netterfield, C.B.; Pascale, E.; Piacentini, F.; Romeo, G.; Ruhl, J.E.; Vittorio, N.

    1999-01-01

    We use the power spectrum of the Cosmic Microwave Background, measured during the North American test flight of the BOOMERANG experiment, to constrain the geometry of the universe. Within the class of Cold Dark Matter models, we find the overall fractional energy density of the universe, Omega, is constrained to be 0.85 < or = Omega < or = 1.25 at the 68 percent confidence level. Combined with the COBE measurement and the high redshift supernovae data we obtain new constraints on the fractional matter density and the cosmological constant

  13. A measurement of $\\Omega$ from the North American test flight of BOOMERANG

    CERN Document Server

    Melchiorri, A; De Bernardis, P; Bock, J J; Borrill, J; Boscaleri, A; Crill, B P; De Troia, G; Farese, P; Ferreira, P G; Ganga, K; De Gasperis, G; Giacometti, M; Hristov, V V; Jaffe, A H; Lange, A E; Masi, S; Mauskopf, P D; Miglio, L; Netterfield, C B; Pascale, E; Piacentini, F; Romeo, G

    2000-01-01

    We use the angular power spectrum of the Cosmic Microwave Background, measured during the North American test flight of the BOOMERANG experiment, to constrain the geometry of the universe. Within the class of Cold Dark Matter models, we find that the overall fractional energy density of the universe, Omega, is constrained to be 0.85 < Omega < 1.25 at the 68% confidence level. Combined with the COBE measurement and the high redshift supernovae data we obtain new constraints on the fractional matter density and the cosmological constant.

  14. Application of Computational Fluid Dynamics (CFD) in transonic wind-tunnel/flight-test correlation

    Science.gov (United States)

    Murman, E. M.

    1982-01-01

    The capability for calculating transonic flows for realistic configurations and conditions is discussed. Various phenomena which were modeled are shown to have the same order of magnitude on the influence of predicted results. It is concluded that CFD can make the following contributions to the task of correlating wind tunnel and flight test data: some effects of geometry differences and aeroelastic distortion can be predicted; tunnel wall effects can be assessed and corrected for; and the effects of model support systems and free stream nonuniformities can be modeled.

  15. Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGA.

    Science.gov (United States)

    Glebov, V Yu; Forrest, C; Knauer, J P; Pruyne, A; Romanofsky, M; Sangster, T C; Shoup, M J; Stoeckl, C; Caggiano, J A; Carman, M L; Clancy, T J; Hatarik, R; McNaney, J; Zaitseva, N P

    2012-10-01

    A new neutron time-of-flight (nTOF) detector with a bibenzyl crystal as a scintillator has been designed and manufactured for the National Ignition Facility (NIF). This detector will replace a nTOF20-Spec detector with an oxygenated xylene scintillator currently operational on the NIF to improve the areal-density measurements. In addition to areal density, the bibenzyl detector will measure the D-D and D-T neutron yield and the ion temperature of indirect- and direct-drive-implosion experiments. The design of the bibenzyl detector and results of tests on the OMEGA Laser System are presented.

  16. Test Operations Procedure (TOP) 05-2-543 Enhanced Flight Termination Receiver (EFTR) Range Certification Testing

    Science.gov (United States)

    2011-07-25

    35 5.10 Signal Strength Telemetry Output ( SSTO ) (Test Number 10) ............ 38 5.11 Operational...All command outputs and monitor outputs shall respond properly. TOP 05-2-543 25 July 2011 38 5.10 Signal Strength Telemetry Output ( SSTO ...Test Number 10). a. Purpose. This test verifies that the signal strength telemetry output ( SSTO ) voltage is monotonic and directly related to the

  17. UAS Integration in the NAS Project: Flight Test 3 Data Analysis of JADEM-Autoresolver Detect and Avoid System

    Science.gov (United States)

    Gong, Chester; Wu, Minghong G.; Santiago, Confesor

    2016-01-01

    The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS Integration in the NAS, aims to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The UAS Integration in the NAS Project conducted a flight test activity, referred to as Flight Test 3 (FT3), involving several Detect-and-Avoid (DAA) research prototype systems between June 15, 2015 and August 12, 2015 at the Armstrong Flight Research Center (AFRC). This report documents the flight testing and analysis results for the NASA Ames-developed JADEM-Autoresolver DAA system, referred to as 'Autoresolver' herein. Four flight test days (June 17, 18, 22, and July 22) were dedicated to Autoresolver testing. The objectives of this test were as follows: 1. Validate CPA prediction accuracy and detect-and-avoid (DAA, formerly known as self-separation) alerting logic in realistic flight conditions. 2. Validate DAA trajectory model including maneuvers. 3. Evaluate TCAS/DAA interoperability. 4. Inform final Minimum Operating Performance Standards (MOPS). Flight test scenarios were designed to collect data to directly address the objectives 1-3. Objective 4, inform final MOPS, was a general objective applicable to the UAS in the NAS project as a whole, of which flight test is a subset. This report presents analysis results completed in support of the UAS in the NAS project FT3 data review conducted on October 20, 2015. Due to time constraints and, to a lesser extent, TCAS data collection issues, objective 3 was not evaluated in this analysis.

  18. Operational Lessons Learned from the Ares I-X Flight Test

    Science.gov (United States)

    Davis, Stephan R.

    2010-01-01

    The Ares I-X flight test, launched in 2009, is the first test of the Ares I crew launch vehicle. This development flight test evaluated the flight dynamics, roll control, and separation events, but also provided early insights into logistical, stacking, launch, and recovery operations for Ares I. Operational lessons will be especially important for NASA as the agency makes the transition from the Space Shuttle to the Constellation Program, which is designed to be less labor-intensive. The mission team itself comprised only 700 individuals over the life of the project compared to the thousands involved in Shuttle and Apollo missions; while missions to and beyond low-Earth orbit obviously will require additional personnel, this lean approach will serve as a model for future Constellation missions. To prepare for Ares I-X, vehicle stacking and launch infrastructure had to be modified at Kennedy Space Center's Vehicle Assembly Building (VAB) as well as Launch Complex (LC) 39B. In the VAB, several platforms and other structures designed for the Shuttle s configuration had to be removed to accommodate the in-line, much taller Ares I-X. Vehicle preparation activities resulted in delays, but also in lessons learned for ground operations personnel, including hardware deliveries, cable routing, transferred work and custodial paperwork. Ares I-X also proved to be a resource challenge, as individuals and ground service equipment (GSE) supporting the mission also were required for Shuttle or Atlas V operations at LC 40/41 at Cape Canaveral Air Force Station. At LC 39B, several Shuttle-specific access arms were removed and others were added to accommodate the in-line Ares vehicle. Ground command, control, and communication (GC3) hardware was incorporated into the Mobile Launcher Platform (MLP). The lightning protection system at LC 39B was replaced by a trio of 600-foot-tall towers connected by a catenary wire to account for the much greater height of the vehicle. Like Shuttle

  19. Accelerated lifetime test of vibration isolator made of Metal Rubber material

    Science.gov (United States)

    Ao, Hongrui; Ma, Yong; Wang, Xianbiao; Chen, Jianye; Jiang, Hongyuan

    2017-01-01

    The Metal Rubber material (MR) is a kind of material with nonlinear damping characteristics for its application in the field of aerospace, petrochemical industry and so on. The study on the lifetime of MR material is impendent to its application in engineering. Based on the dynamic characteristic of MR, the accelerated lifetime experiments of vibration isolators made of MR working under random vibration load were conducted. The effects of structural parameters of MR components on the lifetime of isolators were studied and modelled with the fitting curves of degradation data. The lifetime prediction methods were proposed based on the models.

  20. A flight management algorithm and guidance for fuel-conservative descents in a time-based metered air traffic environment: Development and flight test results

    Science.gov (United States)

    Knox, C. E.

    1984-01-01

    A simple airborne flight management descent algorithm designed to define a flight profile subject to the constraints of using idle thrust, a clean airplane configuration (landing gear up, flaps zero, and speed brakes retracted), and fixed-time end conditions was developed and flight tested in the NASA TSRV B-737 research airplane. The research test flights, conducted in the Denver ARTCC automated time-based metering LFM/PD ATC environment, demonstrated that time guidance and control in the cockpit was acceptable to the pilots and ATC controllers and resulted in arrival of the airplane over the metering fix with standard deviations in airspeed error of 6.5 knots, in altitude error of 23.7 m (77.8 ft), and in arrival time accuracy of 12 sec. These accuracies indicated a good representation of airplane performance and wind modeling. Fuel savings will be obtained on a fleet-wide basis through a reduction of the time error dispersions at the metering fix and on a single-airplane basis by presenting the pilot with guidance for a fuel-efficient descent.

  1. Adaptive structures flight experiments

    Science.gov (United States)

    Martin, Maurice

    The topics are presented in viewgraph form and include the following: adaptive structures flight experiments; enhanced resolution using active vibration suppression; Advanced Controls Technology Experiment (ACTEX); ACTEX program status; ACTEX-2; ACTEX-2 program status; modular control patch; STRV-1b Cryocooler Vibration Suppression Experiment; STRV-1b program status; Precision Optical Bench Experiment (PROBE); Clementine Spacecraft Configuration; TECHSAT all-composite spacecraft; Inexpensive Structures and Materials Flight Experiment (INFLEX); and INFLEX program status.

  2. International Space Station Bacteria Filter Element Post-Flight Testing and Service Life Prediction

    Science.gov (United States)

    Perry, J. L.; von Jouanne, R. G.; Turner, E. H.

    2003-01-01

    The International Space Station uses high efficiency particulate air (HEPA) filters to remove particulate matter from the cabin atmosphere. Known as Bacteria Filter Elements (BFEs), there are 13 elements deployed on board the ISS's U.S. Segment. The pre-flight service life prediction of 1 year for the BFEs is based upon performance engineering analysis of data collected during developmental testing that used a synthetic dust challenge. While this challenge is considered reasonable and conservative from a design perspective, an understanding of the actual filter loading is required to best manage the critical ISS Program resources. Thus testing was conducted on BFEs returned from the ISS to refine the service life prediction. Results from this testing and implications to ISS resource management are discussed. Recommendations for realizing significant savings to the ISS Program are presented.

  3. Tests and Calibration of the NIF Neutron Time of Flight Detectors

    International Nuclear Information System (INIS)

    Ali, Z.A.; Glebov, V.Yu.; Cruz, M.; Duffy, T.; Stoeckl, C.; Roberts, S.; Sangster, T.C.; Tommasini, R.; Throop, A; Moran, M.; Dauffy, L.; Horsefield, C.

    2008-01-01

    The National Ignition Facility (NIF) Neutron Time of Flight (NTOF) diagnostic will measure neutron yield and ion temperature in all NIF campaigns in DD, DT, and THD (D = deuterium, T = tritium, H = hydrogen) implosions. The NIF NTOF diagnostic is designed to measure neutron yield from 10 9 to 2 x 10 19 . The NTOF consists of several detectors of varying sensitivity located on the NIF at about 5 m and 20 m from the target. Production, testing, and calibration of the NIF NTOF detectors have begun at the Laboratory for Laser Energetics (LLE). Operational tests of the NTOF detectors were performed on several facilities including the OMEGA laser at LLE and the Titan laser at Lawrence Livermore National Laboratory (LLNL). Neutron calibrations were carried out on the OMEGA laser. Results of the NTOF detectors tests and calibration will be presented

  4. Space Environment Testing of Photovoltaic Array Systems at NASA's Marshall Space Flight Center

    Science.gov (United States)

    Phillips, Brandon S.; Schneider, Todd A.; Vaughn, Jason A.; Wright, Kenneth H., Jr.

    2015-01-01

    To successfully operate a photovoltaic (PV) array system in space requires planning and testing to account for the effects of the space environment. It is critical to understand space environment interactions not only on the PV components, but also the array substrate materials, wiring harnesses, connectors, and protection circuitry (e.g. blocking diodes). Key elements of the space environment which must be accounted for in a PV system design include: Solar Photon Radiation, Charged Particle Radiation, Plasma, and Thermal Cycling. While solar photon radiation is central to generating power in PV systems, the complete spectrum includes short wavelength ultraviolet components, which photo-ionize materials, as well as long wavelength infrared which heat materials. High energy electron radiation has been demonstrated to significantly reduce the output power of III-V type PV cells; and proton radiation damages material surfaces - often impacting coverglasses and antireflective coatings. Plasma environments influence electrostatic charging of PV array materials, and must be understood to ensure that long duration arcs do not form and potentially destroy PV cells. Thermal cycling impacts all components on a PV array by inducing stresses due to thermal expansion and contraction. Given such demanding environments, and the complexity of structures and materials that form a PV array system, mission success can only be ensured through realistic testing in the laboratory. NASA's Marshall Space Flight Center has developed a broad space environment test capability to allow PV array designers and manufacturers to verify their system's integrity and avoid costly on-orbit failures. The Marshall Space Flight Center test capabilities are available to government, commercial, and university customers. Test solutions are tailored to meet the customer's needs, and can include performance assessments, such as flash testing in the case of PV cells.

  5. Flight test results for the Daedalus and Light Eagle human powered aircraft

    Science.gov (United States)

    Sullivan, R. Bryan; Zerweckh, Siegfried H.

    1988-01-01

    The results of the flight test program of the Daedalus and Light Eagle human powered aircraft in the winter of 1987/88 are given. The results from experiments exploring the Light Eagle's rigid body and structural dynamics are presented. The interactions of these dynamics with the autopilot design are investigated. Estimates of the power required to fly the Daedalus aircraft are detailed. The system of sensors, signal conditioning boards, and data acquisition equipment used to record the flight data is also described. In order to investigate the dynamics of the aircraft, flight test maneuvers were developed to yield maximum data quality from the point of view of estimating lateral and longitudinal stability derivatives. From this data, structural flexibility and unsteady aerodynamics have been modeled in an ad hoc manner and are used to augment the equations of motion with flexibility effects. Results of maneuvers that were flown are compared with the predictions from the flexibility model. To extend the ad hoc flexibility model, a fully flexible aeroelastic model has been developed. The model is unusual in the approximate equality of many structural natural frequencies and the importance of unsteady aerodynamic effects. the Gossamer Albatross. It is hypothesized that this inverse ground effect is caused by turbulence in the Earth's boundary layer. The diameters of the largest boundary layer eddies (which represent most of the turbulent kinetic energy) are proportional to altitude; thus, closer to the ground, the energy in the boundary layer becomes concentrated in eddies of smaller and smaller diameter. Eventually the eddies become sufficiently small (approximately 0.5 cm) that they trip the laminar boundary layer on the wing. As a result, a greater percentage of the wing area is covered with turbulent flow. Consequently the aircraft's drag and the pow er required both increase as the aircraft flies closer to the ground. The results of the flight test program are

  6. Development of a sine-dwell ground vibration test (GVT) system

    CSIR Research Space (South Africa)

    Van Zyl, Lourens H

    2006-02-27

    Full Text Available to ensure that it will be free from flutter within the intended operating envelope. Long-span bridges are also subject to flutter, and high-rise buildings can oscillate severely in high winds. Vibrations in industrial installations are also quite common...

  7. Dynamic analysis and vibration testing of CFRP drive-line system used in heavy-duty machine tool

    Science.gov (United States)

    Yang, Mo; Gui, Lin; Hu, Yefa; Ding, Guoping; Song, Chunsheng

    2018-03-01

    Low critical rotary speed and large vibration in the metal drive-line system of heavy-duty machine tool affect the machining precision seriously. Replacing metal drive-line with the CFRP drive-line can effectively solve this problem. Based on the composite laminated theory and the transfer matrix method (TMM), this paper puts forward a modified TMM to analyze dynamic characteristics of CFRP drive-line system. With this modified TMM, the CFRP drive-line of a heavy vertical miller is analyzed. And the finite element modal analysis model of the shafting is established. The results of the modified TMM and finite element analysis (FEA) show that the modified TMM can effectively predict the critical rotary speed of CFRP drive-line. And the critical rotary speed of CFRP drive-line is 20% higher than that of the original metal drive-line. Then, the vibration of the CFRP and the metal drive-line were tested. The test results show that application of the CFRP drive shaft in the drive-line can effectively reduce the vibration of the heavy-duty machine tool.

  8. Analysis of Droplet Size during the Ice Accumulation Phase Of Flight Testing

    Science.gov (United States)

    Miller, Eric James

    2004-01-01

    There are numerous hazards associated with air travel. One of the most serious dangers to the pilot and passengers safety is the result of flying into conditions which are conducive to the formation of ice on the surface of an aircraft. Being a pilot myself I am very aware of the dangers that Icing can pose and the effects it can have on an airplane. A couple of the missions of the Icing branch is to make flying safer with more research to increase our knowledge of how ice effects the aerodynamics of an airfoil, and to increase are knowledge of the weather for better forecasting. The Icing Branch uses three different tools to determine the aerodynamic affects that icing has on a wing. The Icing research tunnel is an efficient way to test various airfoils in a controlled setting. To make sure the data received from the wind tunnel is accurate the Icing branch conducts real flight tests with the DHC-6 Twin Otter. This makes sure that the methods used in the wind tunnel accurately model what happens on the actual aircraft. These two tools are also compared to the LEWICE code which is a program that models the ice shape that would be formed on an airfoil in the particular weather conditions that are input by the user. One benefit of LEWICE is that it is a lot cheaper to run than the wind tunnel or flight tests which make it a nice tool for engineers designing aircraft that don t have the money to spend on icing research. Using all three of these tools is a way to cross check the data received from one and check it against the other two. industries, but it is also looked at by weather analysts who are trying to improve forecasting methods. The best way to avoid the troubles of icing encounters is to not go into it in the first place. By looking over the flight data the analyst can determine which conditions will most likely lead to an icing encounter and then this information will aid forecasters when briefing the pilots on the weather conditions. am looking at the

  9. An on-road shock and vibration response test series utilizing worst case and statistical analysis techniques

    International Nuclear Information System (INIS)

    Cap, J.S.

    1997-01-01

    Defining the maximum expected shock and vibration responses for an on-road truck transportation environment is strongly dependent on the amount of response data that can be obtained. One common test scheme consists of measuring response data over a relatively short prescribed road course and then reviewing that data to obtain the maximum response levels. The more mathematically rigorous alternative is to collect an unbiased ensemble of response data during a long road trip. This paper compares data gathered both ways during a recent on-road certification test for a tractor trailer van being designed by Sandia

  10. ATON (Autonomous Terrain-based Optical Navigation) for exploration missions: recent flight test results

    Science.gov (United States)

    Theil, S.; Ammann, N.; Andert, F.; Franz, T.; Krüger, H.; Lehner, H.; Lingenauber, M.; Lüdtke, D.; Maass, B.; Paproth, C.; Wohlfeil, J.

    2018-03-01

    Since 2010 the German Aerospace Center is working on the project Autonomous Terrain-based Optical Navigation (ATON). Its objective is the development of technologies which allow autonomous navigation of spacecraft in orbit around and during landing on celestial bodies like the Moon, planets, asteroids and comets. The project developed different image processing techniques and optical navigation methods as well as sensor data fusion. The setup—which is applicable to many exploration missions—consists of an inertial measurement unit, a laser altimeter, a star tracker and one or multiple navigation cameras. In the past years, several milestones have been achieved. It started with the setup of a simulation environment including the detailed simulation of camera images. This was continued by hardware-in-the-loop tests in the Testbed for Robotic Optical Navigation (TRON) where images were generated by real cameras in a simulated downscaled lunar landing scene. Data were recorded in helicopter flight tests and post-processed in real-time to increase maturity of the algorithms and to optimize the software. Recently, two more milestones have been achieved. In late 2016, the whole navigation system setup was flying on an unmanned helicopter while processing all sensor information onboard in real time. For the latest milestone the navigation system was tested in closed-loop on the unmanned helicopter. For that purpose the ATON navigation system provided the navigation state for the guidance and control of the unmanned helicopter replacing the GPS-based standard navigation system. The paper will give an introduction to the ATON project and its concept. The methods and algorithms of ATON are briefly described. The flight test results of the latest two milestones are presented and discussed.

  11. TRISTAR I: Evaluation Methods for Testing Head-Up Display (HUD) Flight Symbology

    National Research Council Canada - National Science Library

    Newman, R

    1995-01-01

    A piloted head up display (HUD) flight symbology study (TRISTAR) measuring pilot task performance was conducted at the NASA Ames Research Center by the Tri-Service Flight Symbology Working Group (FSWO...

  12. Communication: Vibrational relaxation of CO(1Σ) in collision with Ar(1S) at temperatures relevant to the hypersonic flight regime.

    Science.gov (United States)

    Denis-Alpizar, Otoniel; Bemish, Raymond J; Meuwly, Markus

    2017-03-21

    Vibrational energy relaxation (VER) of diatomics following collisions with the surrounding medium is an important elementary process for modeling high-temperature gas flow. VER is characterized by two parameters: the vibrational relaxation time τ vib and the state relaxation rates. Here the vibrational relaxation of CO(ν=0←ν=1) in Ar is considered for validating a computational approach to determine the vibrational relaxation time parameter (pτ vib ) using an accurate, fully dimensional potential energy surface. For lower temperatures, comparison with experimental data shows very good agreement whereas at higher temperatures (up to 25 000 K), comparisons with an empirically modified model due to Park confirm its validity for CO in Ar. Additionally, the calculations provide insight into the importance of Δν>1 transitions that are ignored in typical applications of the Landau-Teller framework.

  13. Probing Aircraft Flight Test Hazard Mitigation for the Alternative Fuel Effects on Contrails & Cruise Emissions (ACCESS) Research Team

    Science.gov (United States)

    Kelly, Michael J.

    2013-01-01

    The Alternative Fuel Effects on Contrails & Cruise Emissions (ACCESS) Project Integration Manager requested in July 2012 that the NASA Engineering and Safety Center (NESC) form a team to independently assess aircraft structural failure hazards associated with the ACCESS experiment and to identify potential flight test hazard mitigations to ensure flight safety. The ACCESS Project Integration Manager subsequently requested that the assessment scope be focused predominantly on structural failure risks to the aircraft empennage raft empennage.

  14. Vibration monitoring of the primary piping systems during the hot functional tests of the Mulheim-Karlich PWR

    International Nuclear Information System (INIS)

    Bauernfeind, V.; Bloem, T.; Pache, W.; Diederich, H.J.

    1989-01-01

    During the hot functional tests of the Muelheim--Kaerlich first-of-a-kind plant, vibration measurements were made on the reactor pressure vessel and its' internals and on the primary piping system and main coolant pumps. This paper contains results of the measurements taken on the pipes and the pumps with an interpretation of these measurements based on an analytical model of the primary system. The main aim of the measurement program is to confirm that the components, which are of new design, are adequately dimensioned for the operational vibration loads during the service life of the reactor. In addition, the vibrational modes of the hot lines, the steam generators and the pumps with the adjacent cold lines were determined. These values were compared with the analytically calculated resonance frequencies and eigenforms. Good agreement was found. In the course of these comparisons, information on the modelling of the supporting structures and the efficiency of the damping elements during normal operation was obtained

  15. Control and Non-Payload Communications Generation 1 Prototype Radio Flight Test Report

    Science.gov (United States)

    Shalkhauser, Kurt A.; Young, Daniel P.; Bretmersky, Steven C.; Ishac, Joseph A.; Walker, Steven H.; Griner, James H.; Kachmar, Brian A.

    2014-01-01

    regularity of flight. Only recently has radiofrequency (RF) spectrum been allocated by the International Telecommunications Union specifically for commercial UA C2, LOS communication (L-Band: 960 to 1164 MHz, and C-Band: 5030 to 5091 MHz). The safe and efficient integration of UA into the NAS requires the use of protected RF spectrum allocations and a new data communications system that is both secure and scalable to accommodate the potential growth of these new aircraft. Data communications for UA-referred to as control and non-payload communications (CNPC)-will be used to exchange information between a UA and a ground station (GS) to ensure safe, reliable, and effective UA flight operation. The focus of this effort is on validating and allocating new RF spectrum and data link communications to enable civil UA integration into the NAS. Through a cost-sharing cooperative agreement with Rockwell Collins, Inc., the NASA Glenn Research Center is exploring and performing the necessary development steps to realize a prototype UA CNPC system. These activities include investigating signal waveforms and access techniques, developing representative CNPC radio hardware, and executing relevant testing and validation activities. There is no intent to manufacture the CNPC end product, rather the goals are to study, demonstrate, and validate a typical CNPC system that will allow safe and efficient communications within the L-Band and C-Band spectrum allocations. The system is addressing initial "seed" requirements from RTCA, Inc., Special Committee 203 (SC-203) and is on a path to Federal Aviation Administration certification. This report provides results from the flight testing campaign of the Rockwell Collins Generation 1 prototype radio, referred hereafter as the "radio." The radio sets operate within the 960- to 977-MHz frequency band with both air and ground radios using identical hardware. Flight tests involved one aircraft and one GS. Results include discussion of aircraft flight

  16. Structural Health Monitoring Using Wireless Technologies: An Ambient Vibration Test on the Adolphe Bridge, Luxembourg City

    Directory of Open Access Journals (Sweden)

    Adrien Oth

    2012-01-01

    Full Text Available Major threats to bridges primarily consist of the aging of the structural elements, earthquake-induced shaking and standing waves generated by windstorms. The necessity of information on the state of health of structures in real-time, allowing for timely warnings in the case of damaging events, requires structural health monitoring (SHM systems that allow the risks of these threats to be mitigated. Here we present the results of a short-duration experiment carried out with low-cost wireless instruments for monitoring the vibration characteristics and dynamic properties of a strategic civil infrastructure, the Adolphe Bridge in Luxembourg City. The Adolphe Bridge is a masonry arch construction dating from 1903 and will undergo major renovation works in the upcoming years. Our experiment shows that a network of these wireless sensing units is well suited to monitor the vibration characteristics of such a historical arch bridge and hence represents a low-cost and efficient solution for SHM.

  17. Optimal Control Allocation with Load Sensor Feedback for Active Load Suppression, Flight-Test Performance

    Science.gov (United States)

    Miller, Christopher J.; Goodrick, Dan

    2017-01-01

    The problem of control command and maneuver induced structural loads is an important aspect of any control system design. The aircraft structure and the control architecture must be designed to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to utilize high structural margins, restrict control surface commands to a limited set of analyzed combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage. An optimal control technique has been explored and shown to achieve desirable vehicle control performance while limiting sensed structural loads to specified values. This technique has been implemented and flown on the National Aeronautics and Space Administration Full-scale Advanced Systems Testbed aircraft. The flight tests illustrate that the approach achieves the desired performance and show promising potential benefits. The flights also uncovered some important issues that will need to be addressed for production application.

  18. Small UAV Automatic Ground Collision Avoidance System Design Considerations and Flight Test Results

    Science.gov (United States)

    Sorokowski, Paul; Skoog, Mark; Burrows, Scott; Thomas, SaraKatie

    2015-01-01

    The National Aeronautics and Space Administration (NASA) Armstrong Flight Research Center Small Unmanned Aerial Vehicle (SUAV) Automatic Ground Collision Avoidance System (Auto GCAS) project demonstrated several important collision avoidance technologies. First, the SUAV Auto GCAS design included capabilities to take advantage of terrain avoidance maneuvers flying turns to either side as well as straight over terrain. Second, the design also included innovative digital elevation model (DEM) scanning methods. The combination of multi-trajectory options and new scanning methods demonstrated the ability to reduce the nuisance potential of the SUAV while maintaining robust terrain avoidance. Third, the Auto GCAS algorithms were hosted on the processor inside a smartphone, providing a lightweight hardware configuration for use in either the ground control station or on board the test aircraft. Finally, compression of DEM data for the entire Earth and successful hosting of that data on the smartphone was demonstrated. The SUAV Auto GCAS project demonstrated that together these methods and technologies have the potential to dramatically reduce the number of controlled flight into terrain mishaps across a wide range of aviation platforms with similar capabilities including UAVs, general aviation aircraft, helicopters, and model aircraft.

  19. Trajectory Reconstruction and Uncertainty Analysis Using Mars Science Laboratory Pre-Flight Scale Model Aeroballistic Testing

    Science.gov (United States)

    Lugo, Rafael A.; Tolson, Robert H.; Schoenenberger, Mark

    2013-01-01

    As part of the Mars Science Laboratory (MSL) trajectory reconstruction effort at NASA Langley Research Center, free-flight aeroballistic experiments of instrumented MSL scale models was conducted at Aberdeen Proving Ground in Maryland. The models carried an inertial measurement unit (IMU) and a flush air data system (FADS) similar to the MSL Entry Atmospheric Data System (MEADS) that provided data types similar to those from the MSL entry. Multiple sources of redundant data were available, including tracking radar and on-board magnetometers. These experimental data enabled the testing and validation of the various tools and methodologies that will be used for MSL trajectory reconstruction. The aerodynamic parameters Mach number, angle of attack, and sideslip angle were estimated using minimum variance with a priori to combine the pressure data and pre-flight computational fluid dynamics (CFD) data. Both linear and non-linear pressure model terms were also estimated for each pressure transducer as a measure of the errors introduced by CFD and transducer calibration. Parameter uncertainties were estimated using a "consider parameters" approach.

  20. Assessing Arboreal Adaptations of Bird Antecedents: Testing the Ecological Setting of the Origin of the Avian Flight Stroke

    Science.gov (United States)

    Dececchi, T. Alexander; Larsson, Hans C. E.

    2011-01-01

    The origin of avian flight is a classic macroevolutionary transition with research spanning over a century. Two competing models explaining this locomotory transition have been discussed for decades: ground up versus trees down. Although it is impossible to directly test either of these theories, it is possible to test one of the requirements for the trees-down model, that of an arboreal paravian. We test for arboreality in non-avian theropods and early birds with comparisons to extant avian, mammalian, and reptilian scansors and climbers using a comprehensive set of morphological characters. Non-avian theropods, including the small, feathered deinonychosaurs, and Archaeopteryx, consistently and significantly cluster with fully terrestrial extant mammals and ground-based birds, such as ratites. Basal birds, more advanced than Archaeopteryx, cluster with extant perching ground-foraging birds. Evolutionary trends immediately prior to the origin of birds indicate skeletal adaptations opposite that expected for arboreal climbers. Results reject an arboreal capacity for the avian stem lineage, thus lending no support for the trees-down model. Support for a fully terrestrial ecology and origin of the avian flight stroke has broad implications for the origin of powered flight for this clade. A terrestrial origin for the avian flight stroke challenges the need for an intermediate gliding phase, presents the best resolved series of the evolution of vertebrate powered flight, and may differ fundamentally from the origin of bat and pterosaur flight, whose antecedents have been postulated to have been arboreal and gliding. PMID:21857918

  1. Assessing arboreal adaptations of bird antecedents: testing the ecological setting of the origin of the avian flight stroke.

    Directory of Open Access Journals (Sweden)

    T Alexander Dececchi

    Full Text Available The origin of avian flight is a classic macroevolutionary transition with research spanning over a century. Two competing models explaining this locomotory transition have been discussed for decades: ground up versus trees down. Although it is impossible to directly test either of these theories, it is possible to test one of the requirements for the trees-down model, that of an arboreal paravian. We test for arboreality in non-avian theropods and early birds with comparisons to extant avian, mammalian, and reptilian scansors and climbers using a comprehensive set of morphological characters. Non-avian theropods, including the small, feathered deinonychosaurs, and Archaeopteryx, consistently and significantly cluster with fully terrestrial extant mammals and ground-based birds, such as ratites. Basal birds, more advanced than Archaeopteryx, cluster with extant perching ground-foraging birds. Evolutionary trends immediately prior to the origin of birds indicate skeletal adaptations opposite that expected for arboreal climbers. Results reject an arboreal capacity for the avian stem lineage, thus lending no support for the trees-down model. Support for a fully terrestrial ecology and origin of the avian flight stroke has broad implications for the origin of powered flight for this clade. A terrestrial origin for the avian flight stroke challenges the need for an intermediate gliding phase, presents the best resolved series of the evolution of vertebrate powered flight, and may differ fundamentally from the origin of bat and pterosaur flight, whose antecedents have been postulated to have been arboreal and gliding.

  2. Immunotoxicity and genotoxicity testing for in-flight experiments under microgravity

    Science.gov (United States)

    Hansen, Peter-Diedrich; Hansen, Peter-Diedrich; Unruh, Eckehardt

    Life Sciences as Related to Space (F) Influence of Spaceflight Environment on Biological Systems (F44) Immunotoxicity and genotoxicity testing for In-flight experiments under microgravity Sensing approaches for ecosystem and human health Author: Peter D. Hansen Technische Universit¨t Berlin, Faculty VI - Planen, Bauen, Umwelt, a Institute for Ecological Research and Technology, Department for Ecotoxicology, Berlin, Germany Peter-diedrich.hansen@tu-berlin.de Eckehardt Unruh Technische Universit¨t Berlin, Faculty VI - Planen, Bauen, Umwelt, Institute a for Ecological Research and Technology, Department for Ecotoxicology, Berlin, Germany An immune response by mussel hemocytes is the selective reaction to particles which are identified as foreign by its immune system shown by phagocytosis. Phagocytotic activity is based on the chemotaxis and adhesion, ingestion and phagosome formation. The attachment at the surface of the hemocytes and consequently the uptake of the particles or bacteria can be directly quantified in the format of a fluorescent assay. Another relevant endpoint of phagocytosis is oxidative burst measured by luminescence. Phagocytosis-related production of ROS will be stimulated with opsonised zymosan. The hemocytes will be stored frozen at -80oC and reconstituted in-flight for the experiment. The assay system of the TRIPLELUX-B Experiment has been performed with a well-defined quantification and evaluation of the immune function phagocytosis. The indicator cells are the hemocytes of blue mussels (Mytilus edulis). The signals of the immuno cellular responses are translated into luminescence as a rapid optical reporter system. The results expected will determine whether the observed responses are caused by microgravity and/or radiation (change in permeability, endpoints in genotoxicity: DNA unwinding). The samples for genotoxicity will be processed after returning to earth. The immune system of invertebrates has not been studied so far in space. The

  3. Summary of the First High-Altitude, Supersonic Flight Dynamics Test for the Low-Density Supersonic Decelerator Project

    Science.gov (United States)

    Clark, Ian G.; Adler, Mark; Manning, Rob

    2015-01-01

    NASA's Low-Density Supersonic Decelerator Project is developing and testing the next generation of supersonic aerodynamic decelerators for planetary entry. A key element of that development is the testing of full-scale articles in conditions relevant to their intended use, primarily the tenuous Mars atmosphere. To achieve this testing, the LDSD project developed a test architecture similar to that used by the Viking Project in the early 1970's for the qualification of their supersonic parachute. A large, helium filled scientific balloon is used to hoist a 4.7 m blunt body test vehicle to an altitude of approximately 32 kilometers. The test vehicle is released from the balloon, spun up for gyroscopic stability, and accelerated to over four times the speed of sound and an altitude of 50 kilometers using a large solid rocket motor. Once at those conditions, the vehicle is despun and the test period begins. The first flight of this architecture occurred on June 28th of 2014. Though primarily a shake out flight of the new test system, the flight was also able to achieve an early test of two of the LDSD technologies, a large 6 m diameter Supersonic Inflatable Aerodynamic Decelerator (SIAD) and a large, 30.5 m nominal diameter supersonic parachute. This paper summarizes this first flight.

  4. Flight test operations using an F-106B research airplane modified with a wing leading-edge vortex flap

    Science.gov (United States)

    Dicarlo, Daniel J.; Brown, Philip W.; Hallissy, James B.

    1992-01-01

    Flight tests of an F-106B aircraft equipped with a leading-edge vortex flap, which represented the culmination of a research effort to examine the effectiveness of the flap, were conducted at the NASA Langley Research Center. The purpose of the flight tests was to establish a data base on the use of a wing leading-edge vortex flap as a means to validate the design and analysis methods associated with the development of such a vortical flow-control concept. The overall experiment included: refinements of the design codes for vortex flaps; numerous wind tunnel entries to aid in verifying design codes and determining basic aerodynamic characteristics; design and fabrication of the flaps, structural modifications to the wing tip and leading edges of the test aircraft; development and installation of an aircraft research instrumentation system, including wing and flap surface pressure measurements and selected structural loads measurements; ground-based simulation to assess flying qualities; and finally, flight testing. This paper reviews the operational aspects associated with the flight experiment, which includes a description of modifications to the research airplane, the overall flight test procedures, and problems encountered. Selected research results are also presented to illustrate the accomplishments of the research effort.

  5. Comparison of analysis and flight test data for a drone aircraft with active flutter suppression

    Science.gov (United States)

    Newsom, J. R.; Pototzky, A. S.

    1981-01-01

    A drone aircraft equipped with an active flutter suppression system is considered with emphasis on the comparison of modal dampings and frequencies as a function of Mach number. Results are presented for both symmetric and antisymmetric motion with flutter suppression off. Only symmetric results are given for flutter suppression on. Frequency response functions of the vehicle are presented from both flight test data and analysis. The analysis correlation is improved by using an empirical aerodynamic correction factor which is proportional to the ratio of experimental to analytical steady-state lift curve slope. The mathematical models are included and existing analytical techniques are described as well as an alternative analytical technique for obtaining closed-loop results.

  6. A method for calibration and test of the time-of-flight detectors for DELPHI

    International Nuclear Information System (INIS)

    Benlloch, J.M.; Castillo, M.V.; Ferrer, A.; Fuster, J.; Higon, E.; Lozano, J.; Salt, J.; Sanchez, E.; Sanchis, E.; Cuevas, J.

    1990-01-01

    We describe a method for calibration and test of large-area TOF counters using cosmic radiation. We applied the method to the time-of-flight system of the DELPHI detector at the LEP e + e - storage ring, made of scintillation (NE110) counters (20x350 cm 2 ). The photomultipliers used (EMI 9902KB) reach an average gain of 5x10 8 at 1700 V and the time resolution achieved is 1.2 ns. Using this method we measured the counter efficiencies as a function of the position; we obtained 135 cm for the effective attenuation length and 40 photoelectrons for a minimum-ionizing particle crossing the center of the counter. (orig.)

  7. Testing of Full Scale Flight Qualified Kevlar Composite Overwrapped Pressure Vessels

    Science.gov (United States)

    Greene, Nathanael; Saulsberry, Regor; Yoder, Tommy; Forsyth, Brad; Thesken, John; Phoenix, Leigh

    2007-01-01

    Many decades ago NASA identified a need for low-mass pressure vessels for carrying various fluids aboard rockets, spacecraft, and satellites. A pressure vessel design known as the composite overwrapped pressure vessel (COPV) was identified to provide a weight savings over traditional single-material pressure vessels typically made of metal and this technology has been in use for space flight applications since the 1970's. A typical vessel design consisted of a thin liner material, typically a metal, overwrapped with a continuous fiber yarn impregnated with epoxy. Most designs were such that the overwrapped fiber would carry a majority of load at normal operating pressures. The weight advantage for a COPV versus a traditional singlematerial pressure vessel contributed to widespread use of COPVs by NASA, the military, and industry. This technology is currently used for personal breathing supply storage, fuel storage for auto and mass transport vehicles and for various space flight and aircraft applications. The NASA Engineering and Safety Center (NESC) was recently asked to review the operation of Kevlar 2 and carbon COPVs to ensure they are safely operated on NASA space flight vehicles. A request was made to evaluate the life remaining on the Kevlar COPVs used on the Space Shuttle for helium and nitrogen storage. This paper provides a review of Kevlar COPV testing relevant to the NESC assessment. Also discussed are some key findings, observations, and recommendations that may be applicable to the COPV user community. Questions raised during the investigations have revealed the need for testing to better understand the stress rupture life and age life of COPVs. The focus of this paper is to describe burst testing of Kevlar COPVs that has been completed as a part of an the effort to evaluate the effects of ageing and shelf life on full scale COPVs. The test articles evaluated in this discussion had a diameter of 22 inches for S/N 014 and 40 inches for S/N 011. The

  8. Identification of dynamic characteristics by field vibration test in Tsurumi Tsubasa bridge; Tsurumi Tsubasakyo no shindo jikken ni yoru doteki tokusei no dotei

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, H. [Saitama University, Saitama (Japan). Faculty of Engineering; Takano, H.; Ogasawara, M.; Shimosato, T. [Metropolitan Expressway Public Corp., Tokyo (Japan); Kato, M.; Okada, J. [NKK Corp., Tokyo (Japan)

    1996-07-21

    Field vibration test of the Tsurumi Tsubasa Bridge, a long span cable stayed bridge, has been conducted. Focusing on its dynamic characteristics, an identification method from test results and its validity were investigated. The natural frequency identified using mode circle and resonance curve from steady vibration test agreed with that identified by the peak method from free damping test. Accordingly, there was no difference due to identification methods, and both methods provided appropriate accuracy. The natural vibration mode obtained from the steady vibration test agreed with that obtained by the eigenvalue analysis. The dispersion of experimental values, which indicates the adaptation to mode circle method, became a scale indicating reliability of identified values. When the damping obtained by the half power method for the microtremors test is compared with that identified from the steady vibration test and free damping test, it is required to compare them at lower amplitude level region, considering that the amplitude level of microtremors test is very low. For the dynamic characteristics of the Tsurumi Tsubasa Bridge, it was found that it has lower natural frequency and higher modal damping compared with other cable stayed bridges with similar scale of span. 18 refs., 13 figs., 4 tabs.

  9. Probabilistic seismic safety assessment of a CANDU 6 nuclear power plant including ambient vibration tests: Case study

    Energy Technology Data Exchange (ETDEWEB)

    Nour, Ali [Hydro Québec, Montréal, Québec H2L4P5 (Canada); École Polytechnique de Montréal, Montréal, Québec H3C3A7 (Canada); Cherfaoui, Abdelhalim; Gocevski, Vladimir [Hydro Québec, Montréal, Québec H2L4P5 (Canada); Léger, Pierre [École Polytechnique de Montréal, Montréal, Québec H3C3A7 (Canada)

    2016-08-01

    Highlights: • In this case study, the seismic PSA methodology adopted for a CANDU 6 is presented. • Ambient vibrations testing to calibrate a 3D FEM and to reduce uncertainties is performed. • Procedure for the development of FRS for the RB considering wave incoherency effect is proposed. • Seismic fragility analysis for the RB is presented. - Abstract: Following the 2011 Fukushima Daiichi nuclear accident in Japan there is a worldwide interest in reducing uncertainties in seismic safety assessment of existing nuclear power plant (NPP). Within the scope of a Canadian refurbishment project of a CANDU 6 (NPP) put in service in 1983, structures and equipment must sustain a new seismic demand characterised by the uniform hazard spectrum (UHS) obtained from a site specific study defined for a return period of 1/10,000 years. This UHS exhibits larger spectral ordinates in the high-frequency range than those used in design. To reduce modeling uncertainties as part of a seismic probabilistic safety assessment (PSA), Hydro-Québec developed a procedure using ambient vibrations testing to calibrate a detailed 3D finite element model (FEM) of the containment and reactor building (RB). This calibrated FE model is then used for generating floor response spectra (FRS) based on ground motion time histories compatible with the UHS. Seismic fragility analyses of the reactor building (RB) and structural components are also performed in the context of a case study. Because the RB is founded on a large circular raft, it is possible to consider the effect of the seismic wave incoherency to filter out the high-frequency content, mainly above 10 Hz, using the incoherency transfer function (ITF) method. This allows reducing significantly the non-necessary conservatism in resulting FRS, an important issue for an existing NPP. The proposed case study, and related methodology using ambient vibration testing, is particularly useful to engineers involved in seismic re-evaluation of

  10. Development and flight test of metal-lined CFRP cryogenic tank for reusable rocket

    Science.gov (United States)

    Higuchi, Ken; Takeuchi, Shinsuke; Sato, Eiichi; Naruo, Yoshihiro; Inatani, Yoshifumi; Namiki, Fumiharu; Tanaka, Kohtaro; Watabe, Yoko

    2005-07-01

    A cryogenic tank made of carbon fiber reinforced plastic (CFRP) shell with aluminum thin liner has been designed as a liquid hydrogen (LH2) tank for an ISAS reusable launch vehicle, and the function of it has been proven by repeated flights onboard the test vehicle called reusable vehicle testing (RVT) in October 2003. The liquid hydrogen tank has to be a pressure vessel, because the fuel of the engine of the test vehicle is supplied by fuel pressure. The pressure vessel of a combination of the outer shell of CFRP for strength element at a cryogenic temperature and the inner liner of aluminum for gas barrier has shown excellent weight merit for this purpose. Interfaces such as tank outline shape, bulk capacity, maximum expected operating pressure (MEOP), thermal insulation, pipe arrangement, and measurement of data are also designed to be ready onboard. This research has many aims, not only development of reusable cryogenic composite tank but also the demonstration of repeated operation including thermal cycle and stress cycle, familiarization with test techniques of operation of cryogenic composite tanks, and the accumulation of data for future design of tanks, vehicle structures, safety evaluation, and total operation systems.

  11. UAS Integration in the NAS Project: Integrated Test and Evaluation (IT&E) Flight Test 3. Revision E

    Science.gov (United States)

    Marston, Michael

    2015-01-01

    The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration into the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability, Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including the integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project will conduct a series of Human-in-the-Loop and Flight Test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity and complexity of the previous tests and

  12. Flight Testing of the Space Launch System (SLS) Adaptive Augmenting Control (AAC) Algorithm on an F/A-18

    Science.gov (United States)

    Dennehy, Cornelius J.; VanZwieten, Tannen S.; Hanson, Curtis E.; Wall, John H.; Miller, Chris J.; Gilligan, Eric T.; Orr, Jeb S.

    2014-01-01

    The Marshall Space Flight Center (MSFC) Flight Mechanics and Analysis Division developed an adaptive augmenting control (AAC) algorithm for launch vehicles that improves robustness and performance on an as-needed basis by adapting a classical control algorithm to unexpected environments or variations in vehicle dynamics. This was baselined as part of the Space Launch System (SLS) flight control system. The NASA Engineering and Safety Center (NESC) was asked to partner with the SLS Program and the Space Technology Mission Directorate (STMD) Game Changing Development Program (GCDP) to flight test the AAC algorithm on a manned aircraft that can achieve a high level of dynamic similarity to a launch vehicle and raise the technology readiness of the algorithm early in the program. This document reports the outcome of the NESC assessment.

  13. Development of an Antimicrobial Susceptibility Testing Method Suitable for Performing During Space Flight

    Science.gov (United States)

    Jorgensen, James H.; Skweres, Joyce A.; Mishra S. K.; McElmeel, M. Letticia; Maher, Louise A.; Mulder, Ross; Lancaster, Michael V.; Pierson, Duane L.

    1997-01-01

    Very little is known regarding the affects of the microgravity environment of space flight upon the action of antimicrobial agents on bacterial pathogens. This study was undertaken to develop a simple method for conducting antibacterial susceptibility tests during a Space Shuttle mission. Specially prepared susceptibility test research cards (bioMerieux Vitek, Hazelwood, MO) were designed to include 6-11 serial two-fold dilutions of 14 antimicrobial agents, including penicillins, cephalosporins, a Beta-lactamase inhibitor, vancomycin, erythromycin, tetracycline, gentamicin, ciprofloxacin, and trimethoprim/sulfamethoxazole. Minimal inhibitory concentrations (MICS) of the drugs were determined by visual reading of color endpoints in the Vitek research cards made possible by incorporation of a colorimetric growth indicator (alamarBlue(Trademark), Accumed International, Westlake, OH). This study has demonstrated reproducible susceptibility results when testing isolates of Staphylococcus aurezis, Group A Streptococcus, Enterococcusfaecalis, Escherichia coli (beta-lactamase positive and negative strains), Klebsiella pneumoniae, Enterobacter cloacae, and Pseudomoiias aeruginosa. In some instances, the MICs were comparable to those determined using a standard broth microdilution method, while in some cases the unique test media and format yielded slightly different values, that were themselves reproducible. The proposed in-flight experiment will include inoculation of the Vitek cards on the ground prior to launch of the Space Shuttle, storage of inoculated cards at refrigeration temperature aboard the Space Shuttle until experiment initiation, then incubation of the cards for 18-48 h prior to visual interpretation of MICs by the mission's astronauts. Ground-based studies have shown reproducible MICs following storage of inoculated cards for 7 days at 4-8 C to accommodate the mission's time schedule and the astronauts' activities. For comparison, ground-based control

  14. Flight Test Comparison of Different Adaptive Augmentations for Fault Tolerant Control Laws for a Modified F-15 Aircraft

    Science.gov (United States)

    Burken, John J.; Hanson, Curtis E.; Lee, James A.; Kaneshige, John T.

    2009-01-01

    This report describes the improvements and enhancements to a neural network based approach for directly adapting to aerodynamic changes resulting from damage or failures. This research is a follow-on effort to flight tests performed on the NASA F-15 aircraft as part of the Intelligent Flight Control System research effort. Previous flight test results demonstrated the potential for performance improvement under destabilizing damage conditions. Little or no improvement was provided under simulated control surface failures, however, and the adaptive system was prone to pilot-induced oscillations. An improved controller was designed to reduce the occurrence of pilot-induced oscillations and increase robustness to failures in general. This report presents an analysis of the neural networks used in the previous flight test, the improved adaptive controller, and the baseline case with no adaptation. Flight test results demonstrate significant improvement in performance by using the new adaptive controller compared with the previous adaptive system and the baseline system for control surface failures.

  15. Flow-induced vibration test of an advanced water reactor model. Pt. 1. Turbulence-induced forcing function

    International Nuclear Information System (INIS)

    Au-Yang, M.K.; Brenneman, B.; Raj, D.

    1995-01-01

    A 1:9 scale model of a proposed advanced water reactor was tested for flow-induced vibration. The main objectives of this test were: (1) to derive an empirical equation for the turbulence forcing function which can be applied to the full-sized prototype; (2) to study the effect of viscosity on the turbulence; (3) to verify the ''superposition'' assumption widely used in dynamic analysis of weakly coupled fluid-shell systems; and (4) to measure the shell responses to verify methods and computer programs used in the flow-induced vibration analysis of the prototype. This paper describes objectives (1), (2), and (3); objective (4) will be discussed in a companion paper.The turbulence-induced fluctuating pressure was measured at 49 locations over the surface of a thick-walled, non-responsive scale model of the reactor vessel/core support cylinders. An empirical equation relating the fluctuating pressure, the frequency, and the distance from the inlet nozzle center line was derived to fit the test data. This equation involves only non-dimensional, fluid mechanical parameters that are postulated to represent the full-sized, geometrically similar prototype. While this postulate cannot be verified until similar measurements are taken on the full-sized unit, a similar approach using a 1:6 scale model of a commercial pressurized water reactor was verified in the mid-1970s by field measurements on the full-sized reactor. (orig.)

  16. Ground testing and flight demonstration of charge management of insulated test masses using UV-LED electron photoemission

    Science.gov (United States)

    Saraf, Shailendhar; Buchman, Sasha; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; Suwaidan, Badr Al; AlRashed, Abdullah; Al-Nassban, Badr; Alaqeel, Faisal; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; Alfauwaz, Abdulrahman; Al-Majed, Mohammed; DeBra, Daniel; Byer, Robert

    2016-12-01

    The UV-LED mission demonstrates the precise control of the potential of electrically isolated test masses. Test mass charge control is essential for the operation of space accelerometers and drag-free sensors which are at the core of geodesy, aeronomy and precision navigation missions as well as gravitational wave experiments and observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV-LED mission and prior ground testing demonstrates that AlGaN UVLEDs operating at 255 nm are superior to Hg lamps because of their smaller size, lower power draw, higher dynamic range, and higher control authority. We show laboratory data demonstrating the effectiveness and survivability of the UV-LED devices and performance of the charge management system. We also show flight data from a small satellite experiment that was one of the payloads on KACST’s SaudiSat-4 mission that demonstrates ‘AC charge control’ (UV-LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its housing. The result of the mission brings the UV-LED device Technology Readiness Level (TRL) to TRL-9 and the charge management system to TRL-7. We demonstrate the ability to control the test mass potential on an 89 mm diameter spherical test mass over a 20 mm gap in a drag-free system configuration, with potential measured using an ultra-high impedance contact probe. Finally, the key electrical and optical characteristics of the UV-LEDs showed less than 7.5% change in performance after 12 months in orbit.

  17. Ground testing and flight demonstration of charge management of insulated test masses using UV-LED electron photoemission

    International Nuclear Information System (INIS)

    Saraf, Shailendhar; Buchman, Sasha; Balakrishnan, Karthik; Lui, Chin Yang; Alfauwaz, Abdulrahman; DeBra, Daniel; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; Suwaidan, Badr Al; AlRashed, Abdullah; Al-Nassban, Badr; Alaqeel, Faisal; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; Al-Majed, Mohammed

    2016-01-01

    The UV-LED mission demonstrates the precise control of the potential of electrically isolated test masses. Test mass charge control is essential for the operation of space accelerometers and drag-free sensors which are at the core of geodesy, aeronomy and precision navigation missions as well as gravitational wave experiments and observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV-LED mission and prior ground testing demonstrates that AlGaN UVLEDs operating at 255 nm are superior to Hg lamps because of their smaller size, lower power draw, higher dynamic range, and higher control authority. We show laboratory data demonstrating the effectiveness and survivability of the UV-LED devices and performance of the charge management system. We also show flight data from a small satellite experiment that was one of the payloads on KACST’s SaudiSat-4 mission that demonstrates ‘AC charge control’ (UV-LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its housing. The result of the mission brings the UV-LED device Technology Readiness Level (TRL) to TRL-9 and the charge management system to TRL-7. We demonstrate the ability to control the test mass potential on an 89 mm diameter spherical test mass over a 20 mm gap in a drag-free system configuration, with potential measured using an ultra-high impedance contact probe. Finally, the key electrical and optical characteristics of the UV-LEDs showed less than 7.5% change in performance after 12 months in orbit. (paper)

  18. Random vibration tests of the anticoincidence system of the PAMELA satellite experiment

    CERN Document Server

    Pearce, M; Lundin, M; Lundqvist, J M

    2002-01-01

    PAMELA is a general purpose cosmic ray satellite experiment which will be launched early in 2003. An anticoincidence system surrounds the PAMELA silicon tracker to reject particles not clearly entering the acceptance of the experiment. The engineering model of the PAMELA anticounter system uses plastic scintillator which is read out by Hamamatsu R5900U photomultipliers. The anticounters have been subjected to the random vibration spectrum expected during the launch of PAMELA. The integrated amplitude experienced by the photomultipliers was O(20) g RMS. No degradation to the photomultiplier operation or mechanical assembly was observed.

  19. COBALT: Development of a Platform to Flight Test Lander GN&C Technologies on Suborbital Rockets

    Science.gov (United States)

    Carson, John M., III; Seubert, Carl R.; Amzajerdian, Farzin; Bergh, Chuck; Kourchians, Ara; Restrepo, Carolina I.; Villapando, Carlos Y.; O'Neal, Travis V.; Robertson, Edward A.; Pierrottet, Diego; hide

    2017-01-01

    The NASA COBALT Project (CoOperative Blending of Autonomous Landing Technologies) is developing and integrating new precision-landing Guidance, Navigation and Control (GN&C) technologies, along with developing a terrestrial fight-test platform for Technology Readiness Level (TRL) maturation. The current technologies include a third- generation Navigation Doppler Lidar (NDL) sensor for ultra-precise velocity and line- of-site (LOS) range measurements, and the Lander Vision System (LVS) that provides passive-optical Terrain Relative Navigation (TRN) estimates of map-relative position. The COBALT platform is self contained and includes the NDL and LVS sensors, blending filter, a custom compute element, power unit, and communication system. The platform incorporates a structural frame that has been designed to integrate with the payload frame onboard the new Masten Xodiac vertical take-o, vertical landing (VTVL) terrestrial rocket vehicle. Ground integration and testing is underway, and terrestrial fight testing onboard Xodiac is planned for 2017 with two flight campaigns: one open-loop and one closed-loop.

  20. Five years of testing using the simi-automated ultrasonic time of flight diffraction system

    International Nuclear Information System (INIS)

    Webber, S.A.

    2002-01-01

    This paper provides a brief description of the Time of Flight Diffraction (TOFD) test system and also describes a couple of case histories where the system has been successfully applied. The T.O.F.D. system has been contrasted with the conventional manual ultrasonic technique. Whilst the T.O.F.D. system has proven potential, and is without doubt a valuable tool that will continue to gain market share in the inspection industry, conventional manual ultrasonics still has its part to play and will survive for some time to come. One of the outstanding issues facing the T.O.F.D. systems is the question of acceptance testing which is still the predominant convention specified in most standards. Training for a T.O.F.D. system technician is particularly important and the author suggests there are more traps for the unwary than with the conventional manual ultrasonic systems. The overall judgement of the T.O.F.D. system is that it is a most welcome and powerful tool in the hands of the right operator and will do much to boost the prominence of Non-Destructive Testing

  1. Seismic analysis methods for LMFBR core and verification with mock-up vibration tests

    International Nuclear Information System (INIS)

    Sasaki, Y.; Kobayashi, T.; Fujimoto, S.

    1988-01-01

    This paper deals with the vibration behaviors of a cluster of core elements with the hexagonal cross section in a barrel under the dynamic excitation due to seismic events. When a strong earthquake excitation is applied to the core support, the cluster of core elements displace to a geometrical limit determined by restraint rings in the barrel, and collisions could occur between adjacent elements as a result of their relative motion. For these reasons, seismic analysis on LMFBR core elements is a complicated non-linear vibration problem, which includes collisions and fluid interactions. In an actual core design, it is hard to include hundreds of elements in the numerical calculations. In order to study the seismic behaviors of core elements, experiments with single row 29 elements (17 core fuel assemblies, 4 radial blanket assemblies, and 8 neutron shield assemblies) simulated all elements in MONJU core central row, and experiments with 7 cluster rows of 37 core fuel assemblies in the core center were performed in a fluid filled tank, using a large-sized shaking table. Moreover, the numerical analyses of these experiments were performed for the validation of simplified and detailed analytical methods. 4 refs, 18 figs

  2. New technological development of passive and active vibration control: analysis and test

    Science.gov (United States)

    Matsuzaki, Yuji; Ikeda, Tadashige; Boller, Christian

    2005-04-01

    We present a brief summary of new technical developments of passive and active vibration controls which we have performed for the last several years partly as an international collaborative R&D project on Smart Materials and Structural Systems sponsored by the Japanese Ministry of Economy, Trade and Industry. In connection with the passive damping control, shape memory alloys (SMAs) were used as damping elements. To examine the effect of damping enhancement, beams with SMA films bonded onto them or SMA wires embedded into them were made, and free damped oscillations were measured. The damping coefficient increased by more than 100% compared with the beams without SMAs. Thermodynamic behaviors of an SMA wire and film were also investigated experimentally and numerically. In active vibration control, a new concept of smart material systems was proposed. That is a partially magnetized alloy, which is stiff and strong enough as a structural element and responds sufficiently quickly as an actuator due to an electromagnetic force. A simplified experiment and numerical simulation were performed and the results showed the feasibility of the proposed smart material system using the electromagnetic force.

  3. Analysis of the forced vibration test of the Hualien large scale soil-structure interaction model using a flexible volume substructuring method

    International Nuclear Information System (INIS)

    Tang, H.T.; Nakamura, N.

    1995-01-01

    A 1/4-scale cylindrical reactor containment model was constructed in Hualien, Taiwan for foil-structure interaction (SSI) effect evaluation and SSI analysis procedure verification. Forced vibration tests were executed before backfill (FVT-1) and after backfill (FVT-2) to characterize soil-structure system characteristics under low excitations. A number of organizations participated in the pre-test blind prediction and post-test correlation analyses of the forced vibration test using various industry familiar methods. In the current study, correlation analyses were performed using a three-dimensional flexible volume substructuring method. The results are reported and soil property sensitivities are evaluated in the paper. (J.P.N.)

  4. Follow on Research for Multi-Utility Technology Test Bed Aircraft at NASA Dryden Flight Research Center (FY13 Progress Report)

    Science.gov (United States)

    Pak, Chan-Gi

    2013-01-01

    Modern aircraft employ a significant fraction of their weight in composite materials to reduce weight and improve performance. Aircraft aeroservoelastic models are typically characterized by significant levels of model parameter uncertainty due to the composite manufacturing process. Small modeling errors in the finite element model will eventually induce errors in the structural flexibility and mass, thus propagating into unpredictable errors in the unsteady aerodynamics and the control law design. One of the primary objectives of Multi Utility Technology Test-bed (MUTT) aircraft is the flight demonstration of active flutter suppression, and therefore in this study, the identification of the primary and secondary modes for the structural model tuning based on the flutter analysis of MUTT aircraft. The ground vibration test-validated structural dynamic finite element model of the MUTT aircraft is created in this study. The structural dynamic finite element model of MUTT aircraft is improved using the in-house Multi-disciplinary Design, Analysis, and Optimization tool. In this study, two different weight configurations of MUTT aircraft have been improved simultaneously in a single model tuning procedure.

  5. Manned/Unmanned Common Architecture Program (MCAP) net centric flight tests

    Science.gov (United States)

    Johnson, Dale

    2009-04-01

    Properly architected avionics systems can reduce the costs of periodic functional improvements, maintenance, and obsolescence. With this in mind, the U.S. Army Aviation Applied Technology Directorate (AATD) initiated the Manned/Unmanned Common Architecture Program (MCAP) in 2003 to develop an affordable, high-performance embedded mission processing architecture for potential application to multiple aviation platforms. MCAP analyzed Army helicopter and unmanned air vehicle (UAV) missions, identified supporting subsystems, surveyed advanced hardware and software technologies, and defined computational infrastructure technical requirements. The project selected a set of modular open systems standards and market-driven commercial-off-theshelf (COTS) electronics and software, and, developed experimental mission processors, network architectures, and software infrastructures supporting the integration of new capabilities, interoperability, and life cycle cost reductions. MCAP integrated the new mission processing architecture into an AH-64D Apache Longbow and participated in Future Combat Systems (FCS) network-centric operations field experiments in 2006 and 2007 at White Sands Missile Range (WSMR), New Mexico and at the Nevada Test and Training Range (NTTR) in 2008. The MCAP Apache also participated in PM C4ISR On-the-Move (OTM) Capstone Experiments 2007 (E07) and 2008 (E08) at Ft. Dix, NJ and conducted Mesa, Arizona local area flight tests in December 2005, February 2006, and June 2008.

  6. Test rig with active damping control for the simultaneous evaluation of vibration control and energy harvesting via piezoelectric transducers

    OpenAIRE

    Perfetto, Sara; Rohlfing, Jens; Infante, Francesco; Mayer, Dirk; Herold, Sven

    2016-01-01

    Piezoelectric transducers can be used to harvest electrical energy from structural vibrations in order to power continuously operating condition monitoring systems local to where they operate. However, excessive vibrations can compromise the safe operation of mechanical systems. Therefore, absorbers are commonly used to control vibrations. With an integrated device, the mechanical energy that otherwise would be dissipated can be converted via piezoelectric transducers. Vibration absorbers are...

  7. Gearbox vibration diagnostic analyzer

    Science.gov (United States)

    1992-01-01

    This report describes the Gearbox Vibration Diagnostic Analyzer installed in the NASA Lewis Research Center's 500 HP Helicopter Transmission Test Stand to monitor gearbox testing. The vibration of the gearbox is analyzed using diagnostic algorithms to calculate a parameter indicating damaged components.

  8. Measurement of a Peak in the Cosmic Microwave Background Power Spectrum from the North American test flight of BOOMERANG

    CERN Document Server

    Mauskopf, P D; De Bernardis, P; Bock, J J; Borrill, J; Boscaleri, A; Crill, B P; De Gasperis, G; De Troia, G; Farese, P; Ferreira, P G; Ganga, K; Giacometti, M; Hanany, S; Hristov, V V; Iacoangeli, A; Jaffe, A H; Lange, A E; Lee, A T; Masi, S; Melchiorri, A; Melchiorri, F; Miglio, L; Montroy, T; Netterfield, C B; Pascale, E; Piacentini, F; Richards, P L; Romeo, G; Ruhl, J E; Scannapieco, E S; Scaramuzzi, F; Stompor, R; Vittorio, N

    2000-01-01

    We describe a measurement of the angular power spectrum of anisotropies in the Cosmic Microwave Background (CMB) from 0.3 degrees to ~10 degrees from the North American test flight of the BOOMERANG experiment. BOOMERANG is a balloon-borne telescope with a bolometric receiver designed to map CMB anisotropies on a Long Duration Balloon flight. During a 6-hour test flight of a prototype system in 1997, we mapped > 200 square degrees at high galactic latitudes in two bands centered at 90 and 150 GHz with a resolution of 26 and 16.6 arcmin FWHM respectively. Analysis of the maps gives a power spectrum with a peak at angular scales of ~1 degree with an amplitude ~70 uK.

  9. Measurement of a peak in the cosmic microwave background power spectrum from the North American test flight of Boomerang

    International Nuclear Information System (INIS)

    Mauskopf, P.D.; Ade, P.A.R.; Bock, J.J.; Borrill, J.; Boscaleri, A.; Crill, B.P.; Bernardis, P. de; DeGasperis, G.; De Troia, G.; Farese, P.; Ferreira, P.G.; Ganga, K.; Giacometti, M.; Hanany, S.; Hristov, V.V.; Iacoangeli, A.; Jaffe, A.H.; Lange, A.E.; Lee, A.T.; Masi, S.; Melchiorri, A.; Melchiorri, F.; Miglio, L.; Montroy, T.; Netterfield, C.B.; Pascale, E.; Piacentini, F.; Richards, P.L.; Romeo, G.; Ruhl, J.E.; Scannapieco, E.; Scaramuzzi, F.; Stompor, R.; Vittorio, N.

    1999-01-01

    We describe a measurement of the angular power spectrum of anisotrophies in the Cosmic Microwave Background (CMB) from 0.2 deg to approx. 10 deg. from the test flight of the BOOMERANG experiment. BOOMERANG is a balloon-borne telescope with a bolometric receiver designed to map CMB anisotrophies on a Long Duration Balloon flight. During a 6-hour test flight of a prototype system in 1997, we mapped > 200 square degrees at high galactic latitudes in two bands centered at 90 and 150 GHz with a resolution of 26 and 16.6 arcmin FWHM respectively. Analysis of the maps gives a power spectrum with a peak at angular scales of approx. 1 deg. with an amplitude of approx. 70-muKcmb

  10. Hollow Fiber Flight Prototype Spacesuit Water Membrane Evaporator Design and Testing

    Science.gov (United States)

    Bue, Grant; Vogel, Matt; Makinen, Janice; Tsioulos, Gus

    2010-01-01

    The spacesuit water membrane evaporator (SWME) is being developed to perform thermal control for advanced spacesuits and to take advantage of recent advances in micropore membrane technology. This results in a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. The Membrana Celgard X50-215 microporous hollow-fiber (HoFi) membrane was selected after recent extensive testing as the most suitable candidate among commercial alternatives for continued SWME prototype development. The current design was based on a previous design that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape. This was developed into a full-scale prototype consisting of 14,300 tube bundled into 30 stacks, each of which is formed into a chevron shape and separated by spacers and organized into three sectors of 10 nested stacks. The new design replaced metal components with plastic ones, and has a custom built flight like backpressure valve mounted on the side of the SWME housing to reduce backpressure when fully open. The spacers that provided separation of the chevron fiber stacks were eliminated. Vacuum chamber testing showed improved heat rejection as a function of inlet water temperature and water vapor backpressure compared with the previous design. Other tests pushed the limits of tolerance to freezing and showed suitability to reject heat in a Mars pressure environment with and without a sweep gas. Tolerance to contamination by constituents expected to be found in potable water produced by distillation processes was tested in a conventional way by allowing constituents to accumulate in the coolant as evaporation occurs. For this purpose, the SWME cartridge has endured an equivalent of 30 EVAs exposure and demonstrated minimal performance decline.

  11. Hollow Fiber Space Water Membrane Evaporator Flight Prototype Design and Testing

    Science.gov (United States)

    Bue, Grant C.; Makinen, Janice; Vogel, Mtthew; Honas, Matt; Dillon, Paul; Colunga, Aaron; Truong, Lily; Porwitz, Darwin; Tsioulos, Gus

    2011-01-01

    The spacesuit water membrane evaporator (SWME) is being developed to perform thermal control for advanced spacesuits and to take advantage of recent advances in micropore membrane technology. This results in a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. The current design was based on a previous design that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape. This was developed into a full-scale prototype consisting of 14,300 tube bundled into 30 stacks, each of which is formed into a chevron shape and separated by spacers and organized into three sectors of 10 nested stacks. The new design replaced metal components with plastic ones, eliminated the spacers, and has a custom built flight like backpressure valve mounted on the side of the SWME housing to reduce backpressure when fully open. A number of tests were performed in order to improve the strength of the polyurethane header that holds the fibers in place while the system is pressurized. Vacuum chamber testing showed similar heat rejection as a function of inlet water temperature and water vapor backpressure was similar to the previous design. Other tests pushed the limits of tolerance to freezing and showed suitability to reject heat in a Mars pressure environment with and without a sweep gas. Tolerance to contamination by constituents expected to be found in potable water produced by distillation processes was tested in a conventional way by allowing constituents to accumulate in the coolant as evaporation occurs. For this purpose, the SWME cartridge has endured an equivalent of 30 EVAs exposure and demonstrated acceptable performance decline.

  12. Validation test of advanced technology for IPV nickel-hydrogen flight cells: Update

    Science.gov (United States)

    Smithrick, John J.; Hall, Stephen W.

    1992-01-01

    Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts with the intention of improving cycle life and performance. One advancement was to use 26 percent potassium hydroxide (KOH) electrolyte to improve cycle life. Another advancement was to modify the state-of-the-art cell design to eliminate identified failure modes. The modified design is referred to as the advanced design. A breakthrough in the low-earth-orbit (LEO) cycle life of IPV nickel-hydrogen cells has been previously reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3,500 cycles for cells containing 31 percent KOH. The boiler plate test results are in the process of being validated using flight hardware and real time LEO testing at the Naval Weapons Support Center (NWSC), Crane, Indiana under a NASA Lewis Contract. An advanced 125 Ah IPV nickel-hydrogen cell was designed. The primary function of the advanced cell is to store and deliver energy for long-term, LEO spacecraft missions. The new features of this design are: (1) use of 26 percent rather than 31 percent KOH electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are: extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of nickel electrode expansion. The advanced cell design is in the process of being validated using real time LEO cycle life testing of NWSC, Crane, Indiana. An update of validation test results confirming this technology is presented.

  13. Active vibration control based on piezoelectric smart composite

    International Nuclear Information System (INIS)

    Gao, Le; Lu, Qingqing; Fei, Fan; Leng, Jinsong; Liu, Liwu; Liu, Yanju

    2013-01-01

    An aircraft’s vertical fin may experience dramatic buffet loads in high angle of attack flight conditions, and these buffet loads would cause huge vibration and dynamic stress on the vertical fin structure. To reduce the dynamic vibration of the vertical fin structure, macro fiber composite (MFC) actuators were used in this paper. The drive moment equations and sensing voltage equations of the MFC actuators were developed. Finite element analysis models based on three kinds of models of simplified vertical fin structures with surface-bonded MFC actuators were established in ABAQUS. The equivalent damping ratio of the structure was employed in finite element analysis, in order to measure the effectiveness of vibration control. Further, an open-loop test for the active vibration control system of the vertical fin with MFC actuators was designed and developed. The experimental results validated the effectiveness of the MFC actuators as well as the developed methodology. (paper)

  14. Results from an Interval Management (IM) Flight Test and Its Potential Benefit to Air Traffic Management Operations

    Science.gov (United States)

    Baxley, Brian; Swieringa, Kurt; Berckefeldt, Rick; Boyle, Dan

    2017-01-01

    NASA's first Air Traffic Management Technology Demonstration (ATD-1) subproject successfully completed a 19-day flight test of an Interval Management (IM) avionics prototype. The prototype was built based on IM standards, integrated into two test aircraft, and then flown in real-world conditions to determine if the goals of improving aircraft efficiency and airport throughput during high-density arrival operations could be met. The ATD-1 concept of operation integrates advanced arrival scheduling, controller decision support tools, and the IM avionics to enable multiple time-based arrival streams into a high-density terminal airspace. IM contributes by calculating airspeeds that enable an aircraft to achieve a spacing interval behind the preceding aircraft. The IM avionics uses its data (route of flight, position, etc.) and Automatic Dependent Surveillance-Broadcast (ADS-B) state data from the Target aircraft to calculate this airspeed. The flight test demonstrated that the IM avionics prototype met the spacing accuracy design goal for three of the four IM operation types tested. The primary issue requiring attention for future IM work is the high rate of IM speed commands and speed reversals. In total, during this flight test, the IM avionics prototype showed significant promise in contributing to the goals of improving aircraft efficiency and airport throughput.

  15. Vibrational excitation of methane by positron impact: Computed quantum dynamics and sensitivity tests

    International Nuclear Information System (INIS)

    Nishimura, Tamio; Gianturco, Franco A.

    2002-01-01

    We report the quantum dynamical close-coupling equations relevant for vibrationally inelastic processes in low-energy collisions between a beam of positrons and the CH 4 molecule in the gas phase. The interaction potential is described in detail and we report also our numerical technique for solving the scattering equations. The cross sections are obtained for the excitations of all the modes of the title molecule and are compared both with simpler computational approximations and with the recent experiments for the two distinct energy regions that correspond to the combined symmetric and antisymmetric stretching modes and to twisting and scissoring modes, respectively. Our calculations reproduce well the shape and the values of the experimental findings and give useful insights into the microscopic dynamics for molecular excitation processes activated by low-energy positron scattering

  16. Critical test of vibrational dephasing theories in solids using spontaneous Raman scattering in isotopically mixed crystals

    International Nuclear Information System (INIS)

    Marks, S.; Cornelius, P.A.; Harris, C.B.

    1980-01-01

    A series of experiments have been conducted in order to evaluate the relative importance of several recent theories of vibrational dephasing in solids. The theories are discussed briefly, and are used to interpret the temperature dependence of the C--H and C--D stretch bands in the spontaneous Raman spectra of h 14 - and d 14 -1,2,4,5-tetramethyl benzene (durene). The infrared spectra of these same molecules are also reported in the region of the combination bands involving C--H (or C--D) stretches and low-frequency modes. The results support the applicability of the model of Harris et al., [C. B. Harris, R. M. Shelby and P. A. Cornelius, Phys. Rev. Lett. 38, 1415 (1977); Chem Phys. Lett. 57, 8 (1978); R. M. Shelby, C. B. Harris, and P. A. Cornelius, J. Chem. Phys. 70, 34 (1979)], based on energy exchange in anharmonically coupled low-frequency modes. This theory is then used, in connection with Raman spectra obtained in isotopically mixed samples of durene, to elucidate the vibrational dynamics underlying the dephasing. It is found that the results are consistent with the hypothesis that some low-frequency modes in this molecule are significantly delocalized or ''excitonic'' in character, and that this delocalization may be studied by means of Raman spectroscopy on the low-frequency modes themselves, as well as by exchange analysis of the coupled high-frequency modes. These conclusions represent a generalization and extension of the previously published exchange model [R. M. Shelby, C. B. Harris, and P. A. Cornelius, J. Chem Phys. 70, 34 (1979)

  17. Flight Testing of the Forward Osmosis Bag for Water Recovery on STS-135

    Science.gov (United States)

    Roberts, Michael S.; Soler, Monica; Mortenson, Todd; McCoy, LaShelle; Woodward, Spencer; Levine, Howard G.

    2011-01-01

    The Forward Osmosis Bag (FOB) is a personal water purification device for recovery of potable liquid from almost any non-potable water source. The FOB experiment was flown as a sortie mission on STS-135/ULF7 using flight-certified materials and a design based on the X-Pack(TradeMark) from Hydration Technology Innovations (Albany, OR). The primary objective was to validate the technology for use under microgravity conditions. The FOB utilizes a difference in solute concentration across a selectively permeable membrane to draw water molecules from the non-potable water while rejecting most chemical and all microbial contaminants contained within. Six FOB devices were tested on STS-135 for their ability to produce a potable liquid permeate from a feed solution containing 500 mL potassium chloride (15 g/L) amended with 0.1% methyl blue dye (w:v) tracer against an osmotic gradient created by addition of 60 mL of concentrate containing the osmolytes fructose and glucose, and 0.01% sodium fluorescein (w:v) tracer. Three FOB devices were physically mixed by hand for 2 minutes by a crewmember after loading to augment membrane wetting for comparison with three unmixed FOB devices. Hydraulic flux rate and rejection of salt and dye in microgravity were determined from a 60-mL sample collected by the crew on orbit after 6 hours. Post-flight analysis of samples collected on orbit demonstrated that the Forward Osmosis Bag achieved expected design specifications in microgravity. The hydraulic flux rate of water across the membrane was reduced approximately 50% in microgravity relative to ground controls that generated an average of 50 mL per hour using the same water and osmolyte solutions. The membrane rejected both potassium and chloride at >92% and methyl blue dye at >99.9%. Physical mixing of the FOB during water recovery did not have any significant effect on either flux rate or rejection of solutes from the water solution. The absence of buoyancy-driven convection in

  18. Flight Test Techniques. Proceedings of the Flight Mechanics Panel Symposium Held in Lisbon, Portugal on 2-5 April 1984

    Science.gov (United States)

    1984-07-01

    E103 3000 200 270090 1800 Fig. 7: Antenna Radiation Pattern Aircraft: D028. Type of Antenna: Monopole Frequency: 1.5 6Nz, Bank Angle: 0±Z Deg. Ref...Pattern: - - - Monopole Mr 70 250 F 4g. 8: S.uae1tpcl S0OA0r a) Test Emitter: Frequency Range UHF -18 GHz Antenna Parabolic Dish Wln Horn Feeds Transmitter...essais d’extinction et rallumages moteur, de flottement, etc.. Un effort sp~cial a 6t consacr6, Ai Istres, A Ia mice en place de moyens et dispositifs

  19. Analysis of Within-Test Variability of Non-Destructive Test Methods to Evaluate Compressive Strength of Normal Vibrated and Self-Compacting Concretes

    Science.gov (United States)

    Nepomuceno, Miguel C. S.; Lopes, Sérgio M. R.

    2017-10-01

    Non-destructive tests (NDT) have been used in the last decades for the assessment of in-situ quality and integrity of concrete elements. An important step in the application of NDT methods concerns to the interpretation and validation of the test results. In general, interpretation of NDT results should involve three distinct phases leading to the development of conclusions: processing of collected data, analysis of within-test variability and quantitative evaluation of property under investigation. The analysis of within-test variability can provide valuable information, since this can be compared with that of within-test variability associated with the NDT method in use, either to provide a measure of the quality control or to detect the presence of abnormal circumstances during the in-situ application. This paper reports the analysis of the experimental results of within-test variability of NDT obtained for normal vibrated concrete and self-compacting concrete. The NDT reported includes the surface hardness test, ultrasonic pulse velocity test, penetration resistance test, pull-off test, pull-out test and maturity test. The obtained results are discussed and conclusions are presented.

  20. Handling Qualities Flight Testing of the Stratospheric Observatory for Infrared Astronomy (SOFIA)

    Science.gov (United States)

    Glaser, Scott T.; Strovers, Brian K.

    2011-01-01

    Airborne infrared astronomy has a long successful history, albeit relatively unknown outside of the astronomy community. A major problem with ground based infrared astronomy is the absorption and scatter of infrared energy by water in the atmosphere. Observing the universe from above 40,000 ft puts the observation platform above 99% of the water vapor in the atmosphere, thereby addressing this problem at a fraction of the cost of space based systems. The Stratospheric Observatory For Infrared Astronomy (SOFIA) aircraft is the most ambitious foray into the field of airborne infrared astronomy in history. Using a 747SP (The Boeing Company, Chicago, Illinois) aircraft modified with a 2.5m telescope located in the aft section of the fuselage, the SOFIA endeavors to provide views of the universe never before possible and at a fraction of the cost of space based systems. The modification to the airplane includes moveable doors and aperture that expose the telescope assembly. The telescope assembly is aimed and stabilized using a multitude of on board systems. This modification has the potential to cause aerodynamic anomalies that could induce undesired forces either at the cavity itself or indirectly due to interference with the empennage, both of which could cause handling qualities issues. As a result, an extensive analysis and flight test program was conducted from December 2009 through March 2011. Several methods, including a Lower Order Equivalent Systems analysis and pilot assessment, were used to ascertain the effects of the modification. The SOFIA modification was found to cause no adverse handling qualities effects and the aircraft was cleared for operational use. This paper discusses the history and modification to the aircraft, development of test procedures and analysis, results of testing and analysis, lessons learned for future projects and justification for operational certification.