WorldWideScience

Sample records for aircraft crash impact

  1. Classification of soft and hard impacts-Application to aircraft crash

    International Nuclear Information System (INIS)

    Before modeling an aircraft crash on a shield building of a nuclear power plant, it is very important to understand the physical phenomena and the structural behavior associated with this kind of impact. In the scientific literature, aircraft crash is classified as a soft impact, or as an impact of deformable missile. Nevertheless the existing classifications are not precise enough to be able to predict 'a priori' the structural response mode. The aim of this paper is to characterize very precisely what is a soft and a hard impact in the frame of aircraft crash on nuclear power plant. First the existing qualitative definition of soft and hard impact is quickly reviewed in order to introduce a new criterion to make a quantitative distinction between soft and hard impact. Then the experimental tests carried out during the last thirty years in the research field of aircraft crash are presented in the light of the new classification. The authors show that this characterization of soft and hard impacts has a real physical interest because it is linked to the failure mode for perforation: for soft impacts, perforation is the consequence of a shear plug breaking away and for hard impact it comes from local failure and projectile penetration. Moreover the boundary between soft and hard impact is the limit for the use of an impact force in an uncoupled computation of the impact

  2. Impact Analyses and Tests of Metal Cask Considering Aircraft Engine Crash - 12308

    International Nuclear Information System (INIS)

    The structural integrity of a dual purpose metal cask currently under development by the Korea Radioactive Waste Management Cooperation (KRMC) is evaluated through analyses and tests under a high-speed missile impact considering the targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from the literature. The missile impact velocity was set at 150 m/s, and two impact orientations were considered. A simplified missile simulating a commercial aircraft engine is designed from an impact load history curve provided in the literature. In the analyses, the focus is on the evaluation of the containment boundary integrity of the metal cask. The analyses results are compared with the results of tests using a 1/3 scale model. The results show very good agreements, and the procedure and methodology adopted in the structural analyses are validated. While the integrity of the cask is maintained in one evaluation where the missile impacts the top side of the free standing cask, the containment boundary is breached in another case in which the missile impacts the center of the cask lid in a perpendicular orientation. A safety assessment using a numerical simulation of an aircraft engine crash into spent nuclear fuel storage systems is performed. A commercially available explicit finite element code is utilized for the dynamic simulation, and the strain rate effect is included in the modeling of the materials used in the target system and missile. The simulation results show very good agreement with the test results. It is noted that this is the first test considering an aircraft crash in Korea. (authors)

  3. Safety margins of spent fuel transport and storage casks considering aircraft crash impacts

    International Nuclear Information System (INIS)

    The safety of spent fuel transport casks in severe accident conditions is always a matter of concern. This paper surveys German missile impact tests that have been carried out in the past to demonstrate that German cask designs for transport and interim storage are safe even under conditions of an aircraft crash impact. A fire test with a cask beside an exploding propane vessel and temperature calculations concerning prolonged fires also show that the casks have reasonably good safety margins in thermal accidents beyond regulatory fire test conditions. (author)

  4. Analysis of Aircraft Crash Accident for WETF

    International Nuclear Information System (INIS)

    This report applies the methodology of DOE-STD-3014-96, ''Accident Analysis for Aircraft Crash into Hazardous Facilities'', to the Weapons Engineering Tritium Facility (WETF) at LANL. Straightforward application of that methodology shows that including local helicopter flights with those of all other aircraft with potential to impact the facility poses a facility impact risk slightly in excess of the DOE standard's threshold--10-6 impacts per year. It is also shown that helicopters can penetrate the facility if their engines impact that facility's roof. However, a refinement of the helicopter impact analysis shows that penetration risk of the facility for all aircraft lies below the DOE standard's threshold. By that standard, therefore, the potential for release of hazardous material from the facility as a result of an aircraft crashing into the facility is negligible and need not be analyzed further

  5. Structural evaluation of spent nuclear fuel storage facilities under aircraft crash impact. Numerical study on evaluation of sealing performance of metal cask subjected to impact force

    International Nuclear Information System (INIS)

    A lot of safety evaluations on the important nuclear facilities against the aircraft crash have been reported in other countries. But the condition and the evaluation method to define impact force of aircraft crash have not been described clearly in the reports. In Japan, public concern with the safety evaluation against aircraft crash is increasing. It is important to make clear the behavior of the storage facilities installing the metal casks on impact loading due to aircraft crash. In this study, concerning crash between commercial aircraft and storage facility, impact analysis using dynamic analysis code LS-DYNA has been executed. The results showed that the storage facility was not completely destroyed. But the rigid aircraft engine may penetrate into the storage facility with local failure. Thus, we assumed the engine hit a metal cask in the storage facility and evaluated sealing performance of the metal cask under the impact loading. If the engine with 90m/s crashed the storage facility having concrete wall of 85cm in thickness, the remaining velocity became 60m/s after penetration. We calculated impact force of the engine with 60m/s crashing into the metal cask. Concerning the metal cask loaded the impact force, impact analysis was executed. We assumed two directions of impact force. One is vertical load and another is horizontal load against the cask. The result showed that plastic strain was not generated on flanges of the 1st lid and the sealing performance of the cask was maintained in each impact case. (author)

  6. Offsite radiological consequence analysis for the bounding aircraft crash accident

    International Nuclear Information System (INIS)

    The purpose of this calculation note is to quantitatively analyze a bounding aircraft crash accident for comparison to the DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', Appendix A, Evaluation Guideline of 25 rem. The potential of aircraft impacting a facility was evaluated using the approach given in DOE-STD-3014-96, ''Accident Analysis for Aircraft Crash into Hazardous Facilities''. The following aircraft crash FR-equencies were determined for the Tank Farms in RPP-11736, ''Assessment Of Aircraft Crash FR-equency For The Hanford Site 200 Area Tank Farms'': (1) The total aircraft crash FR-equency is ''extremely unlikely.'' (2) The general aviation crash FR-equency is ''extremely unlikely.'' (3) The helicopter crash FR-equency is ''beyond extremely unlikely.'' (4) For the Hanford Site 200 Areas, other aircraft type, commercial or military, each above ground facility, and any other type of underground facility is ''beyond extremely unlikely.'' As the potential of aircraft crash into the 200 Area tank farms is more FR-equent than ''beyond extremely unlikely,'' consequence analysis of the aircraft crash is required

  7. Accident analysis for aircraft crash into hazardous facilities: DOE standard

    International Nuclear Information System (INIS)

    This standard provides the user with sufficient information to evaluate and assess the significance of aircraft crash risk on facility safety without expending excessive effort where it is not required. It establishes an approach for performing a conservative analysis of the risk posed by a release of hazardous radioactive or chemical material resulting from an aircraft crash into a facility containing significant quantities of such material. This can establish whether a facility has a significant potential for an aircraft impact and whether this has the potential for producing significant offsite or onsite consequences. General implementation guidance, screening and evaluation guidelines, and methodologies for the evaluations are included

  8. Crash Impact Demonstration. (pt 6/10)

    Science.gov (United States)

    1984-01-01

    This clip: Cockpit interior. Showing the pilot during impact, view forward. With narration. Background: On December 1st, 1984, a remote controlled 4 engined transport jet took off from Edwards AFB, CA and crashed into a barren patch of nearby desert. This Controlled Impact Demonstration was a joint R&D program by the FAA and NASA. The FAA designed the C.I.D. to underscore results of exhaustive research in two areas of aircraft safety: improved crash protection and reduced post-crash fire hazards.Despite the fact the crash did not go exactly as designed C.I.D.did achieve its primary objectives.The analysis of C.I.D. data continues. The CID's crash wothiness tests were as important to the FAA as the fire safety tests. The crash protection objectives were: 1st: To obtain data on impact forces and their transmission thru the structure to the seats and occupants. 2nd: To evaluate the performance of existing and advanced energy absorbing seats. 3rd :To compare tests used to predict structural behaviour with an actual crash. AMK (anti-misting kerosene) fuel was employed in the test. The FAA has examined AMK's potential for protecting commercial transports from ignition of misted fuels. All research indicated that AMK would be effective in preventing this problem. The C.I.D. was an opportunity to use AMK in a realistic, impact-survivable crash.

  9. Crash Impact Demonstration. (pt 7/10)

    Science.gov (United States)

    1984-01-01

    This clip: Montage of several different views thru the duration of impact. With narration. Background: On December 1st, 1984, a remote controlled 4 engined transport jet took off from Edwards AFB, CA and crashed into a barren patch of nearby desert. This Controlled Impact Demonstration was a joint R&D program by the FAA and NASA. The FAA designed the C.I.D. to underscore results of exhaustive research in two areas of aircraft safety: improved crash protection and reduced post-crash fire hazards.Despite the fact the crash did not go exactly as designed C.I.D.did achieve its primary objectives.The analysis of C.I.D. data continues. The CID's crash wothiness tests were as important to the FAA as the fire safety tests. The crash protection objectives were: 1st: To obtain data on impact forces and their transmission thru the structure to the seats and occupants. 2nd: To evaluate the performance of existing and advanced energy absorbing seats. 3rd :To compare tests used to predict structural behaviour with an actual crash. AMK (anti-misting kerosene) fuel was employed in the test. The FAA has examined AMK's potential for protecting commercial transports from ignition of misted fuels. All research indicated that AMK would be effective in preventing this problem. The C.I.D. was an opportunity to use AMK in a realistic, impact-survivable crash.

  10. Crash Impact Demonstration. (pt 3/10)

    Science.gov (United States)

    1984-01-01

    This clip: Extreme Long shot of impact showing the huge fireball surrounding the airplane. With narration. Background: On December 1st, 1984, a remote controlled 4 engined transport jet took off from Edwards AFB, CA and crashed into a barren patch of nearby desert. This Controlled Impact Demonstration was a joint R&D program by the FAA and NASA. The FAA designed the C.I.D. to underscore results of exhaustive research in two areas of aircraft safety: improved crash protection and reduced post-crash fire hazards.Despite the fact the crash did not go exactly as designed C.I.D.did achieve its primary objectives.The analysis of C.I.D. data continues. The CID's crash wothiness tests were as important to the FAA as the fire safety tests. The crash protection objectives were: 1st: To obtain data on impact forces and their transmission thru the structure to the seats and occupants. 2nd: To evaluate the performance of existing and advanced energy absorbing seats. 3rd :To compare tests used to predict structural behaviour with an actual crash. AMK (anti-misting kerosene) fuel was employed in the test. The FAA has examined AMK's potential for protecting commercial transports from ignition of misted fuels. All research indicated that AMK would be effective in preventing this problem. The C.I.D. was an opportunity to use AMK in a realistic, impact-survivable crash.

  11. Damage assessment of nuclear containment against aircraft crash

    International Nuclear Information System (INIS)

    Highlights: • Damage assessment of nuclear containment is studied against aircraft crash. • Four impact locations have been identified at the outer containment shell. • The mid of the total height has been found to be most vulnerable location. • The crown of dome has been found to be the strongest location. • Phantom F4 caused more localized and severe damage compared to other aircrafts. - Abstract: The behavior of nuclear containment structure has been studied against aircraft crash with an emphasis on the influence of strike location. The impact locations identified on the BWR Mark III type nuclear containment structure are mid-height, junction of dome and cylinder, crown of dome and arc of dome. The containment at each of the above locations has been impacted normally by Phantom F-4, Boeing 707-320 and Airbus A320 aircrafts. The loading of the aircraft has been assigned through the corresponding reaction-time response curve. ABAQUS/Explicit finite element code has been used to carry out the three-dimensional numerical simulations. The concrete damaged plasticity model was used to simulate the behavior of concrete while the behavior of steel reinforcement was incorporated using the Johnson–Cook elasto-viscoplastic material model. The mid-height of containment has been found to experience most severe deformation against each aircraft. Phantom F4 has been found to be most disastrous at each location. The results have been compared with those of the available studies with respect to the containment deformation

  12. Damage assessment of nuclear containment against aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Mohd Ashraf, E-mail: iqbal_ashraf@rediffmail.com; Sadique, Md. Rehan, E-mail: rehan.sadique@gmail.com; Bhargava, Pradeep, E-mail: bhpdpfce@iitr.ac.in; Bhandari, N.M., E-mail: nmbcefce@iitr.ac.in

    2014-10-15

    Highlights: • Damage assessment of nuclear containment is studied against aircraft crash. • Four impact locations have been identified at the outer containment shell. • The mid of the total height has been found to be most vulnerable location. • The crown of dome has been found to be the strongest location. • Phantom F4 caused more localized and severe damage compared to other aircrafts. - Abstract: The behavior of nuclear containment structure has been studied against aircraft crash with an emphasis on the influence of strike location. The impact locations identified on the BWR Mark III type nuclear containment structure are mid-height, junction of dome and cylinder, crown of dome and arc of dome. The containment at each of the above locations has been impacted normally by Phantom F-4, Boeing 707-320 and Airbus A320 aircrafts. The loading of the aircraft has been assigned through the corresponding reaction-time response curve. ABAQUS/Explicit finite element code has been used to carry out the three-dimensional numerical simulations. The concrete damaged plasticity model was used to simulate the behavior of concrete while the behavior of steel reinforcement was incorporated using the Johnson–Cook elasto-viscoplastic material model. The mid-height of containment has been found to experience most severe deformation against each aircraft. Phantom F4 has been found to be most disastrous at each location. The results have been compared with those of the available studies with respect to the containment deformation.

  13. Nuclear containment structure subjected to commercial and fighter aircraft crash

    International Nuclear Information System (INIS)

    Highlights: • Nuclear containment response has been studied against aircraft crash. • Concrete damaged plasticity and Johnson–Cook elasto-viscoplastic models were employed. • Boeing 747-400 and Boeing 767-400 aircrafts caused global failure of containment. • Airbus A320 and Boeing 707-320 aircrafts caused local damage. • Tension damage of concrete was found more prominent compared to compression damage. -- Abstract: The response of a boiling water reactor (BWR) nuclear containment vessel has been studied against commercial and fighter aircraft crash using a nonlinear finite element code ABAQUS. The aircrafts employed were Boeing 747-400, Boeing 767-400, Airbus A-320, Boeing 707-320 and Phantom F4. The containment was modeled as a three-dimensional deformable reinforced concrete structure while the loading of aircraft was assigned using the respective reaction–time curve. The location of strike was considered near the junction of dome and cylinder, and the angle of incidence, normal to the containment surface. The material behavior of the concrete was incorporated using the damaged plasticity model while that of the reinforcement, the Johnson–Cook elasto-viscoplastic model. The containment could not sustain the impact of Boeing 747-400 and Boeing 767-400 aircrafts and suffered rupture of concrete around the impact region leading to global failure. On the other hand, the maximum local deformation at the point of impact was found to be 0.998 m, 0.099 m, 0.092 m, 0.089 m, and 0.074 m against Boeing 747-400, Phantom F4, Boeing 767, Boeing 707-320 and Airbus A-320 aircrafts respectively. The results of the present study were compared with those of the previous analytical and numerical investigations with respect to the maximum deformation and overall behavior of the containment

  14. Nuclear containment structure subjected to commercial and fighter aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Sadique, M.R., E-mail: rehan.sadique@gmail.com; Iqbal, M.A., E-mail: iqbalfce@iitr.ernet.in; Bhargava, P., E-mail: bhpdpfce@iitr.ernet.in

    2013-07-15

    Highlights: • Nuclear containment response has been studied against aircraft crash. • Concrete damaged plasticity and Johnson–Cook elasto-viscoplastic models were employed. • Boeing 747-400 and Boeing 767-400 aircrafts caused global failure of containment. • Airbus A320 and Boeing 707-320 aircrafts caused local damage. • Tension damage of concrete was found more prominent compared to compression damage. -- Abstract: The response of a boiling water reactor (BWR) nuclear containment vessel has been studied against commercial and fighter aircraft crash using a nonlinear finite element code ABAQUS. The aircrafts employed were Boeing 747-400, Boeing 767-400, Airbus A-320, Boeing 707-320 and Phantom F4. The containment was modeled as a three-dimensional deformable reinforced concrete structure while the loading of aircraft was assigned using the respective reaction–time curve. The location of strike was considered near the junction of dome and cylinder, and the angle of incidence, normal to the containment surface. The material behavior of the concrete was incorporated using the damaged plasticity model while that of the reinforcement, the Johnson–Cook elasto-viscoplastic model. The containment could not sustain the impact of Boeing 747-400 and Boeing 767-400 aircrafts and suffered rupture of concrete around the impact region leading to global failure. On the other hand, the maximum local deformation at the point of impact was found to be 0.998 m, 0.099 m, 0.092 m, 0.089 m, and 0.074 m against Boeing 747-400, Phantom F4, Boeing 767, Boeing 707-320 and Airbus A-320 aircrafts respectively. The results of the present study were compared with those of the previous analytical and numerical investigations with respect to the maximum deformation and overall behavior of the containment.

  15. Aircraft crash analysis of the proposed sizewell B containment vessel

    International Nuclear Information System (INIS)

    This paper attempts to examine the behaviour of the proposed sizewell B containment vessel under the impact of a multi-role combat aircraft such as a Tornado and Phantom RF-4E. A 600 section of the containment vessel is analysed using three dimensional 20 noded isoparametric finite elements adopted in Program CRASH. The impact area under consideration is 28 m2 which is evaluated from the data obtained from these two aircraft. The vessel is assumed to have unbonded tendons both in the dome and in the barrel wall. The influence of the liner is included in evaluating resistance to the impact. A three-dimensional time dependent impact analysis is carried out which incorporates, direct integration concept. The final results obtained include displacements, velocities, accelerations; concrete scabbing, perforation and general cracking. The final damage is shown in a specially prepared post-mortem diagram. The paper has an appendix summarising the constitutive equations for the proposed numerical model. (orig.)

  16. Structural Integrity Assessment of Reactor Containment Subjected to Aircraft Crash

    International Nuclear Information System (INIS)

    When an accident occurs at the NPP, containment building which acts as the last barrier should be assessed and analyzed structural integrity by internal loading or external loading. On many occasions that can occur in the containment internal such as LOCA(Loss Of Coolant Accident) are already reflected to design. Likewise, there are several kinds of accidents that may occur from the outside of containment such as earthquakes, hurricanes and strong wind. However, aircraft crash that at outside of containment is not reflected yet in domestic because NPP sites have been selected based on the probabilistic method. After intentional aircraft crash such as World Trade Center and Pentagon accident in US, social awareness for safety of infrastructure like NPP was raised world widely and it is time for assessment of aircraft crash in domestic. The object of this paper is assessment of reactor containment subjected to aircraft crash by FEM(Finite Element Method). In this paper, assessment of structural integrity of containment building subjected to certain aircraft crash was carried out. Verification of structure integrity of containment by intentional severe accident. Maximum stress 61.21MPa of horizontal shell crash does not penetrate containment. Research for more realistic results needed by steel reinforced concrete model

  17. Estimate of aircraft crash hit frequencies on to facilities at the Lawrence Livermore National Laboratory (LLNL) Site 200

    International Nuclear Information System (INIS)

    Department of Energy (DOE) nuclear facilities are required by DOE Order 5480.23, Section 8.b.(3)(k) to consider external events as initiating events to accidents within the scope of their Safety Analysis Reports (SAR). One of the external initiating events which should be considered within the scope of a SAR is an aircraft accident, i.e., an aircraft crashing into the nuclear facility with the related impact and fire leading to penetration of the facility and to the release of radioactive and/or hazardous materials. This report presents the results of an Aircraft Crash Frequency analysis performed for the Materials Management Area (MMA), and the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) Site 200. The analysis estimates only the aircraft crash hit frequency on to the analyzed facilities. No initial aircraft crash hit frequency screening structural response calculations of the facilities to the aircraft impact, or consequence analysis of radioactive/hazardous materials released following the aircraft impact are performed. The method used to estimate the aircraft crash hit frequencies on to facilities at the Lawrence Livermore National Laboratory (LLNL) generally follows the procedure given by the DOE Standard 3014-96 on Aircraft Crash Analysis. However, certain adjustments were made to the DOE Standard procedure because of the site specific fight environment or because of facility specific characteristics

  18. Nonlinear analysis of commercial aircraft impact on a reactor building—Comparison between integral and decoupled crash simulation

    International Nuclear Information System (INIS)

    Since 9/11, the crash of a commercial aeroplane on the reactor building of a nuclear power plant is a realistic design scenario. Before that the structural behaviour under a crash of a military plane was investigated by a procedure using load-time functions (Riera, 1968). Thereby, the computation of the load-time-function was based on a conceptional model considering the main stiffness parts and masses by discrete elements. With respect to the homogeneous structural set-up of a military plane, the application of this model and the derived load-time-function applied as lumped load case seems very feasible. Contrary thereto the structural set-up of a commercial aeroplane, with e.g. the high mass concentration of the turbine or the high stiffness of the wing box compared to other parts, is different. This can be counteracted by using a more detailed finite element (FE) model for the computation of the load-time-function and by dividing the load case for the reactor building in different main load zones. Although this represents a more detailed investigation, the procedure of using a load-time-function still has the disadvantage to separate the real scenario into two steps. Thereby, the direct interaction between the structure and the aeroplane including all softening effects due to material respectively structural compliances is neglected. This leads to the general conclusion that by applying load-time-functions the results are conservative compared to the real behaviour. Due to the increased capabilities of numerical software solutions it is also possible nowadays to carry out integral crash simulations, combining all effects within one simulation. Compared to the procedure of using load-time-functions, the numerical complexity and therefore the amount of work for this integral method are increased. Within this paper both procedures (load-time function by detailed FE-model and the integral method) are exemplarily compared to each other by a crash analysis of an

  19. Experimental Photogrammetric Techniques Used on Five Full-Scale Aircraft Crash Tests

    Science.gov (United States)

    Littell, Justin D.

    2016-01-01

    Between 2013 and 2015, full-scale crash tests were conducted on five aircraft at the Landing and Impact Research Facility (LandIR) at NASA Langley Research Center (LaRC). Two tests were conducted on CH-46E airframes as part of the Transport Rotorcraft Airframe Crash Testbed (TRACT) project, and three tests were conduced on Cessna 172 aircraft as part of the Emergency Locator Transmitter Survivability and Reliability (ELTSAR) project. Each test served to evaluate a variety of crashworthy systems including: seats, occupants, restraints, composite energy absorbing structures, and Emergency Locator Transmitters. As part of each test, the aircraft were outfitted with a variety of internal and external cameras that were focused on unique aspects of the crash event. A subset of three camera was solely used in the acquisition of photogrammetric test data. Examples of this data range from simple two-dimensional marker tracking for the determination of aircraft impact conditions to entire full-scale airframe deformation to markerless tracking of Anthropomorphic Test Devices (ATDs, a.k.a. crash test dummies) during the crash event. This report describes and discusses the techniques used and implications resulting from the photogrammetric data acquired from each of the five tests.

  20. Information note about the protection of nuclear facilities against aircraft crashes

    International Nuclear Information System (INIS)

    The protection of nuclear facilities against external risks (earthquakes, floods, fires etc..) is an aspect of safety taken into consideration by the French authority of nuclear safety (ASN). Concerning the aircraft crashes, the fundamental safety rules make three categories of aircraft: the small civil aircraft (weight 5.7 t). Nuclear facilities are designed to resist against crashes of aircraft from the first category only, because the probability of the accidental crash of a big aircraft are extremely low. This document comprises an information note about the protection of nuclear facilities against aircraft crashes, a dossier about the safety of nuclear facilities with respect to external risks in general (natural disasters and aircraft crashes), and an article about the protection of nuclear power plants against aircraft crashes (design, safety measures, regulation, surveillance, experience feedback). (J.S.)

  1. Assessment of the consequences of aircraft crashes on a PWR power plant (as applied to Sizewell B)

    International Nuclear Information System (INIS)

    The study analyses the probability of severe core damage and an uncontrolled release of radioactivity in the event of a postulated crash of a military combat aircraft on the central buildings of the proposed Sizewell-B pressurized water reactor. The study identifies a number of regional damage states which would arise as the result of such a crash. The probabilities of damage states are estimated on the basis of building geometries and resistance to impacts and the distribution of aircraft crash energies and angles in the vicinity of the site. For each regional damage state the surviving equipment is compared with the minimum requirements for reactor core control and from this comparison, probabilities of core damage are estimated using simple functional event trees. It is concluded that it is unreasonably pessimistic to assume that an aircraft crash onto Sizewell-B would lead inevitably to a core meltdown or uncontrolled release of radioactivity. (U.K.)

  2. Preliminary Study on Effect of Aviation Fuel in the Safety Evaluation of Nuclear Power Plant Crashed by Aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Byeong Moo; Jeon, Se Jin; Lee, Yun Seok; Kim, Young Jin [Daewoo E and C Co., Suwon (Korea, Republic of)

    2011-10-15

    As the safety assessments of nuclear power plants for the hypothetical large civil aircraft crash should be made mandatory, studies on large aircraft-nuclear power plant impact analyses and assessments are actively in progress. The large civil aircraft are being operated with a large amount of fuel and the fuel can be assumed to contribute to the impact loads at the impact. The fuel, i.e., the internal liquid can be considered as added masses classically in the evaluation of the impact load. According to the recent experimental research, it has been shown that the impact load of high speed impacting body with internal liquid is much higher than that of the mass-equivalent impacting body. In this study, the impact loads according to the existence of the internal liquid are computed by numerical methods and the safety assessment of nuclear power plant crashed by large civil aircraft are performed as an application

  3. A Perspective into Regulatory Requirements for Intentional Aircraft Crash

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Yun; Park, Jong Seuk; Chung, Yun Suk [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Inn Seock [ISSA Technology, Maryland (Korea, Republic of); Choi, Eong Soo; Kim, Jong Hyun [ACT Co., Daejeon (Korea, Republic of)

    2010-10-15

    In the aftermath of the 9/11 terrorist attacks on the United States, there was heightened interest worldwide in protecting nuclear power plants against intentional aircraft attack by terrorists. This paper presents our perspective into regulatory requirements for intentional aircraft crash that were set forth in foreign countries, including the latest rulemaking by the U.S. Nuclear Regulatory Commission (NRC), i.e., 10 CFR 50.54(hh) and 10 CFR 50.150 that have been made effective in May and July of 2009, respectively. In light of these international efforts to further enhance safety of NPPs, a study is also underway at the Korea Institute of Nuclear Safety (KINS) to establish an effective and efficient regulatory approach in consideration of the state of the art in this area

  4. A Perspective into Regulatory Requirements for Intentional Aircraft Crash

    International Nuclear Information System (INIS)

    In the aftermath of the 9/11 terrorist attacks on the United States, there was heightened interest worldwide in protecting nuclear power plants against intentional aircraft attack by terrorists. This paper presents our perspective into regulatory requirements for intentional aircraft crash that were set forth in foreign countries, including the latest rulemaking by the U.S. Nuclear Regulatory Commission (NRC), i.e., 10 CFR 50.54(hh) and 10 CFR 50.150 that have been made effective in May and July of 2009, respectively. In light of these international efforts to further enhance safety of NPPs, a study is also underway at the Korea Institute of Nuclear Safety (KINS) to establish an effective and efficient regulatory approach in consideration of the state of the art in this area

  5. Numerical simulation of aircraft crash on nuclear containment structure

    International Nuclear Information System (INIS)

    Highlights: ► The deformation was more localised at the center of cylindrical portion. ► The peak deflection at the junction of dome and cylinder was found to be 67 mm. ► The peak deflection at midpoint of the cylindrical portion was found to be 88.9 mm. ► The strain rate was found to be an important parameter to effect the deformation. ► The model without strain rate and 290 s−1 strain rate predicted very high deformations. - Abstract: Numerical simulations were carried with ABAQUS/Explicit finite element code in order to predict the response of BWR Mark III type nuclear containment against Boeing 707-320 aircraft crash. The load of the aircraft was applied using and force history curve. The damaged plasticity model was used to predict the behavior of concrete while the Johnson–Cook elasto-viscoplastic material model was used to incorporate the behavior of steel reinforcement. The crash was considered to occur at two different locations i.e., the midpoint of the cylindrical portion and the junction of dome and cylinder. The midpoint of the cylindrical portion experienced more deformation. The strain rate in the material model was varied and found to have a significant effect on the response of containment. The results of the present investigation were compared with those of the studies available in literature and a close agreement with the previous results was found in terms of maximum target deformation.

  6. Assessment of aircraft crash FR-equency for the Hanford site 200 Area tank farms

    International Nuclear Information System (INIS)

    Two factors, the near-airport crash FR-equency and the non-airport crash FR-equency, enter into the estimate of the annual aircraft crash FR-equency at a facility. The near-airport activities, Le., takeoffs and landings FR-om any of the airports in a 23-statute-mile (smi) (20-nautical-mile, [nmi]) radius of the facilities, do not significantly contribute to the annual aircraft crash FR-equency for the 200 Area tank farms. However, using the methods of DOE-STD-3014-96, the total FR-equency of an aircraft crash for the 200 Area tank farms, all FR-om non-airport operations, is calculated to be 7.10E-6/yr. Thus, DOE-STD-3014-96 requires a consequence analysis for aircraft crash. This total FR-equency consists of contributions FR-om general aviation, helicopter activities, commercial air carriers and air taxis, and FR-om large and small military aircraft. The major contribution to this total is FR-om general aviation with a FR-equency of 6.77E-6/yr. All other types of aircraft have less than 1E-6/yr crash FR-equencies. The two individual aboveground facilities were in the realm of 1E-7/yr crash FR-equencies: 204-AR Waste Unloading Facility at 1.56E-7, and 242-T Evaporator at 8.62E-8. DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', states that external events, such as aircraft crashes, are referred to as design basis accidents (DBA) and analyzed as such: ''if FR-equency of occurrence is estimated to exceed 10-6/yr conservatively calculated'' DOE-STD-3014-96 considers its method for estimating aircraft crash FR-equency as being conservative. Therefore, DOE-STD-3009-94 requires DBA analysis of an aircraft crash into the 200 Area tank farms. DOE-STD-3009-94 also states that beyond-DBAs are not evaluated for external events. Thus, it requires only a DBA analysis of the effects of an aircraft crash into the 200 Area tank farms. There are two attributes of an aircraft crash into a Hanford waste

  7. Assessment of the probability of an aircraft accidentally crashing on a nuclear power station

    International Nuclear Information System (INIS)

    The probability of an accidental aircraft crash on a power station not situated near a commercial airport is assessed. Three major points in the general analysis of the problem are developed: analysis of accidents as a function of the phase of the flight and in particular during a flight in transit and examin-ation of aircraft crash conditions to determine the angle of impact on the reactor building for example; determination of the apparent surface of buildings allowing for several parameters: geometry of the building and of the aircraft, geography of the site, relative position of the buildings; assessment of air traffic above the region for the year under consideration distinguishing the weight of the aircraft which implies an investigation of the problem for commercial aviation on the one hand (regular or irregular flights, inter-national or internal) and for general aviation on the other hand. The analysis is determined for the years 1980 - 2000 so that ir will be necessary to extrapolate some of the parameters (development of air traffic, safety of transport, etc). (author)

  8. Numerical simulation of aircraft crash on nuclear containment structure

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, M.A., E-mail: iqbalfce@iitr.ernet.in [Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Rai, S.; Sadique, M.R.; Bhargava, P. [Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer The deformation was more localised at the center of cylindrical portion. Black-Right-Pointing-Pointer The peak deflection at the junction of dome and cylinder was found to be 67 mm. Black-Right-Pointing-Pointer The peak deflection at midpoint of the cylindrical portion was found to be 88.9 mm. Black-Right-Pointing-Pointer The strain rate was found to be an important parameter to effect the deformation. Black-Right-Pointing-Pointer The model without strain rate and 290 s{sup -1} strain rate predicted very high deformations. - Abstract: Numerical simulations were carried with ABAQUS/Explicit finite element code in order to predict the response of BWR Mark III type nuclear containment against Boeing 707-320 aircraft crash. The load of the aircraft was applied using and force history curve. The damaged plasticity model was used to predict the behavior of concrete while the Johnson-Cook elasto-viscoplastic material model was used to incorporate the behavior of steel reinforcement. The crash was considered to occur at two different locations i.e., the midpoint of the cylindrical portion and the junction of dome and cylinder. The midpoint of the cylindrical portion experienced more deformation. The strain rate in the material model was varied and found to have a significant effect on the response of containment. The results of the present investigation were compared with those of the studies available in literature and a close agreement with the previous results was found in terms of maximum target deformation.

  9. Crash Testing and Simulation of a Cessna 172 Aircraft: Hard Landing Onto Concrete

    Science.gov (United States)

    Jackson, Karen E.; Fasanella, Edwin L.

    2016-01-01

    A full-scale crash test of a Cessna 172 aircraft was conducted at the Landing and Impact Research Facility at NASA Langley Research Center during the summer of 2015. The purpose of the test was to evaluate the performance of Emergency Locator Transmitters (ELTs) that were mounted at various locations in the aircraft and to generate impact test data for model validation. A finite element model of the aircraft was developed for execution in LSDYNA to simulate the test. Measured impact conditions were 722.4-in/s forward velocity and 276-in/s vertical velocity with a 1.5deg pitch (nose up) attitude. These conditions were intended to represent a survivable hard landing. The impact surface was concrete. During the test, the nose gear tire impacted the concrete, followed closely by impact of the main gear tires. The main landing gear spread outward, as the nose gear stroked vertically. The only fuselage contact with the impact surface was a slight impact of the rearmost portion of the lower tail. Thus, capturing the behavior of the nose and main landing gear was essential to accurately predict the response. This paper describes the model development and presents test-analysis comparisons in three categories: inertial properties, time sequence of events, and acceleration and velocity time-histories.

  10. Data development technical support document for the aircraft crash risk analysis methodology (ACRAM) standard

    International Nuclear Information System (INIS)

    The Aircraft Crash Risk Analysis Methodology (ACRAM) Panel has been formed by the US Department of Energy Office of Defense Programs (DOE/DP) for the purpose of developing a standard methodology for determining the risk from aircraft crashes onto DOE ground facilities. In order to accomplish this goal, the ACRAM panel has been divided into four teams, the data development team, the model evaluation team, the structural analysis team, and the consequence team. Each team, consisting of at least one member of the ACRAM plus additional DOE and DOE contractor personnel, specializes in the development of the methodology assigned to that team. This report documents the work performed by the data development team and provides the technical basis for the data used by the ACRAM Standard for determining the aircraft crash frequency. This report should be used to provide the generic data needed to calculate the aircraft crash frequency into the facility under consideration as part of the process for determining the aircraft crash risk to ground facilities as given by the DOE Standard Aircraft Crash Risk Assessment Methodology (ACRAM). Some broad guidance is presented on how to obtain the needed site-specific and facility specific data but this data is not provided by this document

  11. Assessment of the fire resistance of a nuclear power plant subjected to a large commercial aircraft crash

    International Nuclear Information System (INIS)

    Highlights: ► A procedure to assess fire resistance of structure for aircraft crash is proposed. ► Fire scenario of containment and auxiliary building is determined for aircraft crash. ► Heat transfer and thermal stress analyses are performed to obtain section forces. ► Fire endurance time is evaluated by load–moment strength interaction diagram. - Abstract: The safety assessment of infrastructures, such as a nuclear power plant, for the crash of a large commercial aircraft has been performed worldwide after the terrorism that occurred in the U.S. on September 11, 2001. The assessment, however, has mainly focused on the techniques of impact analysis. In this study, a systematic procedure to assess the fire resistance of containment and auxiliary buildings subjected to such an aircraft crash is proposed. The intensity, duration and distribution of the fire are determined based on aircraft crash analyses and characteristics of jet fuel. A three-dimensional detailed finite element model of the containment and auxiliary buildings is established and used for heat transfer and thermal stress analyses, taking into account the material properties at an elevated temperature. Section forces can then be obtained that are based on a nonlinear stress–strain relationship. The fire resistance of the structure is assessed by comparing the fire-induced section forces with the section resistance which is evaluated using the load–moment strength interaction diagram. The study addresses the problem whereby the conventional assessment that only considers the flexural behaviour is less accurate. The assessment results support the general conclusion that the nuclear power plant structures can maintain structural integrity against external fire due to their relatively thick sections. The proposed procedure can be extensively applied to evaluate the fire endurance time of any type of structure subjected to an arbitrary fire.

  12. Probabilistic analysis of aircraft crashes with explicit analysis of the building structure perforation; Probabilistische Analyse von Flugzeugabstuerzen mit expliziter Analyse der Perforation von Gebaeudestrukturen

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, Mathias; Pacharzina, Benedykt; Oberste-Schemmann, Andre; Sassen, Felix [Westinghouse Electric Germany GmbH, Mannheim (Germany)

    2012-11-01

    For probabilistic safety analyses (PSA) the estimation of aircraft crash induced core damage frequencies is required. Westinghouse developed a methodology for a realistic evaluation of accident sequences caused by aircraft crashes. The analysis includes two steps: the analysis of sequence of accident events and the analysis of damage mechanisms. For the aircraft crash induced accident sequences new detailed event trees were prepared for application in the PSA. The damage mechanisms include kerosene combustion, by building structures transferred vibrations with direct or mediated effects on safety systems, and direct impacts due to the penetration of building structures. The presented methodology evaluates solely the direct impact by penetration of building structures by simulation of the aircraft crash. It was assumed that the other damage mechanisms do not yield significant contributions to the non-availability of safety system components. It was shown that the calculated core damage frequencies for hypothetical aircraft crashes using the new methodology are about one magnitude lower than the results of conservative methods.

  13. Assessment of methodologies for analysis of the dungeness B accidental aircraft crash risk.

    Energy Technology Data Exchange (ETDEWEB)

    LaChance, Jeffrey L.; Hansen, Clifford W.

    2010-09-01

    The Health and Safety Executive (HSE) has requested Sandia National Laboratories (SNL) to review the aircraft crash methodology for nuclear facilities that are being used in the United Kingdom (UK). The scope of the work included a review of one method utilized in the UK for assessing the potential for accidental airplane crashes into nuclear facilities (Task 1) and a comparison of the UK methodology against similar International Atomic Energy Agency (IAEA), United States (US) Department of Energy (DOE), and the US Nuclear Regulatory Commission (NRC) methods (Task 2). Based on the conclusions from Tasks 1 and 2, an additional Task 3 would provide an assessment of a site-specific crash frequency for the Dungeness B facility using one of the other methodologies. This report documents the results of Task 2. The comparison of the different methods was performed for the three primary contributors to aircraft crash risk at the Dungeness B site: airfield related crashes, crashes below airways, and background crashes. The methods and data specified in each methodology were compared for each of these risk contributors, differences in the methodologies were identified, and the importance of these differences was qualitatively and quantitatively assessed. The bases for each of the methods and the data used were considered in this assessment process. A comparison of the treatment of the consequences of the aircraft crashes was not included in this assessment because the frequency of crashes into critical structures is currently low based on the existing Dungeness B assessment. Although the comparison found substantial differences between the UK and the three alternative methodologies (IAEA, NRC, and DOE) this assessment concludes that use of any of these alternative methodologies would not change the conclusions reached for the Dungeness B site. Performance of Task 3 is thus not recommended.

  14. Safety analysis of dual purpose metal cask subjected to impulsive loads due to aircraft engine crash

    International Nuclear Information System (INIS)

    In Japan, the first Interim Storage Facility of spent nuclear fuel away from reactor site is being planned to start its commercial operation around 2010, in use of dual-purpose metal cask in the northern part of Main Japan Island. Business License Examination for safety design approval has started since March, 2007. To demonstrate the more scientific and rational performance of safety regulation activities on each phase for the first license procedure, CREPEI has executed demonstration tests with full scale casks, such as drop tests onto real targets without impact limiters and seismic tests subjected to strong earthquake motions. Moreover, it is important to develop the knowledge for the inherent security of metal casks under extreme mechanical-impact conditions, especially for increasing interest since the terrorist attacks from 11th September 2001. This paper presents dynamic mechanical behavior of the metal cask lid closure system caused by direct aircraft engine crash and describes calculated results (especially, leak tightness based on relative dynamic displacements between metallic seals). Firstly, the local penetration damage of the interim storage facility building by a big passenger aircraft engine research (diameter 2.7m, length 4.3m, weight 4.4ton, impact velocity 90m/s) has been examined. The reduced velocity is calculated by the local damage formula for concrete structure with its thickness of 70cm. The load vs. time function for this reduced velocity (60m/s) is estimated by the impact analysis using Finite Element code LS-DYNA with the full scale engine model onto a hypothetically rigid target. Secondly, as the most critical scenarios for the metal cask, two impact scenarios (horizontal impact hitting the cask and vertical impact onto the lid metallic seal system) are chosen. To consider the geometry of all bolts for two lids, the gasket reaction forces and the inner pressure of the cask cavity, the detailed three dimensional FEM models are developed

  15. Aircraft impact on a spherical shell

    International Nuclear Information System (INIS)

    For nuclear power plants located in the immediate vicinity of cities and airports safeguarding against an accidental aircraft strike is important. Because of the complexity of such an aircraft crash the building is ordinarily designed for loading by an idealized dynamical load F(t), which follows from measurements (aircraft striking a rigid wall). The extent to which the elastic displacements of a structure influence the impact load F(t) is investigatd in this paper. The aircraft is idealized by a linear mass-spring-dashpot combination which can easily be treated in computations and which can suffer elastic as well as plastic deformations. This 'aircraft' normally strikes a spherical shell at the apex. The time-dependent reactions of the shell as a function of the unknown impact load F(t) are expanded in terms of the normal modes, which are Legendre functions. The continuity condition at the impact point leads to an integral equation for F(t) which may be solved by Laplace transformation. F(t) is computed for hemispheres with several ratios of thickness to radius, several edge conditions and several 'aircraft' parameters. In all cases F(t) differs very little from that function obtained for the case of the aircraft striking a rigid wall. (Auth.)

  16. HTR confinement/containment and the protection against aircraft crash

    International Nuclear Information System (INIS)

    Does an HTR need a containment-pressure resistant-or is it possible- licensable-to have only a so called confinement. The answer depends on both the results of the safety analysis of the accidents considered in the design and the acceptance by the licensing authorities and the public of a safety approach only based on severe core damage exclusion. The safety approach to be developed for modular HTRs must describe the application of the defence in depth principle for such reactors. Whatever the requirements on the last confinement barrier could be, a convincing demonstration of the exclusion of any severe core damage is needed, relying on exhaustive and bounding considerations of severe core damage initiators and the use of non questionable arguments. The paper presents the containment issues for HTRs based on German experience background and considerations for modern modular HTR safety approach including beyond design situations. For the German HTRs (designed in the 80s), it could be shown in the licensing procedures in Germany that there was no need for a pressure retaining and gas tight containment to enclose radioactive nuclides released from the nuclear heat source. Instead, the confinement envelope acted in conjunction with other barriers to minimize the release of radioactive nuclides and the radiological impact on the environment. The confinement envelope consisted of the reactor building, a sub-atmospheric pressure system, a building pressure relief system, an HVAC systems isolation and a filtration system. During a major depressurization accident, unfiltered releases were discharged to the environment. The analyses results show that the environmental impact was far below the dose limits according to the German Radiological Protection Ordinance, even when the effect of filters was not taken into account. The demonstration strongly relied on the assumptions made for the source term definition e. g. the fuel particles failure rates (under irradiation and

  17. Frequency Estimates for Aircraft Crashes into Nuclear Facilities at Los Alamos National Laboratory (LANL)

    Energy Technology Data Exchange (ETDEWEB)

    George D. Heindel

    1998-09-01

    In October 1996, the Department of Energy (DOE) issued a new standard for evaluating accidental aircraft crashes into hazardous facilities. This document uses the method prescribed in the new standard to evaluate the likelihood of this type of accident occurring at Los Alamos National Laboratory's nuclear facilities.

  18. Finite Element Crash Simulations and Impact-Induced Injuries

    Directory of Open Access Journals (Sweden)

    Jaroslav Mackerle

    1999-01-01

    Full Text Available This bibliography lists references to papers, conference proceedings and theses/dissertations dealing with finite element simulations of crashes, impact-induced injuries and their protection that were published in 1980–1998. 390 citations are listed.

  19. Reliability analysis of nuclear containment without metallic liners against jet aircraft crash

    International Nuclear Information System (INIS)

    The present study presents a methodology for detailed reliability analysis of nuclear containment without metallic liners against aircraft crash. For this purpose, a nonlinear limit state function has been derived using violation of tolerable crack width as failure criterion. This criterion has been considered as failure criterion because radioactive radiations may come out if size of crack becomes more than the tolerable crack width. The derived limit state uses the response of containment that has been obtained from a detailed dynamic analysis of nuclear containment under an impact of a large size Boeing jet aircraft. Using this response in conjunction with limit state function, the reliabilities and probabilities of failures are obtained at a number of vulnerable locations employing an efficient first-order reliability method (FORM). These values of reliability and probability of failure at various vulnerable locations are then used for the estimation of conditional and annual reliabilities of nuclear containment as a function of its location from the airport. To study the influence of the various random variables on containment reliability the sensitivity analysis has been performed. Some parametric studies have also been included to obtain the results of field and academic interest.

  20. Accident analysis for aircraft crash into hazardous facilities: A statistical primer

    International Nuclear Information System (INIS)

    The DOE Standard 3014-96, Accident Analysis for Aircraft Crash into Hazardous Facilities provides a robust statistical framework useful for assessing the release frequency for hazardous materials used in many industrial operations. The formulae and the verbal instructions for calculating screening quantities and frequencies in the DOE Standard are consistent with an unstated underlying six-term expression for estimating the annual number of aircraft-impact-related releases. The six-term formula is here shown to result from iterated application of Bayes' rule. The statistical concepts underlying this formula are explained; the six-term model is then developed and its components related to the corresponding elements of the four-factor model presented in the Standard. The six-term model is shown to be consistent with the instructions given in the Standard for calculating the screening and evaluation quantities using the four-factor model. The difference between screening and evaluation of release frequencies is clarified. Discussion of the six-term model shows clearly how conservative approximations to its conditional probability terms lead to simple and efficient screening formulae. A numerical example is provided to demonstrate a screening calculation

  1. Study on nuclear power plant aircraft accidents impacts PSA method

    International Nuclear Information System (INIS)

    Nuclear power plant (NPP) Probabilistic Safety Assessment (PSA) can be divided to internal events PSA and external events PSA. Because of the nature of aircraft accidents impacts, extreme in destroy degree and low frequency, analysts usually treat aircraft impacts as a special external event. There is not any mature method for NPP aircraft impacts PSA. The paper titled Accident For Aircraft Crash Into Analysis Hazardous Facilities is published by U.S. Department of Energy (DOE). The DOE guide could be the main base for this paper, referring to the demand for aircraft impact in NUREG-0800, seeking to develop a particular method for NPP aircraft impacts PSA in China. The method and content in this paper can be applied in similar work and may provide some advices for the future work. (authors)

  2. Aircraft-crash-protected steel reactor building roof structure for the European market

    International Nuclear Information System (INIS)

    This paper recommends the use of all steel roof structures for the reactor building of European Boiling Water Reactor (BWR) plants. This change would make the advanced US BWR designs more compatible with European requirements. Replacement of the existing concrete roof slab with a sufficiently thick steel plate would eliminate the concrete spelling resulting from a postulated aircraft crash, potentially damaging the drywell head or the spent fuel pool

  3. Probabilities of aircraft crashes at Rocky Flats and subsequent radioactive release

    International Nuclear Information System (INIS)

    The probability of a small airplane from Jefferson County Airport (Jeffco) or Stapleton International Airport crashing into a plutonium area at the Rocky Flats Plant has been calculated at 1.4 x 10-4 and 4.2 x 10-6 per year, respectively. The probability of such a crash involving a large airplane from Jeffco or Stapleton is 3.5 x 10-6 and 1.1 x 10-6 per year, respectively. Overall, the chance of an aircraft of any size, or any type, and from any source crashing into a plutonium area at Rocky Flats is 2.88 x 10-4 per year. An event tree was developed to cover every plausible series of events leading to a release of plutonium in the range of 0 to 1000 grams. Selected results show an annual release probability of 3.9 x 10-5 for less than 0.5 grams, 5.8 x 10-6 for 50 to 70 grams, 5.6 x 10-8 for 200 grams, and 6.4 x 10-10 for 1000 grams. Calculations led to a weighted average release amount of 3.7 x 10-4 grams of plutonium per year. Because of conservative assumptions, it is estimated that these probabilities are high by a factor of about two for small aircraft and 10 for large aircraft

  4. Safety design of nuclear power plants against aircraft impacts

    International Nuclear Information System (INIS)

    This paper presents a number of techniques which may be utilized to accomplish the above objectives. Firstly, a re-evaluation is made of aircraft crash probabilities. Secondly, methods are described for calculating aircraft impact forcing functions, for obtaining probability distributions for the impact parameters. Thirdly, evaluations are made for assessing the probability that an impact on a given structure will result in consequences exceeding those listed in 10 CFR 100 and recommendations are made for treating lower consequence events. Finally, other effects such as fires, explosions and secondary missiles are examined briefly

  5. Evaluation of aircraft crash at Laboratorio de Geracao Nucleo-Eletrica (LABGENE) located at Centro Experimental ARAMAR

    International Nuclear Information System (INIS)

    One of the human-induced external hazards to be considered in a Level 1 Probabilistic Safety Assessment for a nuclear plant is the aircraft crash, so it's necessary to have the estimative of the frequency of this hazard. In this paper is obtained the annual frequency of aircraft crash at the Laboratorio de Geracao Nucleo-Eletrica (LABGENE) located at the Centro Experimental ARAMAR (CEA).The calculation of this frequency was based on the method recommended in the Standard Review Plan Section 3.5.1.6 considering the airports, training camps and airways located in CEA's region. The estimated value for the aircraft crash frequency obtained is in accordance with the acceptance criteria established in the Standard Review plan Section 3.5.1.6. (author)

  6. Full-scale aircraft impact test for evaluatioin of impact force

    International Nuclear Information System (INIS)

    For estimating the global elasto-plastic structural response of critical concrete structures subjected to an aircraft crash, the time dependent impact force of a flat rigid barrier against a normally impacting aircraft was first evaluated and then the response, to the impact force, was calculated. In this approach, a significant problem was to determine the impact force for the aircraft against a rigid target. A review of the method proposed to determine the impact forces showed that all were based on analytical methods. However, in these analytical methods, there were many assumptions and many questions remained to be answered. Because of the uncertainty involved in the analytical prediction of the impact force, a full- scale aircraft impact test was performed and an extensive suite of response measurements was obtained. In this paper, these measurements are analyzed to evaluate the impact force accurately. Also, the results were used to evaluate existing analytical methods for prediction of the impact force. 7 refs., 10 figs

  7. Numerical Simulation of Helicopter Cockpit Seat subjected to Crash Impact

    Directory of Open Access Journals (Sweden)

    M.N. Sulaiman

    2013-01-01

    Full Text Available Sikorsky S-61 or better known as “Nuri” had served the Malaysian aviation sector for the past four decades. It is mainly used for transportation, combat search and rescue purposes. However, there were Nuri helicopter crashes or accident cases reported during its operation period which involved loss of its occupants. The pilot survivability rate can be improved provided that the vertical impact loading on the helicopter is reduced during the crash accident. Utilization of an energy absorbing pilot seat or cockpit structure maybe one of the approaches to minimize the impact shock exerted to the occupants. However, the shock or maximum acceleration of the cockpit/pilot seat has to be first determined before a thorough design scheme can be undertaken. In this study, a vertical crash event of the Nuri pilot seat from 500 feet altitude was simulated and the maximum acceleration rate was determined using MSC PATRAN/LSDYNA. The pilot survivability was determined by comparing the result with human tolerance criteria data available in other published works. From the result, it was found that the maximum acceleration of the Nuri pilot seat was 584.4g at 19. 63 milliseconds, thus it can be concluded that the survivability aspect of the pilot is fatal when compared to other published works.

  8. A consideration of hazards, earthquakes, aircraft crashes, explosions and fires in the safety of laboratories and plants

    International Nuclear Information System (INIS)

    Although laboratories and plants differ from nuclear reactors both in their characteristics and sitings, safety measures developed for the hazards of earthquakes, aircraft crashes, explosions and fires are very similar. These measures provide a satisfactory level of safety for these installations

  9. Information note about the protection of nuclear facilities against aircraft crashes; Note d'information sur la protection des installations nucleaires contre les chutes d'avions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The protection of nuclear facilities against external risks (earthquakes, floods, fires etc..) is an aspect of safety taken into consideration by the French authority of nuclear safety (ASN). Concerning the aircraft crashes, the fundamental safety rules make three categories of aircraft: the small civil aircraft (weight < 5.7 t), the military aircraft, and the commercial aircraft (w > 5.7 t). Nuclear facilities are designed to resist against crashes of aircraft from the first category only, because the probability of the accidental crash of a big aircraft are extremely low. This document comprises an information note about the protection of nuclear facilities against aircraft crashes, a dossier about the safety of nuclear facilities with respect to external risks in general (natural disasters and aircraft crashes), and an article about the protection of nuclear power plants against aircraft crashes (design, safety measures, regulation, surveillance, experience feedback). (J.S.)

  10. Dynamic responses of base isolated NPPs under seismic excitations and aircraft crashes

    International Nuclear Information System (INIS)

    Seismic isolation (SI) is a type of seismic design that is based on the concept of reducing the seismic demand rather than increasing the resistance capacity of the structure and related systems. Applying this technology leads to improved performance of structures that will remain essentially elastic during a design basis earthquake. In the application of the system to a nuclear power plant (NPP) structure to gain seismic resistance advantages, other safety issues should also be considered. One of those issues is the safety of an NPP against an aircraft crash (ACC). In this study, responses of a seismically isolated structure, such as acceleration and displacement, were obtained from a time domain non linear analysis to check the performance of SI system under seismic excitation. In addition, the dynamic responses of NPP structures with or without SI against an ACC were compared and other considerations are discussed

  11. Accident-precipitating factors for crashes in turbine-powered general aviation aircraft.

    Science.gov (United States)

    Boyd, Douglas D; Stolzer, Alan

    2016-01-01

    General aviation (14CFR Part 91) accounts for 83% of civil aviation fatalities. While much research has focused on accident causes/pilot demographics in this aviation sector, studies to identify factors leading up to the crash (accident-precipitating factors) are few. Such information could inform on pre-emptive remedial action. With this in mind and considering the paucity of research on turbine-powered aircraft accidents the study objectives were to identify accident-precipitating factors and determine if the accident rate has changed over time for such aircraft operating under 14CFR Part 91. The NTSB Access database was queried for accidents in airplanes (turbine engines and occurring between 1989 and 2013. We developed and utilized an accident-precipitating factor taxonomy. Statistical analyses employed logistic regression, contingency tables and a generalized linear model with Poisson distribution. The "Checklist/Flight Manual Not Followed" was the most frequent accident-precipitating factor category and carried an excess risk (OR 2.34) for an accident with a fatal and/or serious occupant injury. This elevated risk reflected an over-representation of accidents with fatal and/or serious injury outcomes (pturbine aircraft accident rate over the study period was likely due, in part, to a 6-fold increased representation of single engine airplanes. In conclusion, our study is the first to identify novel precursive factors for accidents involving turbine aircraft operating under 14CFR Part 91. This research highlights areas that should receive further emphasis in training/recurrency in a pre-emptive attempt to nullify candidate accident-precipitating factor(s). PMID:26590507

  12. Experimental simulation of a light aircraft crash on to a nuclear power plant auxiliary building roof

    International Nuclear Information System (INIS)

    The experiments described were conducted at a reduced scale with geometric dimensions of prototype structures of one-fifth full size. The target was based on the auxiliary buildings for the proposed Sizewell PWR. Descriptions of the simulated aircraft model and the test panels are given, together with the instrumentation. Details are given of the test programme and the results are summarized and discussed. Comparison is made of the model aircraft tests with an equivalent hard missile impact. (U.K.)

  13. Simulations of Pedestrian Impact Collisions with Virtual CRASH 3 and Comparisons with IPTM Staged Tests

    CERN Document Server

    Becker, Tony; Scurlock, Bob

    2015-01-01

    In this article, we present results from a series of Virtual CRASH-based pedestrian impact simulations. We compare the results of these Virtual CRASH pedestrian impact simulations to data from pedestrian impact collisions staged at the Institute of Police Technology and Management.

  14. Crash simulation of UNS electric vehicle under frontal front impact

    Science.gov (United States)

    Susilo, D. D.; Lukamana, N. I.; Budiana, E. P.; Tjahjana, D. D. D. P.

    2016-03-01

    Sebelas Maret University has been developing an Electric Vehicle namely SmarT-EV UNS. The main structure of the car are chasis and body. The chasis is made from steel and the body is made from fiberglass composite. To ensure the safety of the car, both static and dynamic tests were carried out to these structures, including their materials, like: tensile test, bending test, and impact test. Another test needed by this vehicle is crashworthiness test. To perform the test, it is needed complex equipments and it is quite expensive. Another way to obtain vehicle crashworthiness behaviour is by simulate it. The purpose of this study was to simulate the response of the Smart-EV UNS electric vehicle main structure when crashing rigid barrier from the front. The crash simulation was done in according to the NHTSA (National Highway Traffic Safety Administration) within the speed of the vehicle of 35 mph. The UNS Electric Vehicle was modelled using SolidWorks software, and the simulation process was done by finite element method using ANSYS software. The simulation result showed that the most internal impact energy was absorbed by chassis part. It absorbed 76.2% of impact energy, then the base absorbed 11.3 %, while the front body absorbed 2.5 %, and the rest was absorbed by fender, hood, and other parts.

  15. Floor Response Evaluation for Auxiliary Building Subjected to Aircraft Impact Loading

    International Nuclear Information System (INIS)

    These studies have been aimed to verify and ensure the safety of the targeted walls and structures especially in the viewpoint of the deterministic approach. However, a probabilistic safety assessment as well as deterministic approach for the damage of the internal component in the nuclear power plants (NPPs) subjected to aircraft crash is also needed. A probabilistic safety assessment for aircraft crash includes many uncertainties such as impact velocity, mass, impact location, shape, size, material etc. of aircraft. In this paper, an impact location was selected among the various parameters. This paper found the acceleration floor response spectra at specified locations (safety related components) on the target structure that assumed to be impact velocity 150m/s and maximum fuel for the specified aircraft model. In order to obtain the floor response in case of the crash with a various locations, the analyses for the auxiliary building subjected to aircraft impact were performed using Riera force history method and missile-target interaction method. The difference between responses in case of the building floor subjected to impact was occurred. Thus, in order to obtain the more accurate results, missile-target interaction method was used. This paper found the response at the selected point (node point No. 51). In order to probabilistic assessment for the safety related components, the assessment for a various parameters (velocity, mass, materials etc.) as well as impact locations should be needed

  16. Modelling the Crash Response of Composite Structures

    OpenAIRE

    Johnson, A.; Kohlgrüber, D.

    1997-01-01

    The paper describes recent progress on the materials modelling and numerical simulation of the dynamic crash response of fibre reinforced composite structures. The work is based on the application of explicit finite element analysis codes to composite aircraft structures and structural elements under low velocity impact conditions (up to 15 m/s). Structures studied are designed to absorb crash energy and reduce seat deceleration pulses in aircraft subfloor structures, and consist of an aircra...

  17. Motor vehicle crash-related subdural hematoma from real-world head impact data.

    Science.gov (United States)

    Urban, Jillian E; Whitlow, Christopher T; Edgerton, Colston A; Powers, Alexander K; Maldjian, Joseph A; Stitzel, Joel D

    2012-12-10

    Abstract Approximately 1,700,000 people sustain a traumatic brain injury (TBI) each year and motor vehicle crashes (MVCs) are a leading cause of hospitalization from TBI. Acute subdural hematoma (SDH) is a common intracranial injury that occurs in MVCs associated with high mortality and morbidity rates. In this study, SDH volume and midline shift have been analyzed in order to better understand occupant injury by correlating them to crash and occupant parameters. Fifty-seven head computed tomography (CT) scans were selected from the Crash Injury Research Engineering Network (CIREN) with Abbreviated Injury Scale (AIS) level 3+ SDH. Semi-automated methods were used to isolate the intracranial volume. SDH and additional occupant intracranial injuries were segmented across axial CT images, providing a total SDH injury volume. SDH volume was correlated to crash parameters and occupant characteristics. Results show a positive correlation between SDH volume and crash severity in near-side and frontal crashes. Additionally, the location of the resulting hemorrhage varied by crash type. Those with greater SDH volumes had significantly lower Glasgow Coma Scale (GCS) scores at the crash site in near-side crashes. Age and fracture type were found to be significant contributors to SDH volume. This study is a volumetric analysis of real world brain injuries and known MVC impacts. The results of this study demonstrate a relationship among SDH volume, crash mechanics, and occupant characteristics that provide a better understanding of the injury mechanisms of MVC-associated TBI. PMID:22928543

  18. The impact of crash simulation on productivity and problem-solving in automotive R&D

    OpenAIRE

    Spethmann, Philipp; Thomke, Stefan H.; Herstatt, Cornelius

    2006-01-01

    This paper analyzes the impact of the virtual tool 'crash simulation' on automotive R&D over the last 35 years. The research carried out in this context identifies and investigates distinct phases respectively stages of the potential of crash simulations based on the Finite Element Method and the stages' impact on automotive R&D in-depth. In a study of German Original Equipment Manufacturers' (OEM) utilization of crash simulations, the evolution of this tool is explored and its impact on prod...

  19. Prediction of UHPFRC panels thickness subjected to aircraft engine impact

    Directory of Open Access Journals (Sweden)

    Duc-Kien Thai

    2016-06-01

    Full Text Available In the practical design of nuclear building structures subjected to an aircraft crash, the structures are required to prevent scabbing and perforation. NEI 07-13 provided the formulas to predict the minimum reinforced concrete (RC wall thickness to prevent the local damage caused by aircraft engine impact. However, these formulas may not be suitable for predicting the thickness of the ultra-high performance fiber reinforced concrete (UHPFRC wall. In this study, the local damage of a UHPFRC wall caused by the impact of aircraft engine missile is investigated using a finite element program LS-DYNA. The structural components of the UHPFRC panel, aircraft engine model, and their contacts are fully modeled. The analysis results are verified with the test results. A parametric study with varying panel thickness, fiber type and content, and impact velocity is performed to investigate the local damage of the UHPFRC panel. Based on a comparison with the given formulas, the modified equations of Chang and Degen are proposed to predict the minimum wall thickness to prevent scabbing and perforation in the case in which the UHPFRC structure is used.

  20. Impact of traffic states on freeway crash involvement rates.

    Science.gov (United States)

    Yeo, Hwasoo; Jang, Kitae; Skabardonis, Alexander; Kang, Seungmo

    2013-01-01

    Freeway traffic accidents are complicated events that are influenced by multiple factors including roadway geometry, drivers' behavior, traffic conditions and environmental factors. Among the various factors, crash occurrence on freeways is supposed to be strongly influenced by the traffic states representing driving situations that are changed by road geometry and cause the change of drivers' behavior. This paper proposes a methodology to investigate the relationship between traffic states and crash involvements on the freeway. First, we defined section-based traffic states: free flow (FF), back of queue (BQ), bottleneck front (BN) and congestion (CT) according to their distinctive patterns; and traffic states of each freeway section are determined based on actual measurements of traffic data from upstream and downstream ends of the section. Next, freeway crash data are integrated with the traffic states of a freeway section using upstream and downstream traffic measurements. As an illustrative study to show the applicability, we applied the proposed method on a 32-mile section of I-880 freeway. By integrating freeway crash occurrence and traffic data over a three-year period, we obtained the crash involvement rate for each traffic state. The results show that crash involvement rate in BN, BQ, and CT states are approximately 5 times higher than the one in FF. The proposed method shows promise to be used for various safety performance measurement including hot spot identification and prediction of the number of crash involvements on freeway sections. PMID:22795398

  1. Safety assessment of A92 reactor building for large commercial aircraft crash

    International Nuclear Information System (INIS)

    The current paper presents key elements of the comprehensive analyses of the effects due to a large aircraft collision with the reactor building of Belene NPP in Bulgaria. The reactor building is a VVER A92; it belongs to the third+ generation and includes structural measures for protection against an aircraft impact as standard design. The A92 reactor building implements a double shell concept and is composed of thick RC external walls and an external shell which surrounds an internal pre-stressed containment and the internal walls of the auxiliary building. The malevolent large aircraft impact is considered as a beyond design base accident (Design Extended Conditions, DEC). The main issues under consideration are the structural integrity, the equipment safety due to the induced vibrations, and the fire safety of the entire installation. Many impact scenarios are analyzed varying both impact locations and loading intensity. A large number of non-linear dynamic analyses are used for assessment of the structural response and capacity, including different type of structural models, different finite element codes, and different material laws. The corresponding impact loadings are represented by load time functions calculated according to three different approaches, i.e. loading determined by Riera's method (Riera, 1968), load time function calculated by finite element analysis (Henkel and Klein, 2007), and coupled dynamic analysis with dynamic interaction between target and projectile. Based on the numerical results and engineering assessments the capacity of the A92 reactor building to resist a malevolent impact of a large aircraft is evaluated. Significant efforts are spent on safety assessment of equipment by using an evaluation procedure based on damage indicating parameters. As a result of these analyses several design modifications of structure elements are performed. There are changes of the layout of reinforcement, special arrangements and spatial

  2. Experiments to validate the assumptions on Pu release in an aircraft crash

    International Nuclear Information System (INIS)

    An aeroplane crash on a Plutonium storing and processing fuel element factory induces by the impact on the ground and the combustion of the kerosene mechanical destruction and oxidation and as a consequence atomization of pellets. The mass distribution of such powders and powders which are stored in the factory, were determined. The release of these powders as well as from Pu-nitrate within the respirable fine dust range was studied during a kerosene fire inside a glove-box. At a sampling time of 4 minutes the release was found to be between 0.005% and 0.12% of the mass of the Pu-compounds, which were exposed to the fire. Experiments with CeO2 as a substitute for radioactive material for release and dispersion up to 1 km from the fire were carried out. Per kg material which is blown into the flame, a person in the lee-side of the fire could inhale 30 to 300 ng. (orig.)

  3. Dynamic response of nuclear power plant due to earthquake ground motion and aircraft impact

    International Nuclear Information System (INIS)

    This paper examines both the indirect effect of aircraft crash and the effect of earthquake ground motions on the dynamic response of a single reactor nuclear island. The effect of gound properties on the dynamic response is investigated by varying the ground stiffness and damping over a range defined by the shear wave velocities 500 to 2000 m/sec. The effect of both the aircraft crash and the earthquake on the reactor plant can be compared directly by computing floor response spectra from the time-history response. The precise shape of the forcing function does significantly affect the response and consequently the floor response spectra. Peak floor response accelerations vary by up to 40% in the case of the MRCA and the effect of a variance on the prescribed aircraft impact forcing function should always be considered. However it is concluded that where nuclear facilities are being designed to ensure a safe shutdown against earthquakes, then provided the primary containment is designed to protect the primary reactor circuit against direct damage from a Multi Role Combat aircraft the reactor plant within the primary containment will have an acceptable response. In the event of a large aircraft such as the Boeing 707 crashing onto the facility, then the design of the reactor plant could be affected depending upon the amount of energy absorbed locally through direct damage

  4. Large Field Photogrammetry Techniques in Aircraft and Spacecraft Impact Testing

    Science.gov (United States)

    Littell, Justin D.

    2010-01-01

    The Landing and Impact Research Facility (LandIR) at NASA Langley Research Center is a 240 ft. high A-frame structure which is used for full-scale crash testing of aircraft and rotorcraft vehicles. Because the LandIR provides a unique capability to introduce impact velocities in the forward and vertical directions, it is also serving as the facility for landing tests on full-scale and sub-scale Orion spacecraft mass simulators. Recently, a three-dimensional photogrammetry system was acquired to assist with the gathering of vehicle flight data before, throughout and after the impact. This data provides the basis for the post-test analysis and data reduction. Experimental setups for pendulum swing tests on vehicles having both forward and vertical velocities can extend to 50 x 50 x 50 foot cubes, while weather, vehicle geometry, and other constraints make each experimental setup unique to each test. This paper will discuss the specific calibration techniques for large fields of views, camera and lens selection, data processing, as well as best practice techniques learned from using the large field of view photogrammetry on a multitude of crash and landing test scenarios unique to the LandIR.

  5. Modular HTR confinement/containment and the protection against aircraft crash

    International Nuclear Information System (INIS)

    Does an HTR need a containment - pressure resistant - or is it possible - licensable - to have only a so-called confinement. The answer depends on both the results of the safety analysis of the accidents considered in the design and the acceptance by the licensing authorities and the public of a safety approach only based on severe core damage exclusion. The safety approach to be developed for modular HTRs must describe the application of the defence in depth principle for such reactors. Whatever the requirements on the last confinement barrier could be, a convincing demonstration of the exclusion of any severe core damage is needed, relying on exhaustive and bounding considerations of severe core damage initiators and the use of non-questionable arguments. The paper presents the containment issues for HTRs based on German experience background and considerations for modern modular HTR safety approach including beyond design situations: - For the German HTRs (designed in the 80s), it could be shown in the licensing procedures in Germany that there was no need for a pressure retaining and gas tight containment to enclose radioactive nuclides released from the nuclear heat source. Instead, the confinement envelope acted in conjunction with other barriers to minimize the release of radioactive nuclides and the radiological impact on the environment. - The confinement envelope consisted of the reactor building, a sub-atmospheric pressure system, a building pressure relief system, an HVAC systems isolation and a filtration system. - During a major depressurization accident, unfiltered releases were discharged to the environment. The analyses results show that the environmental impact was far below the dose limits according to the German Radiological Protection Ordinance, even when the effect of filters was not taken into account. - The demonstration strongly relied on the assumptions made for the source term definition, e.g. the fuel particles failure rates (under

  6. Side Impact Regulatory Trends, Crash Environment and Injury Risk in the USA.

    Science.gov (United States)

    Prasad, Priya; Dalmotas, Dainius; Chouinard, Aline

    2015-11-01

    Light duty vehicles in the US are designed to meet and exceed regulatory standards, self-imposed industry agreements and safety rating tests conducted by NHTSA and IIHS. The evolution of side impact regulation in the US from 1973 to 2015 is discussed in the paper along with two key industry agreements in 2003 affecting design of restraint systems and structures for side impact protection. A combination of all the above influences shows that vehicles in the US are being designed to more demanding and comprehensive requirements than in any other region of the world. The crash environment in the US related to side impacts was defined based on data in the nationally representative crash database NASS. Crash environment factors, including the distribution of cars, light trucks and vans (LTV's), and medium-to-heavy vehicles (MHV's) in the fleet, and the frequency of their interactions with one another in side impacts, were considered. Other factors like, crash severity in terms of closing velocity between two vehicles involved in crash, gender and age of involved drivers in two-vehicle and single vehicle crashes, were also examined. Injury risks in side impacts to drivers and passengers were determined in various circumstances such as near-side, far-side, and single vehicle crashes as a function of crash severity, in terms of estimated closing speed or lateral delta-V. Also injury risks in different pairs of striking and struck cars and LTV's, were estimated. A logistic regression model for studying injury risks in two vehicle crashes was developed. The risk factors included in the model include case and striking vehicles, consisting of cars, SUV's, vans, and pickup trucks, delta-V, damage extent, occupant proximity to the impact side, age and gender of the occupant, and belt use. Results show that car occupants make up the vast majority of serious-to-fatally injured occupants. Injury rates of car occupants in two-vehicle collision are highest when the car is struck by a

  7. Occupant injury in rollover crashes - Contribution of planar impacts with objects and other vehicles.

    Science.gov (United States)

    Ivarsson, Johan; Poplin, Gerald; McMurry, Tim; Crandall, Jeff; Kerrigan, Jason

    2015-12-01

    Planar impacts with objects and other vehicles may increase the risk and severity of injury in rollover crashes. The current study compares the frequency of injury measures (MAIS 2+, 3+, and 4+; fatal; AIS 2+ head and cervical spine; and AIS 3+ head and thorax) as well as vehicle type distribution (passenger car, SUV, van, and light truck), crash kinematics, and occupant demographics between single vehicle single event rollovers (SV Pure) and multiple event rollovers to determine which types of multiple event rollovers can be pooled with SV Pure to study rollover induced occupant injury. Four different types of multiple event rollovers were defined: single and multi-vehicle crashes for which the rollover is the most severe event (SV Prim and MV Prim) and single and multi-vehicle crashes for which the rollover is not the most severe event (SV Non-Prim and MV Non-Prim). Information from real world crashes was obtained from the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) for the period from 1995 through 2011. Belted, contained or partially ejected, adult occupants in vehicles that completed 1-16 lateral quarter turns were assigned to one of the five rollover categories. The results showed that the frequency of injury in non-primary rollovers (SV Non-Prim and MV Non-Prim) involving no more than one roof inversion is substantially greater than in SV Pure, but that this disparity diminishes for crashes involving multiple inversions. It can further be concluded that for a given number of roof inversions, the distribution of injuries and crash characteristics in SV Pure and SV Prim crashes are sufficiently similar for these categories to be considered collectively for purposes of understanding etiologies and developing strategies for prevention. PMID:26418467

  8. AP1000R design robustness against extreme external events - Seismic, flooding, and aircraft crash

    International Nuclear Information System (INIS)

    Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000R nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel containment vessel which is

  9. Analysis of impact of large commercial aircraft on a prestressed containment building

    International Nuclear Information System (INIS)

    Highlights: • Aircraft impact analyses are performed using the missile–target interaction method. • A large commercial B747 aircraft is considered with erosion effect. • The rigid wall impact test shows the validity of the developed aircraft model. • The parametric studies on the fictitious containment building are performed. • The plastic failure of the target is governed by the impulse of aircraft at the first momentum peak. - Abstract: In this paper, the results of nonlinear dynamic analyses of a concrete containment building under extreme loads are presented. The impact of a large commercial B747 airliner is investigated as the extreme load, and a rigid wall impact test is performed using commercial nonlinear finite element codes. The impact forces exerted by the aircraft are verified compared with the time-dependent impact force provided by OECD/NEA (2002), which was calculated based on the so-called Riera method. The rigid wall impact analysis shows that the finite element model of a B747 is appropriate for the purpose of the aircraft crash analysis exposed to the external hazard of “Beyond Design-Basis Events” defined by U.S. Nuclear Regulatory Commission. Finally, the applicability of this methodology is further studied and verified by conducting parametric studies on the critical infrastructures of nuclear power plant containment structures

  10. Assessment of aircraft impact loads on the design of ITER buildings

    International Nuclear Information System (INIS)

    The design of ITER buildings and main mechanical components must consider the effect of a variety of external hazards, being aircraft impact among them. Therefore, it is the objective of the work presented in this paper to perform a first assessment on the subject. The methodology proposed by ITER to assess the effect of aircraft impact on the design of the Tokamak Complex is inspired by ETCC, which was developed for the European Pressurized Reactor. Thus, its applicability to ITER experimental nuclear facilities may raise some specific problems, since the consequences of the methodology and model proposed for aircraft impacts are not very well known. The work presented in this paper aims to assess the applicability of the dynamic simplified model proposed by ITER and perform a first check of the basic design of the aircraft crash protection concrete structure of the Tokamak Complex. The analysis is based on the simplified methodology, and is limited to a limited number of configurations. Moreover, in order to provide a guide for definition of the final geometry, the material choices of concrete structures, and the steel reinforcement ratios of the aircraft crash protection structures, an optimization analyses has been performed. It is important to note that, since the Tokamak Complex is seismically isolated in the horizontal plane, the floor response spectra (FRS) caused by an aircraft impact could be more important than those induced by seismic action. Therefore, in order to make a preliminary assessment on this issue, the FRS caused by an aircraft impact in some representative scenarios has been generated.

  11. Influence of aircraft impact on seismic isolated SMR reactor

    International Nuclear Information System (INIS)

    In the past decades a lot of effort has been done to increase the reliability of NPP, particularly against the earthquakes effects, adopting the highly attractive strategy of the seismic isolation. Isolator bearings seem able to increase the safety margin/integrity of the safety relevant nuclear structures and to enable the standardization of the reactor design to be deployed across a wider range of sites. However in principle the design of a nuclear power plant depends on the safety aspects related also to other type of external events, like the aircraft impact that was/is of relevant importance for NPP safety (especially after the Sept. 2001) and must be considered in the design of both Generation III+ and IV reactors. This paper is related to a preliminary study of the global response of a seismically isolated reactor building subjected to a vicious commercial aircraft impact. In this framework the effects of impulsive loading due to the progressive aircraft crashing were evaluated, considering the potential for structural failure of the external building walls due to shearing and bending dynamic loads, with reference to the effects of the structure perforation, including concrete spalling of the internal surfaces and propagation of dynamic waves that could affect NPP safety systems and structures. To the purpose a rather refined numerical methodology was employed; three-dimensional models (FEM approach) of a reference SMR reactor containment and possible realistic aircraft structures were set up and used in the performed analyses, taking also into account suitable materials behaviour and constitutive laws. The structural analysis of the reference NPP internal components was carried out to appropriately check mainly the containment strength margin in the case of the considered accident and test the chosen models and numerical calculation approach. (author)

  12. Fuel dispersal modeling for aircraft-runway impact scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Tieszen, S.R.

    1995-11-01

    A fuel dispersal model for C-141 transport accidents was developed for the Defense Nuclear Agency`s Fuel Fire Technology Base Program to support Weapon System Safety Assessments. The spectrum of accidents resulting from aircraft impact on a runway was divided into three fuel dispersal regimes: low, intermediate, and high-velocity impact. Sufficient data existed in the accident, crash test, and fuel-filled bomb literature to support development of a qualitative framework for dispersal models, but not quantitative models for all regimes. Therefore, a test series at intermediate scale was conducted to generate data on which to base the model for the high-velocity regime. Tests were conducted over an impact velocity range from 12 m/s to 91 m/s and angles of impact from 22.5{degrees} to 67.5{degrees}. Dependent variables were area covered by dispersed fuel, amount of mass in that area, and location of the area relative to the impact line. Test results showed that no liquid pooling occurred for impact velocities greater than 61 m/s, independent of the angle of impact. Some pooling did occur at lower velocities, but in no test was the liquid-layer thickness greater than 5.25 mm.

  13. Development of Probabilistic Risk Assessment Procedure of Nuclear Power Plant under Aircraft Impact Loadings

    Energy Technology Data Exchange (ETDEWEB)

    Hahm, Daegi; Shin, Sangshup; Park, Jin Hee; Choi, Inkil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this paper, the total technical roadmap and the procedure to assess the aircraft impact risk will be introduced. In the first year of the research project, 2012, we developed aircraft impact accident scenario and performed preliminary fragility analysis of the local failure of the targeted wall by aircraft impact. An aircraft impact event can be characterized by the appropriate load parameters (i. e., aircraft type, mass, velocity, angle of crash, etc.). Therefore, the reference parameter should be selected to represent each load effect in order to evaluate the capacity/fragility of SSCs using deterministic or probabilistic methods. This is similar to the use of the peak ground acceleration (PGA) to represent the ground motion spectrum of the earthquake in the seismic probabilistic risk assessment (SPRA) approach. We developed the methodology to decide on the reference parameter for the aircraft impact risk quantification among some reasonable candidates, which can represent many uncertain loading parameters. To detect the response and the damage of the target structure, missile-target interaction method and Riera's time-history analysis method have been used primarily in the aircraft impact research area. To define the reference loading parameter, we need to perform repetitive simulations for many analysis cases. Thus, we applied a revised version of Riera's method, which is appropriate for a simplified impact simulation. The target NPP to determine the reference parameter and evaluate the preliminary assessment of aircraft impact risk was selected among the typical Korean PWR NPPs. The response has been calculated for pre-stressed concrete containment buildings subjected to aircraft impact loading, and the responses according to each reference parameter have been analyzed. Recently, we also evaluated the floor response spectra for the locations of important components for the estimation of the failure probabilities and fragility functions of

  14. Development of Probabilistic Risk Assessment Procedure of Nuclear Power Plant under Aircraft Impact Loadings

    International Nuclear Information System (INIS)

    In this paper, the total technical roadmap and the procedure to assess the aircraft impact risk will be introduced. In the first year of the research project, 2012, we developed aircraft impact accident scenario and performed preliminary fragility analysis of the local failure of the targeted wall by aircraft impact. An aircraft impact event can be characterized by the appropriate load parameters (i. e., aircraft type, mass, velocity, angle of crash, etc.). Therefore, the reference parameter should be selected to represent each load effect in order to evaluate the capacity/fragility of SSCs using deterministic or probabilistic methods. This is similar to the use of the peak ground acceleration (PGA) to represent the ground motion spectrum of the earthquake in the seismic probabilistic risk assessment (SPRA) approach. We developed the methodology to decide on the reference parameter for the aircraft impact risk quantification among some reasonable candidates, which can represent many uncertain loading parameters. To detect the response and the damage of the target structure, missile-target interaction method and Riera's time-history analysis method have been used primarily in the aircraft impact research area. To define the reference loading parameter, we need to perform repetitive simulations for many analysis cases. Thus, we applied a revised version of Riera's method, which is appropriate for a simplified impact simulation. The target NPP to determine the reference parameter and evaluate the preliminary assessment of aircraft impact risk was selected among the typical Korean PWR NPPs. The response has been calculated for pre-stressed concrete containment buildings subjected to aircraft impact loading, and the responses according to each reference parameter have been analyzed. Recently, we also evaluated the floor response spectra for the locations of important components for the estimation of the failure probabilities and fragility functions of

  15. Demographics, Velocity Distributions, and Impact Type as Predictors of AIS 4+ Head Injuries in Motor Vehicle Crashes

    OpenAIRE

    Yoganandan, Narayan; Fitzharris, Michael; Pintar, Frank A.; Stemper, Brian D.; Rinaldi, James; Maiman, Dennis J.; Fildes, Brian N.

    2011-01-01

    The objective of the study was to determine differences between the United States-based NASS and CIREN and Australia-based ANCIS databases in occupant-, crash-, and vehicle-related parameters for AIS 4+ head injuries in motor vehicle crashes. Logistic regression analysis was performed to examine roles of the change in velocity (DV), crash type (frontal, far-side, nearside, rear impact), seatbelt use, and occupant position, gender, age, stature, and body mass in cranial traumas. Belted and unb...

  16. Effect of forming rate on the impact tensile properties of the steels under crash test

    Directory of Open Access Journals (Sweden)

    M. Grumbach

    2007-01-01

    Full Text Available Purpose: The main objective of this study is to examine the mechanical and metallurgical behaviour of thetailored blanks and base metals for thin sheet steels used in the car industry by using a new type of crash test/impact (ITT. It exposes the effect of forming rate on the toughness of thin welded joints (tailored blanks forInterstitial Free (IFS steels used in the automotive industry.Design/methodology/approach: A special crash test device is used in different temperature and the simulatedcrash tests are performed at a constant speed of 5.52 m/s (strain rate about 250 s−1.Findings: The specimen is submitted to impact tensile test at different temperatures. According to testingtemperature, fracture mode varies: At low temperatures, brittle fracture occurs: Due to stress concentration,fracture always occurs in the notched section. At high temperatures, the specimen fails by ductile fracture.Toughness of the steel sheets (base metals, BM or tailored blanks, TBs after forming at certain levels is wellcompared at different materials and test conditions.Practical implications: This study gives very useful data for the crash test. This is a new conception ofspecimen and of the impact/crash machine. It is easily used in automotive industry for practical and economicreason to give rapid answers to designer and also steel makers for ranking the materials.Originality/value: This research used a new developed test called simplified crash test for evaluating theeffect of forming rate on the toughness of thin welded joints (tailored blanks / mechanical assemblies in highformability steel sheets for stamping submitted to dynamic loads such as experienced in real crash tests.

  17. Effect of forming rate on the impact tensile properties of the steels under crash test

    OpenAIRE

    Grumbach, M; Bayraktar, E.; Kaplan, D.(Department of Physics, Illinois Institute of Technology, Chicago, Illinois, 60616, U.S.A.)

    2007-01-01

    Purpose: The main objective of this study is to examine the mechanical and metallurgical behaviour of thetailored blanks and base metals for thin sheet steels used in the car industry by using a new type of crash test/impact (ITT). It exposes the effect of forming rate on the toughness of thin welded joints (tailored blanks) forInterstitial Free (IFS) steels used in the automotive industry.Design/methodology/approach: A special crash test device is used in different temperature and the simula...

  18. Robust human body model injury prediction in simulated side impact crashes.

    Science.gov (United States)

    Golman, Adam J; Danelson, Kerry A; Stitzel, Joel D

    2016-01-01

    This study developed a parametric methodology to robustly predict occupant injuries sustained in real-world crashes using a finite element (FE) human body model (HBM). One hundred and twenty near-side impact motor vehicle crashes were simulated over a range of parameters using a Toyota RAV4 (bullet vehicle), Ford Taurus (struck vehicle) FE models and a validated human body model (HBM) Total HUman Model for Safety (THUMS). Three bullet vehicle crash parameters (speed, location and angle) and two occupant parameters (seat position and age) were varied using a Latin hypercube design of Experiments. Four injury metrics (head injury criterion, half deflection, thoracic trauma index and pelvic force) were used to calculate injury risk. Rib fracture prediction and lung strain metrics were also analysed. As hypothesized, bullet speed had the greatest effect on each injury measure. Injury risk was reduced when bullet location was further from the B-pillar or when the bullet angle was more oblique. Age had strong correlation to rib fractures frequency and lung strain severity. The injuries from a real-world crash were predicted using two different methods by (1) subsampling the injury predictors from the 12 best crush profile matching simulations and (2) using regression models. Both injury prediction methods successfully predicted the case occupant's low risk for pelvic injury, high risk for thoracic injury, rib fractures and high lung strains with tight confidence intervals. This parametric methodology was successfully used to explore crash parameter interactions and to robustly predict real-world injuries. PMID:26158552

  19. Development of Aircraft Impact Scenario on a Concrete Cask in Interim Storage Facility

    International Nuclear Information System (INIS)

    This paper provides a method for determining the failure criteria in global and local damage responses for the concrete cask under extreme mechanical impact condition. IAEA safety guide No. SSG-15 mentions the hypothetical initiating events of SNF storage. Among the external initiating events, the aircraft strike on a storage cask is considered one of the dominant contributions to the risk during storage phase. Although the probability of aircraft crash on ISF is extremely small, it is important to develop the accident scenario caused by an intentional malicious acts launched towards the storage facility in terms to improve inherent security. Thus, the probabilistic approach to develop aircraft impact scenarios on a storage cask is needed

  20. Aircraft impact analysis for the HFBR

    International Nuclear Information System (INIS)

    This report presents an analysis performed to determine the annual frequency at which aircraft are expected to strike the High Flux Beam Reactor (HFBR) complex, located at Brookhaven National Laboratory. Since the HFBR is not hardened against light aircraft, this report considers the impact of military, commercial, twin engine and single engine aircraft operating in the vicinity of the HFBR. The large volume of light aircraft operating in this area contributes heavily to the estimated annual impact frequency of 3.54E-05 impacts per year. There are two chapters and seven appendices in this report. The first chapter describes the airspace in the vicinity of the HFBR. This includes five airports, two major airways, one standard arrival route, as well as a significant volume of radar vectored and air-taxi traffic. The second chapter of this report presents the calculations by which the expected impact frequency was derived, and an assessment of the uncertainty in those calculations. The calculations were performed using the method outlined in the NRC Standard Review Plan. A separate set of calculations is presented for each of three sources of aircraft: airway traffic, Brookhaven Airport, and Calverton Airport. The appendices contain discussions and side calculations ancillary to the presentation in the second section. This includes a discussion of the data used to estimate traffic counts, information on accident rates, and several other points which would have only been distracting if included in the main discussion

  1. Dynamics and Biases of Online Attention: The Case of Aircraft Crashes

    CERN Document Server

    García-Gavilanes, Ruth; Yasseri, Taha

    2016-01-01

    Researchers have used Wikipedia data as a source to quantify attention on the web. One way to do it is by analysing the editorial activities and visitors' views of a set of Wikipedia articles. In this paper, we particularly study attention to aircraft incidents and accidents using Wikipedia in two different language editions, English and Spanish. We analyse how attention varies over several dimensions such as number of deaths, airline region, locale, date, first edit, etc. Several patterns emerge with regard to these dimensions and articles. For example, we find evidence that the attention given by Wikipedia editors to pre-Wikipedia aircraft incidents and accidents depends on the region of the airline for both English and Spanish editions. For instance, North American airline companies receive more prompt coverage in English Wikipedia. We also observe that the attention given by Wikipedia visitors is influenced by the airline region but only for events with high number of deaths. Finally we show that the rate...

  2. Experiments to validate the assumptions on Pu release in an aircraft crash

    International Nuclear Information System (INIS)

    This report describes simulation experiments with the substitute powder CeO2 to study the release and dispersion of PuO2-powder induced by kerosene fires after an aeroplane crash on a Plutonium processing fuel element plant. The release rates of CeO2-powder were found to be a nonlinear function of te kerosene combustion rate. The release rates during a ''micro-scale'' fire inside the glovebox (pool area some 20 cm2) were characterized by values of less than 10 μg/s, those during a conflagration (pool area some 200 m2) by values of somewhat more than 25 mg/s. Because of the lack of other weather conditions the dispersion experiments were exclusively realized during weak to moderate winds. Small scale fire induced maximum inhalation hazards from PuO2-powder used in production essentially exceeded those of large scale conflagrations. Obviously the activity intake by inhalation exceeded to some extent the admissable threshold of the annual activity intake. (orig.)

  3. Impact of aircraft systems within aircraft operation: A MEA trajectory optimisation study

    OpenAIRE

    Seresinhe, R.

    2014-01-01

    Air transport has been a key component of the socio-economic globalisation. The ever increasing demand for air travel and air transport is a testament to the success of the aircraft. But this growing demand presents many challenges. One of which is the environmental impact due to aviation. The scope of the environmental impact of aircraft can be discussed from many viewpoints. This research focuses on the environmental impact due to aircraft operation. Aircraft operation causes...

  4. Injury Risk Functions in Frontal Impacts Using Data from Crash Pulse Recorders

    OpenAIRE

    Stigson, Helena; Kullgren, Anders; Rosén, Erik

    2012-01-01

    Knowledge of how crash severity influences injury risk in car crashes is essential in order to create a safe road transport system. Analyses of real-world crashes increase the ability to obtain such knowledge.

  5. On the response of a reactor building and its equipment to aircraft crash

    International Nuclear Information System (INIS)

    The present study investigates the dynamic response of the ASEA-ATOM BWR 75 reactor building in terms of response spectra at significant locations considering various aircraft and points of load application. In the first part of the study a total of 21 forcing functions, most of them from the open literature and including the commonly used standard functions, have been studied with respect to documentation, consistency and frequency content. Since none of the forcing functions have been experimentally verified, their validity must be assessed mainly by judging the structural models and assumptions used in their derivation and by checking their consistency. In the second part, linear dynamical models of various degrees of detailedness have been investigated regarding their capacity to describe the behavior of the reactor building under this high frequency loading. The most detailed model consists of plane stress finite elements for every significant wall and floor. In the third part of the study the effects of a number of parameters on the response of the building are investigated. The parameters include the points of attack, damping values, soil spring stiffness as well as different forcing functions of various frequency contents. The reponse is displayed as response spectra and member forces for characteristic locations. The results serve as a basis for development of standardized design floor response spectra and for the structural verification of the bui

  6. Structural design for aircraft impact loading

    International Nuclear Information System (INIS)

    The distribution of military aircraft and proximity to commercial air routes requires the analysis of aircraft impact effect on nuclear power plant facilities in Europe. The 'hardened-building' approach has led to the consideration of severe shock and vibration caused by the aircraft impact and development of corresponding floor response spectra for component design. The reactor auxiliary system building allows a more defensive alternate in the form of a partially softened design. In this approach the equipment layout is arranged such that equipment performing either safety functions or having the potential for significant release of radioctivity (upon destruction) is located in the central area of the plant and is enclosed in thick concrete walls for shielding and protection purposes. The non-safety class equipment is arranged in the area peripheral to the hardened central area and enclosed in thin concrete walls. Since the kinetic energy of the impacting aircraft is absorbed by the collapsed thin walls and ceilings, the vibrational effect on the safety class equipment is drastically reduced. In order to achieve the objective of absorbing high kinetic energy and yet reduce the shock and vibration effects, the softened exterior walls require low resistance and high ductility. In order not to increase the construction cost, and yet to assure the safety of the plant, some dynamic tests of conventionally reinforced slabs have to be performed all the way to collapse. These calculations have assumptions of achieving the maximum velocity instantaneously after impact, and take into account the kinetic energy in the broken wall. Nonlinear equations of motion are also formulated and solved. The results indicate that the phantom jet would go through the first wall. The second wall would stop the jet, but would sustain some permanent deformation and damage

  7. Investigation on impact resistance of steel plate reinforced concrete barriers against aircraft impact. Pt.1: Test program and results

    International Nuclear Information System (INIS)

    Steel plate reinforced concrete (SC) structures composed of concrete and steel plates with headed studs are considered to be more effective than RC structures against aircraft impact. This is due to the effects of the steel plates, especially the rear-face steel plates. Thus, their application to outer walls and roofs of risk-sensitive structures such as nuclear-related structures is expected to mitigate damage to critical components. However, few data have been available to understand and evaluate the complex behavior and damage process of SC panels against an aircraft impact. The objective of this study was to obtain valuable experimental and analytical data essential to investigate and establish a protection design method for SC structures against an aircraft impact. As a first step, impact tests using 1/7.5-scale models were carried out to clarify the damage phenomena caused by an aircraft crash into steel plate reinforced concrete (SC) panels. The results indicated that the steel plate, especially the rear-face plate, has a significant effect in preventing scattering of scabbed concrete debris. It was confirmed that SC panels have much better impact resistant performance than conventional reinforced concrete panels, enabling the thickness of protection panels to be reduced by approximately 30%. (authors)

  8. A Comparison of Force-Time History Analysis Methods for Simplified Aircraft Impact Simulation

    International Nuclear Information System (INIS)

    In this paper, by comparing the various F-T History analysis method, we are about to propose the most reliable simplified method under the same condition with M-T Interaction analysis method. To find the suitable loading area applied aircraft crash, the studies for a various loading area (Case 1, 2, 3) ware performed using F-T History analysis method, and the former results were compared to the result of Case 4 using M-T Interaction analysis method. The various results according to the proposed loading area were pointed out. Thus, the results for a simplified loading area applied impact load may be fairly sensitive to the assumption associated with loading area. Finally, we can conclude that the Case 3 shows conservative and the most similar results with realistic simulation using M-T Interaction analysis method, i. e., Case 4. The reaction force-time relationship for accidental strike of Boeing 707-320 aircraft against a rigid surface was proposed by Riera. After that, the aircraft impact analysis has been studied significantly in the last few decades. The only way to acquire an exact solution of the aircraft impact analysis is direct impact test. However, for the large commercial aircraft impact, this direct test has been hardly performed because the scale of aircraft and impacted wall is very huge. Up to date, the numerical simulation using Missile-Target (M-T) Interaction analysis method is known as the only way to obtain a relatively accurate solution. However, because of its massive computational efforts and modeling complexity, this method is inadequate and inefficient to the application of the fragility analysis and risk assessments which is required many times of iterative simulations. Thus, a more simplified and conservative analysis method is required. The simplified method such as Force-Time (F-T) History analysis method has been studied by Riera, Sugano et al., Mullapudi et al. and etc.

  9. Safety impacts of platform tram stops on pedestrians in mixed traffic operation: A comparison group before-after crash study.

    Science.gov (United States)

    Naznin, Farhana; Currie, Graham; Logan, David; Sarvi, Majid

    2016-01-01

    Tram stops in mixed traffic environments present a variety of safety, accessibility and transport efficiency challenges. In Melbourne, Australia the hundred year-old electric tram system is progressively being modernized to improve passenger accessibility. Platform stops, incorporating raised platforms for level entry into low floor trams, are being retro-fitted system-wide to replace older design stops. The aim of this study was to investigate the safety impacts of platform stops over older design stops (i.e. Melbourne safety zone tram stops) on pedestrians in the context of mixed traffic tram operation in Melbourne, using an advanced before-after crash analysis approach, the comparison group (CG) method. The CG method evaluates safety impacts by taking into account the general trends in safety and the unobserved factors at treatment and comparison sites that can alter the outcomes of a simple before-after analysis. The results showed that pedestrian-involved all injury crashes reduced by 43% after platform stop installation. This paper also explores a concern that the conventional CG method might underestimate safety impacts as a result of large differences in passenger stop use between treatment and comparison sites, suggesting differences in crash risk exposure. To adjust for this, a modified analysis explored crash rates (crash counts per 10,000 stop passengers) for each site. The adjusted results suggested greater reductions in pedestrian-involved crashes after platform stop installation: an 81% reduction in pedestrian-involved all injury crashes and 86% reduction in pedestrian-involved FSI crashes, both are significant at the 95% level. Overall, the results suggest that platform stops have considerable safety benefits for pedestrians. Implications for policy and areas for future research are explored. PMID:26476596

  10. Climatic impact of aircraft induced ozone changes

    Energy Technology Data Exchange (ETDEWEB)

    Sausen, R.; Feneberg, B.; Ponater, M. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    The effect of aircraft induced ozone changes on the global climate is studied by means of the general circulation model ECHAM4. The zonal mean temperature signal is considered. In order to estimate the statistical significance of the climatic impact a multivariate statistical test hierarchy combined with the fingerprint method has been applied. Sensitivity experiments show a significant coherent temperature response pattern in the northern extra-tropics for mid-latitude summer conditions. It consists of a tropospheric warming of about 0.2 K with a corresponding stratospheric cooling of the same magnitude. (author) 16 refs.

  11. Overall impact of speed-related initiatives and factors on crash outcomes.

    Science.gov (United States)

    D'Elia, A; Newstead, S; Cameron, M

    2007-01-01

    From December 2000 until July 2002 a package of speed-related initiatives and factors took place in Victoria, Australia. The broad aim of this study was to evaluate the overall impact of the package on crash outcomes. Monthly crash counts and injury severity proportions were assessed using Poisson and logistic regression models respectively. The model measured the overall effect of the package after adjusting as far as possible for non-speed road safety initiatives and socio-economic factors. The speed-related package was associated with statistically significant estimated reductions in casualty crashes and suggested reductions in injury severity with trends towards increased reductions over time. From December 2000 until July 2002, three new speed enforcement initiatives were implemented in Victoria, Australia. These initiatives were introduced in stages and involved the following key components: More covert operations of mobile speed cameras, including flash-less operations; 50% increase in speed camera operating hours; and lowering of cameras' speed detection threshold. In addition, during the period 2001 to 2002, the 50 km/h General Urban Speed Limit (GUSL) was introduced (January 2001), there was an increase in speed-related advertising including the "Wipe Off 5" campaign, media announcements were made related to the above enforcement initiatives and there was a speeding penalty restructure. The above elements combine to make up a package of speed-related initiatives and factors. The package represents a broad, long term program by Victorian government agencies to reduce speed based on three linked strategies: more intensive Police enforcement of speed limits to deter potential offenders, i.e. the three new speed enforcement initiatives just described - supported by higher penalties; a reduction in the speed limit on local streets throughout Victoria from 60 km/h to 50 km/h; and provision of information using the mass media (television, radio and billboard) to

  12. Heterogeneous impacts of gender-interpreted contributing factors on driver injury severities in single-vehicle rollover crashes.

    Science.gov (United States)

    Wu, Qiong; Zhang, Guohui; Chen, Cong; Tarefder, Rafiqul; Wang, Haizhong; Wei, Heng

    2016-09-01

    In this study, a mixed logit model is developed to identify the heterogeneous impacts of gender-interpreted contributing factors on driver injury severities in single-vehicle rollover crashes. The random parameter of the variables in the mixed logit model, the heterogeneous mean, is elaborated by driver gender-based linear regression models. The model is estimated using crash data in New Mexico from 2010 to 2012. The percentage changes of factors' predicted probabilities are calculated in order to better understand the model specifications. Female drivers are found more likely to experience severe or fatal injuries in rollover crashes than male drivers. However, the probability of male drivers being severely injured is higher than female drivers when the road surface is unpaved. Two other factors with fixed parameters are also found to significantly increase driver injury severities, including Wet and Alcohol Influenced. This study provides a better understanding of contributing factors influencing driver injury severities in rollover crashes as well as their heterogeneous impacts in terms of driver gender. Those results are also helpful to develop appropriate countermeasures and policies to reduce driver injury severities in single-vehicle rollover crashes. PMID:27240126

  13. Modeling the behavior of wood during the crash of a cask impact limiter

    International Nuclear Information System (INIS)

    We present experimental results and their analytical modelling for wood under static and dynamic compression which involves large deformations. We also present a numerical constitutive relation for the compression of wood under large deformations. This 'wood model' is based on the experimental results mentioned before. It is used in a finite element explicit non-linear dynamic code. By this way, we can compare this model with other models used to characterize wood when it's used in cask impact limiters. Finally, we compare test results of a container model using wood as impact limiter crashed at 52 m/s with numerical results made with two numerical material types used to model the behaviour of wood under compression with large deformations (elastoplastic model and wood model). (authors)

  14. Assessment of aircraft impact possibilities at the Idaho Chemical Processing Plant on the INEL Site

    Energy Technology Data Exchange (ETDEWEB)

    Lee, L.G.; Mines, J.M.; Webb, B.B.

    1993-08-01

    The concern of this study was the possibility of an aircraft collision with facilities at the Idaho Chemical Processing Plant (ICPP). Two sets of data were combined in calculating the probability of this event. The first was from the Nuclear Regulatory Commission. The Nuclear Regulatory Commission data is used to check the adequacy of nuclear power plant location relative to aircraft crashes. For neighboring airport scenarios, the accepted rate unit is fatal crashes per square mile. For in-flight crash scenarios, a total loss of control crash rate (where the pilot was completely out of control) is used for evaluating nuclear reactors. Numbers were given per linear mile of flight. The other set of data was obtained from the National Transportation Safety Board`s annual review. These data points show higher crash frequencies because crashes in which the pilot maintained some control have not been excluded. By including this data set, the evaluation gained two advantages. First, the data are separated by type of aircraft, which makes frequencies for specific flight paths more meaningful. Second, the data are given year by year over a ten-year time span. Therefore, it is possible to gain a sense of the variability in crash frequencies from one year to another.

  15. Reducing the environmental impact of trials: a comparison of the carbon footprint of the CRASH-1 and CRASH-2 clinical trials

    Directory of Open Access Journals (Sweden)

    Roberts Ian

    2011-02-01

    Full Text Available Abstract Background All sectors of the economy, including the health research sector, must reduce their carbon emissions. The UK National Institute for Health Research has recently prepared guidelines on how to minimize the carbon footprint of research. We compare the carbon emissions from two international clinical trials in order to identify where emissions reductions can be made. Methods We conducted a carbon audit of two clinical trials (the CRASH-1 and CRASH-2 trials, quantifying the carbon dioxide emissions produced over a one-year audit period. Carbon emissions arising from the coordination centre, freight delivery, trial-related travel and commuting were calculated and compared. Results The total emissions in carbon dioxide equivalents during the one-year audit period were 181.3 tonnes for CRASH-1 and 108.2 tonnes for CRASH-2. In total, CRASH-1 emitted 924.6 tonnes of carbon dioxide equivalents compared with 508.5 tonnes for CRASH-2. The CRASH-1 trial recruited 10,008 patients over 5.1 years, corresponding to 92 kg of carbon dioxide per randomized patient. The CRASH-2 trial recruited 20,211 patients over 4.7 years, corresponding to 25 kg of carbon dioxide per randomized patient. The largest contributor to emissions in CRASH-1 was freight delivery of trial materials (86.0 tonnes, 48% of total emissions, whereas the largest contributor in CRASH-2 was energy use by the trial coordination centre (54.6 tonnes, 30% of total emissions. Conclusions Faster patient recruitment in the CRASH-2 trial largely accounted for its greatly increased carbon efficiency in terms of emissions per randomized patient. Lighter trial materials and web-based data entry also contributed to the overall lower carbon emissions in CRASH-2 as compared to CRASH-1. Trial Registration Numbers CRASH-1: ISRCTN74459797 CRASH-2: ISRCTN86750102

  16. HUMAN FACTOR IMPACT IN MILITARY AIRCRAFT MAINTENANCE

    OpenAIRE

    MARINKOVIC SRBOLJUB J.; DRENOVAC ALEKSANDAR Z.

    2015-01-01

    Aircraft maintenance, as a specific field of military materiel maintenance, is characterized by high reliability standards, based on regulations and technical standards. A system approach to maintenance represents the key element of maintenance quality, while aircraft maintenance staff has a crucial influence on the final outcome of aircraft maintenance.

  17. Dynamic impact testing of hedgehog spines using a dual-arm crash pendulum.

    Science.gov (United States)

    Swift, Nathan B; Hsiung, Bor-Kai; Kennedy, Emily B; Tan, Kwek-Tze

    2016-08-01

    Hedgehog spines are a potential model for impact resistant structures and material. While previous studies have examined static mechanical properties of individual spines, actual collision tests on spines analogous to those observed in the wild have not previously been investigated. In this study, samples of roughly 130 keratin spines were mounted vertically in thin substrates to mimic the natural spine layout on hedgehogs. A weighted crash pendulum was employed to induce and measure the effects of repeated collisions against samples, with the aim to evaluate the influence of various parameters including humidity effect, impact energy, and substrate hardness. Results reveal that softer samples-due to humidity conditioning and/or substrate material used-exhibit greater durability over multiple impacts, while the more rigid samples exhibit greater energy absorption performance at the expense of durability. This trend is exaggerated during high-energy collisions. Comparison of the results to baseline tests with industry standard impact absorbing foam, wherein the spines exhibit similar energy absorption, verifies the dynamic impact absorption capabilities of hedgehog spines and their candidacy as a structural model for engineered impact technology. PMID:27082130

  18. The impact of transportation infrastructure on bicycling injuries and crashes: a review of the literature

    Directory of Open Access Journals (Sweden)

    Cripton Peter A

    2009-10-01

    Full Text Available Abstract Background Bicycling has the potential to improve fitness, diminish obesity, and reduce noise, air pollution, and greenhouse gases associated with travel. However, bicyclists incur a higher risk of injuries requiring hospitalization than motor vehicle occupants. Therefore, understanding ways of making bicycling safer and increasing rates of bicycling are important to improving population health. There is a growing body of research examining transportation infrastructure and the risk of injury to bicyclists. Methods We reviewed studies of the impact of transportation infrastructure on bicyclist safety. The results were tabulated within two categories of infrastructure, namely that at intersections (e.g. roundabouts, traffic lights or between intersections on "straightaways" (e.g. bike lanes or paths. To assess safety, studies examining the following outcomes were included: injuries; injury severity; and crashes (collisions and/or falls. Results The literature to date on transportation infrastructure and cyclist safety is limited by the incomplete range of facilities studied and difficulties in controlling for exposure to risk. However, evidence from the 23 papers reviewed (eight that examined intersections and 15 that examined straightaways suggests that infrastructure influences injury and crash risk. Intersection studies focused mainly on roundabouts. They found that multi-lane roundabouts can significantly increase risk to bicyclists unless a separated cycle track is included in the design. Studies of straightaways grouped facilities into few categories, such that facilities with potentially different risks may have been classified within a single category. Results to date suggest that sidewalks and multi-use trails pose the highest risk, major roads are more hazardous than minor roads, and the presence of bicycle facilities (e.g. on-road bike routes, on-road marked bike lanes, and off-road bike paths was associated with the lowest

  19. Assessment of aircraft impact probabilities at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    The purpose of this study is to evaluate the possibility of an aircraft crash into a facility at the Idaho Chemical Processing Plant (ICPP). The ICPP is part of the Idaho National Engineering Laboratory (INEL). Based on the data used in this study, an air crash into any single facility at the ICPP is incredible, An air crash into aggregate areas incorporating the following is extremely unlikely: (1) ICPP radiological materials storage facilities, (2) ICPP major processing facilities, and (3) the ICPP total surface area. The radiological materials storage facilities aggregate areas are areas of concern usually requiring safety analyses, According to Department of Energy guidance, if the probability of a radiological release event is determined to be incredible, no further review is required. No individual facility in this analysis has a crash potential large enough to be credible. Therefore, an aircraft crash scenario is not required in the safety analysis for a single facility, but should be discussed relative to the ICPP aggregate areas, The highest probability of concern in the study was for aircraft to crash into the aggregate area for radiological materials storage facilities at the ICPP during Federal Aviation Administration (FAA) test flights

  20. The Impact of Driver Inattention on Near-Crash/Crash Risk: An Analysis Using the 100-Car Naturalistic Driving Study Data

    OpenAIRE

    Klauer, Sheila G; Dingus, Thomas A.; Neale, Vicki L.; Sudweeks, Jeremy D.; Ramsey, D J

    2006-01-01

    The purpose of this report was to conduct in-depth analyses of driver inattention using the driving data collected in the 100-Car Naturalistic Driving Study. An additional database of baseline epochs was reduced from the raw data and used in conjunction with the crash and near-crash data identified as part of the original 100-Car Study to account for exposure and establish near-crash/crash risk. The analyses presented in this report are able to establish direct relationships between driving b...

  1. Structural integrity analysis of an Ignalina nuclear power plant building subjected to an airplane crash

    International Nuclear Information System (INIS)

    Recent terrorist attacks using commandeered commercial airliners on civil structures have raised the issue of the ability of nuclear power plants to survive the consequences of an airliner crash. The structural integrity analysis due to the effects of an aircraft crash on an Ignalina nuclear power plant (INPP) accident localization system (ALS) building is the subject of this paper. A combination of the finite element method and empirical relationships were used for the analysis. A global structural integrity analysis was performed for a portion of the ALS building using the dynamic loading from an aircraft crash impact model. The local effects caused by impact of the aircraft's engine on the building wall were evaluated independently by using an empirical formula. The results from the crash analysis of a twin engine commercial aircraft show that the impacted reinforced concrete wall of the ALS building will not have through-the-wall concrete failure, and the reinforcement will not fail. Strain-rate effects were found to delay the onset of cracking. Therefore, the structural integrity of the impacted wall of the INPP ALS building will be maintained during the crash event studied

  2. Preliminary evaluation of aircraft impact on a near term nuclear power plant

    International Nuclear Information System (INIS)

    Highlights: ► The effects of military/civilian airplanes crash in a NPP were evaluated. ► We adequately simulated the global response and safety margin of an SMR reactor. ► The analyses allowed to represent the progressive failure/damaging processes. ► The outer containment seemed to suffer some localized penetration and spalling. ► The results highlighted the plant integrity is ensured despite the impact damages. - Abstract: For the assessment of the safety and durability of a nuclear power plant (NPP), the containment building behaviour shall be evaluated, under various service and extreme conditions, both natural or produced by natural accident or vicious man activities, like September 2001 jet aircraft crashes. The aim of this paper is to preliminary evaluate the effects and consequences of the energy transmitted to the outer containment walls (according to the international safety and design code guidelines, as NRC or IAEA ones) due to a military or civil aircraft impact into a nuclear plant, considered as a ‘beyond design basis’ event. To perform reliable analysis of such a large-scale structure and determine the structural effects of the propagation of this types of impulsive loads (response of containment structure), a realistic but still feasible numerical model with suitable materials characteristics were used by means of which relevant physical phenomena are reflected. Moreover a sensitivity analysis has also been carried out considering the effects of different containment wall thickness and reinforced/prestressed concrete features. The obtained results were analysed to check the NPP containment strength margins.

  3. Bond graph modeling and simulation of impact dynamics of an automotive crash

    International Nuclear Information System (INIS)

    With increase in the speeds of automotives, safety has become more and more important aspect of designers to care for. Thus, it is necessary to design the automobile body structure keeping in view all the safety requirements. As a result of the above-mentioned facts, in the recent years, the designers in making automotives more safe, more collision resistant and crash worthy have focused increased attention on designing automotives, which provides greater protection for the drivers and the passengers in case of an accident. Before a new model is launched into the market, a complete collision analysis is carried out to check the damage reduction capabilities and impact protection of automotives in case of an accident. Research in the field of automotive collision and impact analysis is a continuing activity and dedicated groups of engineers are devoting their full time and efforts for this. In this research work, the main attention is focused to provide a detailed knowledge about automotive collision analysis. The objective of this research paper is to develop an understanding of the automotive collision response. For this, we have done a simulation experiment in which, on a railroad, a train car is separated from a train and is moving towards two stationary train cars. By using a bond graph model of the system its state-space equations are found. Then by using software, the simulation is carried out. The bond graph method is a graphical presentation of the power flow using bonds. (author)

  4. Safety impacts of SUVs, vans, and pickup trucks in two-vehicle crashes.

    Science.gov (United States)

    Toy, Edmond L; Hammitt, James K

    2003-08-01

    Policy makers, vehicle manufacturers, and consumers have shown growing concern about the relative safety of sport utility vehicles (SUVs), vans, pickups, and cars. Empirical analysis of real-world crashes is complicated by the possibility that apparent relationships between vehicle type and safety may be confounded by other factors, such as driver behavior and crash circumstances. This study compares different vehicle types with respect to their crashworthiness (self-protection) and aggressivity (risk to others) in crashes between two passenger vehicles. The U.S. Crashworthiness Data System is used to analyze detailed information on 6,481 drivers involved in crashes during 1993-1999. Logistic regression analysis is used to model the risk of serious injury or death to a driver, conditional on a crash occurring. Covariates include the body type of each vehicle in the crash; the driver's age, gender, and restraint use; and the configuration of the crash. A unique feature of this study is the use of "delta-v" to represent the joint effects of vehicle mass and crash severity. While estimated effects are somewhat sensitive to the injury severity level used as the outcome variable, SUVs, vans, and pickups appear to be more aggressive and may be more crashworthy than cars. Effects of pickups are most pronounced. Drivers in pickups face less risk of serious injury than car drivers (odds ratio [OR], 0.35; 95% confidence interval [CI], 0.20-0.60), and drivers who collide with pickups experience more than twice the risk than those who collide with a car (OR, 2.18; 95% CI, 1.03-4.62). While vehicle mass and crash severity contribute to the apparent crashworthiness and aggressivity of passenger vehicles, other vehicle characteristics associated with body type (e.g., the stiffness and height of the underlying structure of the vehicle) also influence safety risks. PMID:12926558

  5. The application of EOQ and lead time crashing cost models in material with limited life time (Case study: CN-235 Aircraft at PT Dirgantara Indonesia)

    Science.gov (United States)

    Agustina Hidayat, Yosi; Ria Kasanah, Aprilia; Yudhistira, Titah

    2016-02-01

    PT. Dirgantara Indonesia, one of State Owned Enterprises engaging in the aerospace industry, targets to control 30% of world market for light and medium sized aircraft. One type of the aircrafts produced by PT. DI every year is CN-235. Currently, the cost of material procurement reaches 50% of the total cost of production. Material has a variety of characteristics, one of which is having a lifetime. The demand characteristic of the material with expiration for the CN-235 aircraft is deterministic. PT DI does not have any scientific background for its procurement of raw material policy. In addition, there are two methods of transportation used for delivering materials, i.e. by land and air. Each method has different lead time. Inventory policies used in this research are deterministic and probabilistic. Both deterministic and probabilistic single and multi-item inventory policies have order quantity, time to order, reorder point, and lead time as decision variables. The performance indicator for this research is total inventory cost. Inventory policy using the single item EOQ and considering expiration factor inventory results in a reduction in total costs up to 69.58% and multi item results in a decrease in total costs amounted to 71.16%. Inventory policy proposal using the model of a single item by considering expiration factor and lead time crashing cost results in a decrease in total costs amounted to 71.5% and multi item results in a decrease in total costs amounted to 71.62%. Subsequently, wasted expired materials, with the proposed models have been successfully decreased to 95%.

  6. 飞机撞击特大型 LNG 储罐全过程仿真分析%Whole process simulation analysis of aircraft's crashing into an extra-large LNG storage tank

    Institute of Scientific and Technical Information of China (English)

    葛庆子; 翁大根; 张瑞甫

    2016-01-01

    采用数值模拟方法对飞机撞击特大型 LNG 储罐的全过程进行仿真分析。分析中采用 LS-DYNA 有限元程序,考虑罐体、储液与保温层间的相互问题,建立了 F -15战斗机的 SPH 模型,对飞机材料的选择和参数确定进行了详细分析,并以 Riera 法为依据,对 F -15战斗机 SPH 模型撞击刚体所产生的荷载进行了对比验证,对比结果证明了 SPH 模型的可靠性和实用性。分析结果表明:撞击角度越大,外罐所承受的撞击能量越大,相应的内罐破坏越小,因此垂直撞击为最不利撞击角度;撞击高度对整体工况计算结果影响不大,储罐在经受215 m/s 撞击速度撞击下均出现了严重破坏;112 m/s 撞击速度时内罐尚有安全余量,160 m/s 撞击速度时内罐撞击中心区域内材料已达到极限应变,因此可认为目前设计方法设计的储罐所能承受的最大撞击速度为160 m/s。%Whole process of aircraft's crashing into an extra-large liquefied natural gas (LNG)storage tank was simulated using a numerical method.The LS-DYNA program was used to build the SPH model of a F-15 fighter considering the interaction of tank,LNG,and insulating layer.The plane's material model and parameters were chosen and analyzed.Based on Riera method,the comparison between the crash load obtained with the numerical method and that with the theoretical method was made to prove the reliability and practicability of the SPH model of a F-15 fighter. The analysis results revealed that the impact energy absorbed by the outer tank increases with increase in impact angle,so the vertical impact is the worst impact angle;the height of the aircraft impact position affects the response of the tank little;when the aircraft impact speed is 215m /s,the tank is destroyed seriously;if the speed reduces to 160m /s,the stress of the inner tank material approaches the maximum value,so 160m /s can be taken as the maximum

  7. The impact of pedestal turbulence and electron inertia on edge-localized-mode crashes

    Energy Technology Data Exchange (ETDEWEB)

    Xi, P. W. [FSC and State Key Lab of Nuclear Physics and Technology, Department of Physics, Peking University, Beijing 100871 (China); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Xu, X. Q. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon (Korea, Republic of); Center for Astrophysics and Space Sciences and Department of Physics, University of California San Diego, La Jolla, California 92093-0429 (United States)

    2014-05-15

    We demonstrate that the occurrence of Edge-Localized-Modes (ELM) crashes does not depend only on the linear peeling-ballooning threshold, but also relies on nonlinear processes. Wave-wave interaction constrains the growth time of a mode, thus inducing a shift in the criterion for triggering an ELM crash. An ELM crash requires the P-B growth rate to exceed a critical value γ>γ{sub c}, where γ{sub c} is set by 1/τ{sup ¯}{sub c}, and τ{sup ¯}{sub c} is the averaged mode phase coherence time. For 0<γ<γ{sub c}, P-B turbulence develops but drives enhanced turbulent transport. We also show that electron inertia dramatically changes the instability threshold when density is low. However, P-B turbulence alone cannot generate enough current transport to allow fast reconnection during an ELM crash.

  8. Motor Vehicle Crash-Related Subdural Hematoma from Real-World Head Impact Data

    OpenAIRE

    Urban, Jillian E.; Whitlow, Christopher T.; Edgerton, Colston A.; Powers, Alexander K.; Maldjian, Joseph A.; Stitzel, Joel D.

    2012-01-01

    Approximately 1,700,000 people sustain a traumatic brain injury (TBI) each year and motor vehicle crashes (MVCs) are a leading cause of hospitalization from TBI. Acute subdural hematoma (SDH) is a common intracranial injury that occurs in MVCs associated with high mortality and morbidity rates. In this study, SDH volume and midline shift have been analyzed in order to better understand occupant injury by correlating them to crash and occupant parameters. Fifty-seven head computed tomography (...

  9. Preliminary study of impact fragility to RC wall subjected to aircraft impact

    International Nuclear Information System (INIS)

    International experience has shown that internal and external hazards such as fires, earthquakes, and aircraft impacts can be significant safety contributors to the risk to infrastructures such as nuclear power plants. Since the aircraft accident at the World Trade Center (WTC) on September 11, 2001, an aircraft impact problem has been increasingly of the interest and is one of important categories of an unexpected external hazard field. To date, aircraft impact analyses has most focused on the response analysis to the target structures. However, this preliminary study carried out an impact fragility analysis to reinforced concrete (RC) wall subjected to an aircraft impact. The aircraft velocity is used as the important variable of this study. The impact analysis of the applied Ri era's forcing function is used by Abaqus/Explicit

  10. Post-crash fuel dispersal

    Energy Technology Data Exchange (ETDEWEB)

    Tieszen, S.R.

    1997-03-01

    This paper is a brief overview of work over the last several decades in understanding what occurs to jet fuel stored in aircraft fuel tanks on impact with the ground. Fuel dispersal is discussed in terms of the overall crash dynamics process and impact regimes are identified. In a generic sense, the types of flow regimes which can occur are identified and general descriptions of the processes are given. Examples of engineering level tools, both computational and experimental, which have applicability to analyzing the complex environments are presented. Finally, risk based decision is discussed as a quick means of identifying requirements for development of preventative or mitigation strategies, such as further work on the development of an anti-misting agent.

  11. Effect of weight, height and BMI on injury outcome in side impact crashes without airbag deployment.

    Science.gov (United States)

    Pal, Chinmoy; Tomosaburo, Okabe; Vimalathithan, K; Jeyabharath, M; Muthukumar, M; Satheesh, N; Narahari, S

    2014-11-01

    A comprehensive analysis is performed to evaluate the effect of weight, height and body mass index (BMI) of occupants on side impact injuries at different body regions. The accident dataset for this study is based on the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) for accident year 2000-08. The mean BMI values for driver and front passenger are estimated from all types of crashes using NASS database, which clearly indicates that mean BMI has been increasing over the years in the USA. To study the effect of BMI in side impact injuries, BMI was split into three groups namely (1) thin (BMI30). For more clear identification of the effect of BMI in side impact injuries, a minimum gap of three BMI is set in between each adjacent BMI groups. Car model years from MY1995-1999 to MY2000-2008 are chosen in order to identify the degree of influence of older and newer generation of cars in side impact injuries. Impact locations particularly side-front (F), side-center (P) and side-distributed (Y) are chosen for this analysis. Direction of force (DOF) considered for both near side and far side occupants are 8 o'clock, 9 o'clock, 10 o'clock and 2 o'clock, 3 o'clock and 4 o'clock respectively. Age occupant injuries. AIS2+ and AIS3+ injury risk in all body regions have been plotted for the selected three BMI groups of occupant, delta-V 0-60kmph, two sets (old and new) of car model years. The analysis is carried with three approaches: (a) injury risk percentage based on simple graphical method with respect to a single variable, (b) injury distribution method where the injuries are marked on the respective anatomical locations and (c) logistic regression, a statistical method, considers all the related variables together. Lower extremity injury risk appears to be high for thin BMI group. It is found that BMI does not have much influence on head injuries but it is influenced more by the height of the occupant. Results of logistic analysis suggest that

  12. Aircraft impact analysis for the HFBR. Revision 1

    International Nuclear Information System (INIS)

    This report presents an analysis performed to determine the annual frequency at which aircraft are expected to strike the High Flux Beam Reactor (HFBR) complex, located at Brookhaven National Laboratory. Since the HFBR is not hardened against light aircraft, this report considers the impact of military, commercial, twin engine and knee engine aircraft operating in the vicinity of the HFBR. The large volume of light aircraft operating in this area contributes heavily to the estimated annual impact frequency of 3.54E-05 impacts per year. There are two chapters and seven appendices in this report. The first chapter describes the airspace in the vicinity of the HFBR. This includes five airports, two major airways, one standard arrival route, as well as a significant volume of radar vectored and air-taxi traffic. The second chapter of this report presents the calculations by which the expected impact frequency was derived, and an assessment of the uncertainty in those calculations. The calculations were performed using the method outlined in the NRC Standard Review Plan. A separate set of calculations is presented for each of three sources of aircraft: airway traffic, Brookhaven Airport, and Calverton Airport. The appendices contain discussions and side calculations ancillary to the presentation in the second section. This includes a discussion of the data used to estimate traffic counts, information on accident rates, and several other points which would have only been distracting if included in the main discussion

  13. Brace for impact! A thesis on medical care following an airplane crash

    NARCIS (Netherlands)

    I.L.E. Postma

    2014-01-01

    In this thesis the events and management of a mass casualty incident (MCI) of an airplane crash are studied from a medical point of view. The incident is broken down into areas that are applicable to other MCIs. it is believed that the detailed study of an exceptional event can provide vital informa

  14. Brace for impact! A thesis on medical care following an airplane crash

    OpenAIRE

    Goslings, J.C.; Bloemers, F.W.; Bijlsma, T.S.; Heetveld, M.J.; Postma, I.L.E.

    2014-01-01

    In this thesis the events and management of a mass casualty incident (MCI) of an airplane crash are studied from a medical point of view. The incident is broken down into areas that are applicable to other MCIs. it is believed that the detailed study of an exceptional event can provide vital information for many other kinds of exceptional events.

  15. Low velocity blunt impacts on composite aircraft structures

    OpenAIRE

    Whisler, Daniel A.

    2009-01-01

    As composites are increasingly used for primary structures in commercial aircrafts, it is necessary to understand damage initiation for composites subject to low velocity impacts from service conditions, maintenance, and other ground equipment mishaps. In particular, collisions with ground vehicles can present a wide area, blunt impact. Therefore, the effects of bluntness of an impactor are of interest as this is related to both the external visual detectability of an impact event, as well as...

  16. Dual concrete containment design with optimal resistance to aircraft impact and earthquake. Design sensitivity supported by mathematical models

    International Nuclear Information System (INIS)

    As per current practice in most of the European countries, protection against aircraft crash is required. Notwithstanding some national regulatory differences, this protection is in general very expensive. Therefore an optimisation design process could be very advantageous. In fact the secondary containment design has to satisfy both impact and seismic requirements, as in many cases earthquake resistance is a lower limit for the thickness. The final optimal size is a compromise between the two requirements and it guarantees at the same time both the cheapest global configuration and the minimum impact on the existing design. The results of a large numerical analysis programme is presented, based on the most recent experimental data and computer codes. (author). 9 refs., 3 figs., 3 tabs

  17. Thoracic Injury Risk as a Function of Crash Severity – Car-to-car Side Impact Tests with WorldSID Compared to Real-life Crashes

    OpenAIRE

    Sunnevång, Cecilia; Rosén, Erik; Boström, Ola; Lechelt, Ulf

    2010-01-01

    Side airbags reduce the risk of fatal injury by approximately 30%. Due to limited real-life data the risk reducing effect for serious injury has not yet been established. Since side airbags are mainly designed and validated for crash severities used in available test procedures little is known regarding the protective effect when severity increases.

  18. Airplane crash

    International Nuclear Information System (INIS)

    In May, 1974, a severe airplane crash occurred near Springfield, llinois; the crew of three and a courier were killed. The plane was carrying a large container of controlled water with a slight amount of 60Co. A survey of the crash site by Air Force detectives and the radiological assistance team from Wright--Patterson Air Force Base indicated no radioactivity. Experiences of the incident were used to develop guidelines for future emergency preparedness

  19. Demographics, Velocity Distributions, and Impact Type as Predictors of AIS 4+ Head Injuries in Motor Vehicle Crashes.

    Science.gov (United States)

    Yoganandan, Narayan; Fitzharris, Michael; Pintar, Frank A; Stemper, Brian D; Rinaldi, James; Maiman, Dennis J; Fildes, Brian N

    2011-01-01

    The objective of the study was to determine differences between the United States-based NASS and CIREN and Australia-based ANCIS databases in occupant-, crash-, and vehicle-related parameters for AIS 4+ head injuries in motor vehicle crashes. Logistic regression analysis was performed to examine roles of the change in velocity (DV), crash type (frontal, far-side, nearside, rear impact), seatbelt use, and occupant position, gender, age, stature, and body mass in cranial traumas. Belted and unbelted non-ejected occupant (age >16 years) data from 1997-2006 were used for the NASS and CIREN datasets, and 2000-2010 for ANCIS. Vehicle model year, and occupant position and demographics including body mass index (BMI) data were obtained. Injuries were coded using AIS 1990-1998 update. Similarities were apparent across all databases: mean demographics were close to the mid-size anthropometry, mean BMI was in the normal to overweight range, and representations of extreme variations were uncommon. Side impacts contributed to over one-half of the ensemble, implying susceptibility to head trauma in this mode. Odds of sustaining head injury increased by 4% per unit increase in DV (OR: 1.04, 95% CI: 1.03-1.04, poccupants (OR: 0.48, 95% CI: 0.37-0.61, poccupant-related outcomes from the two continents indicate a worldwide need to revise the translation acceleration-based head injury criterion to include the angular component in an appropriate format for improved injury assessment and mitigation. PMID:22105402

  20. Local Impact Simulation of SC Wall Structures using Aircraft Engine Projectile

    International Nuclear Information System (INIS)

    SC wall structure developed for nuclear power plant buildings consists of plain concrete and two steel plates on both surface of the concrete, while RC structure consists of re bar and concrete. SC structure has higher scabbing resistance than RC structure due to the action of steel plate on the rear side of impact. Therefore SC structure is known as more effective structure from the viewpoint of aircraft crash than RC structure. However, most of the recent researches and experiments about local impact damage deal with RC structures, and the effect of re bar and steel plate is not considered reasonably. Although Walter et al. and Make-work et al. suggested a formula for evaluating perforation depth of steel plate covered RC walls, most of the previous researches about SC structure are focused on perforation and scabbing due to the impact of hard projectile, rather than soft projectile such as an aircraft. In this research a soft projectile, i. e. aircraft engine, is utilized for impact simulation of RC and SC walls. To evaluate local damage of SC wall structures, parametric study with the variables of wall thickness and steel ratio of the cover plate is performed, and the results are compared with those of RC structures. Since scabbing was prevented by the steel plates, penetration mode of damage was observed in SC walls while scabbing damage was occurred in RC walls. It is confirmed that the rear steel plate not only contains concrete debris, but also reduces the internal damage of the concrete walls. Penetration depth of SC walls did not largely vary due to the increasing steel ratio, and similar results to RC walls were observed when the wall thickness is larger than a certain value since the impact resistance of SC wall is mainly governed by the thickness of concrete part. Therefore, it is expected that similar level of impact resistance to RC structure can be produced with the minimum thickness of steel plates of SC structure. According to these results, SC

  1. The impact of technology on fighter aircraft requirements

    Science.gov (United States)

    Dollyhigh, S. M.; Foss, W. E., Jr.

    1985-01-01

    Technology integration studies were made to examine the impact of emerging technologies on fighter aircraft. The technologies examined included advances in aerodynamics, controls, structures, propulsion, and systems and were those which appeared capable of being ready for application by the turn of the century. A primary impetus behind large increases in figher capability will be the rapid increase in fighter engine thrust-to-weight ratio. High thrust-weight engines, integrated with other advanced and emerging technologies, can result in small extremely maneuverable fighter aircraft that have thrust-weight ratios of 1.4+ and weight one-half as much as today's fighters. Future fighter aircraft requirements are likely to include a turn capability in excess of 7g's throughout much of the maneuver envelope, post-stall maneuverability, STOVL or VTOL, and a single engine for low cost.

  2. A NASA study of the impact of technology on future multimission aircraft

    Science.gov (United States)

    Samuels, Jeffrey J.

    1992-01-01

    A conceptual aircraft design study was recently completed which compared three supersonic multimission tactical aircraft. The aircraft were evaluated in two technology timeframes and were sized with consistent methods and technology assumptions so that the aircraft could be compared in operational utility or cost analysis trends. The three aircraft are a carrier-based Fighter/Attack aircraft, a land-based Multirole Fighter, and a Short Takeoff/Vertical Landing (STOVL) aircraft. This paper describes the design study ground rules used and the aircraft designed. The aircraft descriptions include weights, dimensions and layout, design mission and maneuver performance, and fallout mission performance. The effect of changing technology and mission requirements on the STOVL aircraft and the impact of aircraft navalization are discussed. Also discussed are the effects on the STOVL aircraft of both Thrust/Weight required in hover and design mission radius.

  3. The brace position for passenger aircraft: a biomechanical evaluation

    OpenAIRE

    Brownson, Peter

    1993-01-01

    Hypothesis A modified brace position would help to prevent injury to some aircraft passengers in the event of an impact accident. Aim of Experiments To evaluate a modified crash brace position. Materials and Methods 1. Impact Testing Impact testing was performed at the RAF Institute of Aviation Medicine, Farnborough. Aircraft seats, mounted on a sled, were propelled down a track at an acceleration of 16G. A 50% Hybrid III dummy was used as the experimental model. Four ...

  4. Injury Differences Between Small and Large Overlap Frontal Crashes

    OpenAIRE

    Hallman, Jason J.; Yoganandan, Narayan; Pintar, Frank A.; Maiman, Dennis J.

    2011-01-01

    Because small overlap impacts have recently emerged as a crash mode posing great injury risk to occupants, a detailed analysis of US crash data was conducted using the NASS/CDS and CIREN databases. Frontal crashes were subcategorized into small overlap impact (SOI) and large overlap impact (LOI) using crash and crush characteristics from the datasets. Injuries to head, spine, chest, hip and pelvis, and lower extremities were parsed and compared between crash types. MAIS 3+ occupants in NASS/C...

  5. Delamination Modeling of Composites for Improved Crash Analysis

    Science.gov (United States)

    Fleming, David C.

    1999-01-01

    Finite element crash modeling of composite structures is limited by the inability of current commercial crash codes to accurately model delamination growth. Efforts are made to implement and assess delamination modeling techniques using a current finite element crash code, MSC/DYTRAN. Three methods are evaluated, including a straightforward method based on monitoring forces in elements or constraints representing an interface; a cohesive fracture model proposed in the literature; and the virtual crack closure technique commonly used in fracture mechanics. Results are compared with dynamic double cantilever beam test data from the literature. Examples show that it is possible to accurately model delamination propagation in this case. However, the computational demands required for accurate solution are great and reliable property data may not be available to support general crash modeling efforts. Additional examples are modeled including an impact-loaded beam, damage initiation in laminated crushing specimens, and a scaled aircraft subfloor structures in which composite sandwich structures are used as energy-absorbing elements. These examples illustrate some of the difficulties in modeling delamination as part of a finite element crash analysis.

  6. Weather Conditions, Weather Information and Car Crashes

    OpenAIRE

    Adriaan Perrels; Athanasios Votsis; Väinö Nurmi; Karoliina Pilli-Sihvola

    2015-01-01

    Road traffic safety is the result of a complex interaction of factors, and causes behind road vehicle crashes require different measures to reduce their impacts. This study assesses how strongly the variation in daily winter crash rates associates with weather conditions in Finland. This is done by illustrating trends and spatiotemporal variation in the crash rates, by showing how a GIS application can evidence the association between temporary rises in regional crash rates and the occurrence...

  7. Structural health monitoring and impact detection for primary aircraft structures

    Science.gov (United States)

    Kosters, Eric; van Els, Thomas J.

    2010-04-01

    The increasing use of thermoplastic carbon fiber-reinforced plastic (CFRP) materials in the aerospace industry for primary aircraft structures, such as wing leading-edge surfaces and fuselage sections, has led to rapid growth in the field of structural health monitoring (SHM). Impact, vibration, and load can all cause failure, such as delamination and matrix cracking, in composite materials. Moreover, the internal material damage can occur without being visible to the human eye, making inspection of and clear insight into structural integrity difficult using currently available evaluation methods. Here, we describe the detection of impact and its localization in materials and structures by high-speed interrogation of multiple-fiber Bragg grating (FBG) sensors mounted on a composite aircraft component.

  8. The deceleration of aircraft in overrun accidents from the point of first impact to the end of the wreckage path

    Directory of Open Access Journals (Sweden)

    David Pitfield

    2015-02-01

    Full Text Available Purpose: This paper outlines previous attempts to model aircraft deceleration and using a newer database containing a greater number of observations tries to refine the model.Design/Methodology: It is noted that data inadequacies still necessitate the estimation of a given acceleration for the aircraft wreckage path, but that there are more opportunities to change the intercept in a regression model to reflect categorical and dummy variables that proxy factors such as runway condition, the degree of control exercised by the pilot during the crash, the speed at the point of first impact (hereafter POFI, headwind, rain, characteristics of the terrain on the wreckage path  and aborted take-offs. Findings: The contribution of some of the explanatory variables can be seen. It is a shame other potential influences are not found to be significant. It is important to understand deceleration so that the wreckage location of aircraft accidents can be understood. This then gives guidance of appropriate runway safety areas. Originality/ value: This is the first time this has been attempted on the expanded accident database.

  9. Aircraft noise reduction technology. [to show impact on individuals and communities, component noise sources, and operational procedures to reduce impact

    Science.gov (United States)

    1973-01-01

    Aircraft and airport noise reduction technology programs conducted by NASA are presented. The subjects discussed are: (1) effects of aircraft noise on individuals and communities, (2) status of aircraft source noise technology, (3) operational procedures to reduce the impact of aircraft noise, and (4) NASA relations with military services in aircraft noise problems. References to more detailed technical literature on the subjects discussed are included.

  10. Effects from airplane crashes and gas explosions to Leningrad nuclear plant

    Energy Technology Data Exchange (ETDEWEB)

    Junttila, K.; Varpasuo, P. [IVO Power Engineering Oy, Vantaa (Finland)

    1998-12-31

    In this study the effects of aircraft crash and gas explosion to Leningrad Nuclear Power Plant has been researched. One of the two reactor buildings is modeled with finite element method using the pre-processor program MSC/PATRAN and analyzed with MSC/NASTRAN analysis program. In MSC/PATRAN or FEMAP, which is a pre-processor program of MSC/NASTRAN for Windows, the reactor building of the plant has been modeled with shell and beam elements and the load sets describing the aircraft crash and gas explosion have been developed. The crash loads are from Cessna 210 civil airplane crash with impact velocity 360 km/h and maximum impact force of 7 MN and Phantom RF-43 military airplane crash with impact velocity 215 m/s and with maximum impact force of 110 MN. The gas explosion pressure wave simulates the deflagration wave with maximum pressure of 0,045 MPa. Seven Cessna 210 airplane crash locations, two Phantom RF-43 airplane crash locations and one gas explosion load case is modeled. Airplane crash loads were from different directions and to different points of impact in the reactor building. The gas explosion load was assumed to affect the reactor building from one side parallel to one of the global coordinate axes of the model. With MSC/NASTRAN reactions from loads are analyzed. All loads were timedependent; their magnitude varied with time and consequently the analysis was carried out with the aid of transient response analysis. Time step in Cessna 210 analysis was 0,003 s and in Phantom RF-43 and gas explosion analyses 0,01 s. The greatest displacement from Cessna 210 loads was 12 mm and from Phantom RF-43 load 344 mm. The last value shows that construction would fail with that load. The greatest displacement from gas explosion load was 68 mm. Stresses are not so interesting in this preliminary analysis of the effects, but they are shown in pictures embedded in the report text. Displacements were greatest in upper part of the reactor building, where no intersections

  11. Modelling the impact of aircraft emissions on atmospheric composition

    Science.gov (United States)

    Wasiuk, D. K.; Lowenberg, M. H.; Shallcross, D. E.

    2012-12-01

    Emissions of the trace gases CO2, CO, H2O, HC, NOx, and SOx that have the potential to perturb large scale atmospheric composition are accumulating in the atmosphere at an unprecedented rate as the demand for air traffic continues to grow. We investigate the global and regional effects of aircraft emissions on the atmosphere and climate using mathematical modelling, sensitivity simulations, and perturbation simulations and present historical and spatial distribution evolution of the global and regional number of departures, fuel burn and emissions. A comprehensive aircraft movement database spanning years 2005 - 2012, covering 225 countries and over 223 million departures on approximately 41000 unique routes serves as a basis for our investigation. We combine air traffic data with output from an aircraft performance model (fuel burn and emissions) including 80 distinct aircraft types, representing 216 of all the aircraft flown in the world in 2005 - 2012. This accounts for fuel burn and emissions for 99.5% of the total number of departures during that time. Simulations are being performed using a state of the art 3D Lagrangian global chemical transport model (CTM) CRI-STOCHEM for simulation of tropospheric chemistry. The model is applied with the CRI (Common Representative Intermediates) chemistry scheme with 220 chemical species, and 609 reactions. This allows us to study in detail the chemical cycles driven by NOx, governing the rate of formation of O3 which controls the production of OH and indirectly determines the lifetime of other greenhouse gases. We also investigate the impact of the Eyjafjallajökull eruption on the European air traffic and present a model response to the perturbation of NOx emissions that followed.

  12. Exploring the impacts of factors contributing to tram-involved serious injury crashes on Melbourne tram routes.

    Science.gov (United States)

    Naznin, Farhana; Currie, Graham; Logan, David

    2016-09-01

    Previous research is limited regarding factors influencing tram-involved serious injury crashes. The aim of this study is to identify key vehicle, road, environment and driver related factors associated with tram-involved serious injury crashes. Using a binary logistic regression modelling approach, the following factors were identified to be significant in influencing tram-involved fatal crashes in Melbourne: tram floor height, tram age, season, traffic volume, tram lane priority and tram travel speed. Low floor trams, older trams, tram priority lanes and higher tram travelling speeds are more likely to increase tram-involved fatal crashes. Higher traffic volume decreases the likelihood of serious crashes. Fatal crashes are more likely to occur during spring and summer. Findings from this study may offer ideas for future research in the area of tram safety and help to develop countermeasures to prevent specific fatality types from occurring. PMID:27352035

  13. Economic impact of fuel properties on turbine powered business aircraft

    Science.gov (United States)

    Powell, F. D.

    1984-01-01

    The principal objective was to estimate the economic impact on the turbine-powered business aviation fleet of potential changes in the composition and properties of aviation fuel. Secondary objectives include estimation of the sensitivity of costs to specific fuel properties, and an assessment of the directions in which further research should be directed. The study was based on the published characteristics of typical and specific modern aircraft in three classes; heavy jet, light jet, and turboprop. Missions of these aircraft were simulated by computer methods for each aircraft for several range and payload combinations, and assumed atmospheric temperatures ranging from nominal to extremely cold. Five fuels were selected for comparison with the reference fuel, nominal Jet A. An overview of the data, the mathematic models, the data reduction and analysis procedure, and the results of the study are given. The direct operating costs of the study fuels are compared with that of the reference fuel in the 1990 time-frame, and the anticipated fleet costs and fuel break-even costs are estimated.

  14. European Commission research on aircraft impacts in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Amanatidis, G.T.; Angeletti, G. [European Commission (CEC), Brussels (Belgium)

    1997-12-31

    Aircraft engines release in the troposphere and lower stratosphere a number of chemical compounds (NO{sub x}, CO{sub 2}, CO, H{sub 2}O, hydrocarbons, sulphur, soot, etc.) which could potentially affect the ozone layer and the climate through chemical, dynamical and radiative changes. The global amount of gases and particles emitted by current subsonic and projected supersonic aircraft fleets can be estimated, but significant uncertainties remain about the fate of these emissions in the atmosphere. The European efforts concerning these potential atmospheric impacts of aircraft emissions are conducted by the Environment and Climate Research Programme of the European Commission (EC) as well as by national programmes of the Member States of the European Union (EU). The European research activities in this field, are described, divided for practical reasons in two periods. The first includes activities supported under the 3. Framework Programme for R and D activities which covered the period from 1992 up to 1996, while the second period has started in early 1996 and is supported under the 4. Framework Programme. (R.P.) 6 refs.

  15. Crash energy absorption of two-segment crash box with holes under frontal load

    Science.gov (United States)

    Choiron, Moch. Agus; Sudjito, Hidayati, Nafisah Arina

    2016-03-01

    Crash box is one of the passive safety components which designed as an impact energy absorber during collision. Crash box designs have been developed in order to obtain the optimum crashworthiness performance. Circular cross section was first investigated with one segment design, it rather influenced by its length which is being sensitive to the buckling occurrence. In this study, the two-segment crash box design with additional holes is investigated and deformation behavior and crash energy absorption are observed. The crash box modelling is performed by finite element analysis. The crash test components were impactor, crash box, and fixed rigid base. Impactor and the fixed base material are modelled as a rigid, and crash box material as bilinear isotropic hardening. Crash box length of 100 mm and frontal crash velocity of 16 km/jam are selected. Crash box material of Aluminum Alloy is used. Based on simulation results, it can be shown that holes configuration with 2 holes and ¾ length locations have the largest crash energy absorption. This condition associated with deformation pattern, this crash box model produces axisymmetric mode than other models.

  16. Aircraft

    Science.gov (United States)

    Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

    1998-01-01

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

  17. Brain Injury Differences in Frontal Impact Crash Using Different Simulation Strategies

    Science.gov (United States)

    Li, Dao; Ma, Chunsheng; Shen, Ming; Li, Peiyu; Zhang, Jinhuan

    2015-01-01

    In the real world crashes, brain injury is one of the leading causes of deaths. Using isolated human head finite element (FE) model to study the brain injury patterns and metrics has been a simplified methodology widely adopted, since it costs significantly lower computation resources than a whole human body model does. However, the degree of precision of this simplification remains questionable. This study compared these two kinds of methods: (1) using a whole human body model carried on the sled model and (2) using an isolated head model with prescribed head motions, to study the brain injury. The distribution of the von Mises stress (VMS), maximum principal strain (MPS), and cumulative strain damage measure (CSDM) was used to compare the two methods. The results showed that the VMS of brain mainly concentrated at the lower cerebrum and occipitotemporal region close to the cerebellum. The isolated head modelling strategy predicted higher levels of MPS and CSDM 5%, while the difference is small in CSDM 10% comparison. It suggests that isolated head model may not equivalently reflect the strain levels below the 10% compared to the whole human body model. PMID:26495029

  18. Impact of aircraft emissions on the atmospheric chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Dameris, M.; Sausen, R.; Grewe, V.; Koehler, I.; Ponater, M. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere; Steil, B. [Max-Planck-Inst. fuer Meteorologie, Hamburg (Germany); Bruehl, Ch. [Max-Planck-Inst. fuer Chemie (Otto-Hahn-Institut), Mainz (Germany)

    1997-12-31

    A hierarchy of models of different complexity has been applied to estimate the impact of aircraft NO{sub x} emissions on atmospheric chemistry. The global circulation model ECHAM3 has been coupled with two types of chemistry modules. The first of these describes only a simplified (linear) NO{sub x} and HNO{sub 3} chemistry while the second one is a comprehensive chemistry module (CHEM), describing tropospheric and stratospheric chemistry including photochemical reactions and heterogeneous reactions on sulphate aerosols and PSCs. The module CHEM has been coupled either off-line or with feedback via the ozone concentration. First results of multilayer integrations (over decades) are discussed. (author) 27 refs.

  19. On the methods and examples of aircraft impact analysis

    International Nuclear Information System (INIS)

    Conclusions: Aircraft impact analysis can be performed today within feasible run times using PCs and available advanced commercial finite element software tools. Adequate element and material model technologies exist. Explicit time integration enables analysis of very large deformation Missile/Target impacts. Meshless/particle based methods may be beneficial for large deformation concrete “punching shear” analysis – potentially solves the “element erosion” problem associated with FE, but are not generally implemented yet in major commercial software. Verification of the complicated modeling technologies continues to be a challenge. Not much work has been done yet on ACI shock loading – redundant and physically separated safety trains key to success. Analysis approach and detail should be “balanced” - commensurate with the significant uncertainties - do not “over-do” details of some parts of the model (e.g., the plane) and the analysis

  20. Structural capacity assessment of a generic pre-stressed concrete containment structure under aircraft impact

    International Nuclear Information System (INIS)

    The studied containment expressed adequate capacity to resist impact loads in the upper range of the studied diapason. The aircraft impact capacity of the containment for impact in the upper part of the cylindrical shell is about 25‐30% higher than the capacity for impact in the middle part of the cylindrical shell. The obtained fragility curves reefed to MoA can be then used for various additional calculations in the safety assessment of nuclear facilities under aircraft impact

  1. Comparison of Response between RC and SC Containment Structures Subjected to Aircraft Impact

    International Nuclear Information System (INIS)

    Since the aircraft terror to the World Trade Center (WTC) on September 11, 2001, an aircraft impact problem has been increasingly interested. The possibilities of aircraft impacts against nuclear power plants are one of important category. To date, the impact load of the analysis on aircraft impacts has been applied to target structures in local areas by using the impact force-time history function of Riera. However, Riera forcing function is not recommended at the expectation of unreasonable damage or perforation to target structures. The numerical analysis of rc and sc containment structures subjected to aircraft impact is performed by using the AUTODYN-3D. It is carried out the four different types for RC and SC structures. Thus, in this study, the different behaviors of containment structures and the safety of SC structure are expected

  2. Exploring the impacts of safety culture on immigrants' vulnerability in non-motorized crashes: a cross-sectional study.

    Science.gov (United States)

    Chen, Cynthia; Lin, Haiyun; Loo, Becky P Y

    2012-02-01

    Pedestrians and cyclists are a vulnerable group of road users. Immigrants are disproportionally represented in pedestrian and cyclist crashes. We postulate that the mismatch in safety culture between countries of their origin and the U.S.A. contribute to their vulnerability in pedestrian and cyclist crashes. Over time, the differences may disappear and immigrants' traffic behavior gravitates toward those of native-borns. We describe this process as safety assimilation. Using the pedestrian and cyclist crash database in New York City between 2001 and 2003, we examined the effects of foreign-born population, their countries of origin, and time of entry into the USA on census tract-level pedestrian and cyclist crashes. We find that neighborhoods with a higher concentration of immigrants, especially those from Latin America, Eastern Europe, and Asia, have more crashes. Our results also exhibit a pattern of the hypothesized safety assimilation process. The study suggests a higher level of vulnerability of immigrants to pedestrian and cyclist crashes. We propose that targeted policies and programs need to be developed for immigrants of different countries of origin. PMID:22173474

  3. Impact of Advanced Propeller Technology on Aircraft/Mission Characteristics of Several General Aviation Aircraft

    Science.gov (United States)

    Keiter, I. D.

    1982-01-01

    Studies of several General Aviation aircraft indicated that the application of advanced technologies to General Aviation propellers can reduce fuel consumption in future aircraft by a significant amount. Propeller blade weight reductions achieved through the use of composites, propeller efficiency and noise improvements achieved through the use of advanced concepts and improved propeller analytical design methods result in aircraft with lower operating cost, acquisition cost and gross weight.

  4. Dynamic of SDOF elastic-plastic system subjected to aircraft impact pulses

    International Nuclear Information System (INIS)

    In this paper the responses of elastic-plastic SDOF systems subjected to aircraft impact pulses are calculated. The results are compared with simpler pulse models and represented in the useful form of design charts. Two well-known approaches to seismic spectra are examined for the design of aircraft impact spectra. (orig.)

  5. Reaction-time relationship and structural design of reinforced concrete slabs and shells for aircraft impact

    International Nuclear Information System (INIS)

    This paper outlines a rational procedure by which reinforced concrete structures such as slabs and shells may be designed to retain the required structural integrity after an aircraft impact. The paper presents a new estimate of the reaction-time relationship for impacting aircraft. A new estimate of the punching shear capacity is proposed. In addition, a simple, rotational design procedure is presented. (Auth.)

  6. Impact biomechanics of the pelvis and lower limbs in occupants involved in an impact aircraft accident

    OpenAIRE

    Rowles, John M

    1992-01-01

    Impact biomechanics of the pelvis and lower limbs in occupants involved in an aircraft accident have been investigated using a variety of techniques. These techniques have been used to: 1) Explore whether the position adopted by the occupant of the plane at the time of impact had implications for the pelvic and lower limb injuries sustained. 2) Test and assess the relevance of hypothesised injury mechanisms for the pelvis and lower limbs, described in the automobile industry to that...

  7. Rail crash demonstration scenarios

    International Nuclear Information System (INIS)

    The paper describes the manner in which the rail crash scenario was selected for public demonstration. A simplified risk assessment led to the short listing of three contender scenarios involving a drop from a high level, a crash into an abutment and the crash of a train into a stationary flask. Predictive work led to the final selection of the train crash. (author)

  8. Motorcycle-related spinal injury: crash characteristics.

    Science.gov (United States)

    Zulkipli, Zarir Hafiz; Abdul Rahmat, Abdul Manap; Mohd Faudzi, Siti Atiqah; Paiman, Noor Faradila; Wong, Shaw Voon; Hassan, Ahamedali

    2012-11-01

    This study presents an analysis of crash characteristics of motorcyclists who sustained spinal injuries in motorcycle crashes. The aim of the study is to identify the salient crash characteristics that would help explain spinal injury risks for motorcyclists. Data were retrospectively collected from police case reports that were archived at MIROS from year 2005 to 2007. The data were categorized into two subcategories; the first group was motorcycle crashes with spinal injury (case) and the second group was motorcycle crashes without spinal injury (control). A total of 363 motorcyclists with spinal injury and 873 motorcyclists without spinal injury were identified and analyzed. Descriptive analysis and multivariate analysis were performed in order to determine the odds of each characteristic in contributing to spinal injury. Single vehicle crash, collision with fixed objects and crash configuration were found to have significant influence on motorcyclists in sustaining spinal injury (p<0.05). Although relatively few than other impact configurations, the rear-end impacted motorcyclist shows the highest risk of spinal injury. Helmets have helped to reduce head injury but they did not seem to offer corresponding protection for the spine in the study. With a growing number of young motorcyclists, further efforts are needed to find effective measures to help reduce the crash incidents and severity of spinal injury. In sum, the study provides some insights on some vital crash characteristics associated with spinal injury that can be further investigated to determine the appropriate counter-measures and prevention strategies to reduce spinal injury. PMID:23036400

  9. Specific problems concerning aircraft impact on nuclear containment vessels

    International Nuclear Information System (INIS)

    Due to the high population density, in Belgium PWR power plants are designed against aircraft impacts. A double wall is used for the containment shield. The lack of relevant data and specifications for such a loading on the non-prestressed external wall led us to determine the suitable safety criteria, the most appropriate materials to be used and the corresponding limit state design through dynamic and plastic analysis. Our technical choices and calculation results are summarized below. The safety criteria consisted mainly in adopting an ultimate limite state design for the allowable compression stress on concrete and the yield stress for the allowable tension stress on reinforcement. The plastic calculations have been carried out by successive approximations of the final state instead of a step by step analysis. An elastic dynamic analysis for an impact at the top of the dome has been made with the MARC program. It justified a D.L.F. of 1.15 for the shear forces. The ULS design without crack limitation made the use of high strength steel for the main reinforcement fully efficient. This allowed an important saving on the reinforcement cost. Static and dynamic tests have been carried out on high grade bars. Among other interesting results these tests showed a strain velocity of 100% per sec. and an increase in the ultimate strength under rapid loading

  10. Impact of Aircraft Performance Characteristics on Air Traffic Delays

    OpenAIRE

    Aydan CAVCAR; CAVCAR, Mustafa

    2004-01-01

    Air transportation has been suffering for decades from delays caused by air traffic congestion. This paper presents the effect of aircraft performance differences on air traffic delays. Rate of climb and cruising speeds of 70 different aircraft types are compared to demonstrate performance differences in the current transport aircraft fleet. The effect of these performance differences on air traffic delays is proved by a deterministic calculation of delays for a departure queue cons...

  11. Rapid evaluation of buildings and infrastructure to accidental and deliberate aircraft impact

    Energy Technology Data Exchange (ETDEWEB)

    Tennant, D., E-mail: tennant@wai.com [Weidlinger Associates, Inc., 6301 Indian School Road NE, Suite 501, Albuquerque, NM 87122 (United States); Levine, H., E-mail: levine@ca.wai.com [Weidlinger Associates, Inc., 399 W. El Camino Real, Suite 200, Mountain View, CA 94040 (United States); Mould, J.; Vaughan, D. [Weidlinger Associates, Inc., 399 W. El Camino Real, Suite 200, Mountain View, CA 94040 (United States)

    2014-04-01

    Recent events involving the impact of large transport aircraft such as the Boeing 767 and 757 into the World Trade Center Towers and the Pentagon have revealed the vulnerability of such structures to terrorist attack. Incidents involving smaller general aviation aircraft have shown the damage that this class of plane can do beyond a protected perimeter. These incidents have elicited inquiries with regard to the effects of impacts of these aircraft types into other critical facilities including aboveground and below ground storage facilities, nuclear power plants, damns and other military and civilian installations. A significant capability to evaluate these threats has been developed during the past 10 years. Small medium and large aircraft have been impacted into buried and aboveground reinforced concrete and light steel frame storage facilities. Both explicit aircraft models and Riera functions (a simplified aircraft impact loading function) have been used to generate an extensive data base. The effects of engines impacting have been studied separately as penetrators. Illustrated in this paper is validation of computational tools for impacts into structures and the initial development of a generalized evaluation tool for rapid evaluation of threats and consequence of aircraft impact into protected facilities.

  12. Rapid evaluation of buildings and infrastructure to accidental and deliberate aircraft impact

    International Nuclear Information System (INIS)

    Recent events involving the impact of large transport aircraft such as the Boeing 767 and 757 into the World Trade Center Towers and the Pentagon have revealed the vulnerability of such structures to terrorist attack. Incidents involving smaller general aviation aircraft have shown the damage that this class of plane can do beyond a protected perimeter. These incidents have elicited inquiries with regard to the effects of impacts of these aircraft types into other critical facilities including aboveground and below ground storage facilities, nuclear power plants, damns and other military and civilian installations. A significant capability to evaluate these threats has been developed during the past 10 years. Small medium and large aircraft have been impacted into buried and aboveground reinforced concrete and light steel frame storage facilities. Both explicit aircraft models and Riera functions (a simplified aircraft impact loading function) have been used to generate an extensive data base. The effects of engines impacting have been studied separately as penetrators. Illustrated in this paper is validation of computational tools for impacts into structures and the initial development of a generalized evaluation tool for rapid evaluation of threats and consequence of aircraft impact into protected facilities

  13. 14 CFR 29.952 - Fuel system crash resistance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system crash resistance. 29.952... crash resistance. Unless other means acceptable to the Administrator are employed to minimize the hazard of fuel fires to occupants following an otherwise survivable impact (crash landing), the fuel...

  14. 14 CFR 27.952 - Fuel system crash resistance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system crash resistance. 27.952... crash resistance. Unless other means acceptable to the Administrator are employed to minimize the hazard of fuel fires to occupants following an otherwise survivable impact (crash landing), the fuel...

  15. 76 FR 3540 - U.S. Advanced Boiling Water Reactor Aircraft Impact Design Certification Amendment

    Science.gov (United States)

    2011-01-20

    ... COMMISSION 10 CFR Part 52 RIN 3150-AI84 U.S. Advanced Boiling Water Reactor Aircraft Impact Design... the U.S. Advanced Boiling Water Reactor (ABWR) standard plant design to comply with the NRC's aircraft...--Design Certification Rule for the U.S. Advanced Boiling Water Reactor IV. Section-by-Section Analysis...

  16. A NASA study of the impact of technology on future carrier based tactical aircraft - Overview

    Science.gov (United States)

    Wilson, S. B., III

    1992-01-01

    This paper examines the impact of technology on future carrier based tactical aircraft. The results were used in the Center for Naval Analysis Future Carrier Study. The NASA Team designed three classes of aircraft ('Fighter', 'Attack', and 'Multimission') with two different technology levels. The Multimission aircraft were further analyzed by examining the penalty on the aircraft for both catapult launch/arrested landing recovery (Cat/trap) and short take-off/vertical landing (STOVL). The study showed the so-called STOVL penalty was reduced by engine technology and the next generation Strike Fighter will pay more penalty for Cat/trap than for STOVL capability.

  17. Database on aircraft accidents

    International Nuclear Information System (INIS)

    The Reactor Safety Subcommittee in the Nuclear Safety and Preservation Committee published the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' as the standard method for evaluating probability of aircraft crash into nuclear reactor facilities in July 2002. In response to the report, Japan Nuclear Energy Safety Organization has been collecting open information on aircraft accidents of commercial airplanes, self-defense force (SDF) airplanes and US force airplanes every year since 2003, sorting out them and developing the database of aircraft accidents for latest 20 years to evaluate probability of aircraft crash into nuclear reactor facilities. This year, the database was revised by adding aircraft accidents in 2010 to the existing database and deleting aircraft accidents in 1991 from it, resulting in development of the revised 2011 database for latest 20 years from 1991 to 2010. Furthermore, the flight information on commercial aircrafts was also collected to develop the flight database for latest 20 years from 1991 to 2010 to evaluate probability of aircraft crash into reactor facilities. The method for developing the database of aircraft accidents to evaluate probability of aircraft crash into reactor facilities is based on the report 'The criteria on assessment of probability of aircraft crash into light water reactor facilities' described above. The 2011 revised database for latest 20 years from 1991 to 2010 shows the followings. The trend of the 2011 database changes little as compared to the last year's one. (1) The data of commercial aircraft accidents is based on 'Aircraft accident investigation reports of Japan transport safety board' of Ministry of Land, Infrastructure, Transport and Tourism. 4 large fixed-wing aircraft accidents, 58 small fixed-wing aircraft accidents, 5 large bladed aircraft accidents and 114 small bladed aircraft accidents occurred. The relevant accidents for evaluating

  18. Elastic response of a German HTR-Modul reactor building to aircraft impact

    International Nuclear Information System (INIS)

    The paper presents the results of a study carried out for a German HTR-Modul reactor building when subjected to aircraft impact. The structural analysis has been carried out using finite element package program PERMAS. The soil-structure interaction has also been considered using springs. Eigenmode values have been calculated. The elastic response of the building to aircraft impact has been studied by analysing for the stresses and the deflections. (author)

  19. Impact of Aircraft NOx Emission on NOx and Ozone over China

    Institute of Scientific and Technical Information of China (English)

    刘煜; I.S.A.ISAKSEN; J.K.SUNDET; 周秀骥; 马建中

    2003-01-01

    A three-dimensional global chemistry transport model (OSLO CTM2) is used to investigate the impact of subsonic aircraft NOx emission on NOz and ozone over China in terms of a year 2000 scenario of subsonic aircraft NOx emission. The results show that subsonic aircraft NOx emission significantly affects northern China, which makes NOx at 250 hPa increase by about 50 pptv with the highest percentage of 60% in January, and leading to an ozone increase of 8 ppbv with 5% relative change in April. The NOx increase is mainly attributed to the transport process, but ozone increase is produced by the chemical process. The NOx increases by less than 10 pptv by virtue of subsonic aircraft NOx emission over China,and ozone changes less than 0.4 ppbv. When subsonic aircraft NOx emission over China is doubled, its influence is still relatively small.

  20. Damage evaluation of 500 MWe Indian Pressurized Heavy Water Reactor nuclear containment for aircraft impact

    International Nuclear Information System (INIS)

    Safety assessment of Indian nuclear containments has been carried out for aircraft impact. The loading time history for Boeing and Airbus categories of aircrafts is generated based on the principle of momentum transfer of crushable aircrafts. The case studies include the analysis of BWR Mark III containment as a benchmark problem and analyses of Pressurised Heavy Water Reactor containment (inner and outer containment) for impulsive loading due to aircraft impact. Initially, the load is applied on outer containment wall model and subsequently the load is transferred to inner containment after the local perforation of the outer containment wall is noticed in the transient simulation. The analysis methodology evolved in the present work would be useful for studying the behavior of double containment walls and multi barrier structural configurations for aircraft impact with higher energies. The present analysis illustrates that with the provision of double containments for Indian nuclear power plants, adequate reserve strength is available for the case of an extremely low probability event of missile impact generated due to the commercial aircrafts operated in India

  1. The effects of aircraft on climate and pollution. Part II: 20-year impacts of exhaust from all commercial aircraft worldwide treated individually at the subgrid scale.

    Science.gov (United States)

    Jacobson, M Z; Wilkerson, J T; Naiman, A D; Lele, S K

    2013-01-01

    This study examines the 20-year impacts of emissions from all commercial aircraft flights worldwide on climate, cloudiness, and atmospheric composition. Aircraft emissions from each individual flight worldwide were modeled to evolve from the subgrid to grid scale with the global model described and evaluated in Part I of this study. Simulations with and without aircraft emissions were run for 20 years. Aircraft emissions were found to be responsible for -6% of Arctic surface global warming to date, -1.3% of total surface global warming, and -4% of global upper tropospheric warming. Arctic warming due to aircraft slightly decreased Arctic sea ice area. Longer simulations should result in more warming due to the further increase in CO2. Aircraft increased atmospheric stability below cruise altitude and decreased it above cruise altitude. The increase in stability decreased cumulus convection in favor of increased stratiform cloudiness. Aircraft increased total cloud fraction on average. Aircraft increased surface and upper tropospheric ozone by -0.4% and -2.5%, respectively and surface and upper-tropospheric peroxyacetyl nitrate (PAN) by -0.1% and -5%, respectively. Aircraft emissions increased tropospheric OH, decreasing column CO and CH4 by -1.7% and -0.9%, respectively. Aircraft emissions increased human mortality worldwide by -620 (-240 to 4770) deaths per year, with half due to ozone and the rest to particulate matter less than 2.5 micrometers in diameter (PM2.5). PMID:24601012

  2. Process analysis of the modelled 3-D mesoscale impact of aircraft emissions on the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Hendricks, J.; Ebel, A.; Lippert, E.; Petry, H. [Koeln Univ. (Germany). Inst. fuer Geophysik und Meterorologie

    1997-12-31

    A mesoscale chemistry transport model is applied to study the impact of aircraft emissions on the atmospheric trace gas composition. A special analysis of the simulations is conducted to separate the effects of chemistry, transport, diffusion and cloud processes on the transformation of the exhausts of a subsonic fleet cruising over the North Atlantic. The aircraft induced ozone production strongly depends on the tropopause height and the cruise altitude. Aircraft emissions may undergo an effective downward transport under the influence of stratosphere-troposphere exchange activity. (author) 12 refs.

  3. Impact of the pedestal plasma density on dynamics of edge localized mode crashes and energy loss scaling

    Energy Technology Data Exchange (ETDEWEB)

    Xu, X. Q., E-mail: xxu@llnl.gov [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Ma, J. F. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Institute for Fusion Studies, University of Texas, Austin, Texas 78712 (United States); Li, G. Q. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China)

    2014-12-15

    The latest BOUT++ studies show an emerging understanding of dynamics of edge localized mode (ELM) crashes and the consistent collisionality scaling of ELM energy losses with the world multi-tokamak database. A series of BOUT++ simulations are conducted to investigate the scaling characteristics of the ELM energy losses vs collisionality via a density scan. Linear results demonstrate that as the pedestal collisionality decreases, the growth rate of the peeling-ballooning modes decreases for high n but increases for low n (1 < n < 5), therefore the width of the growth rate spectrum γ(n) becomes narrower and the peak growth shifts to lower n. Nonlinear BOUT++ simulations show a two-stage process of ELM crash evolution of (i) initial bursts of pressure blob and void creation and (ii) inward void propagation. The inward void propagation stirs the top of pedestal plasma and yields an increasing ELM size with decreasing collisionality after a series of micro-bursts. The pedestal plasma density plays a major role in determining the ELM energy loss through its effect on the edge bootstrap current and ion diamagnetic stabilization. The critical trend emerges as a transition (1) linearly from ballooning-dominated states at high collisionality to peeling-dominated states at low collisionality with decreasing density and (2) nonlinearly from turbulence spreading dynamics at high collisionality into avalanche-like dynamics at low collisionality.

  4. AP statistics crash course

    CERN Document Server

    D'Alessio, Michael

    2012-01-01

    AP Statistics Crash Course - Gets You a Higher Advanced Placement Score in Less Time Crash Course is perfect for the time-crunched student, the last-minute studier, or anyone who wants a refresher on the subject. AP Statistics Crash Course gives you: Targeted, Focused Review - Study Only What You Need to Know Crash Course is based on an in-depth analysis of the AP Statistics course description outline and actual Advanced Placement test questions. It covers only the information tested on the exam, so you can make the most of your valuable study time. Our easy-to-read format covers: exploring da

  5. Aircraft impact risk assessment data base for assessment of fixed wing air carrier impact risk in the vicinity of airports

    International Nuclear Information System (INIS)

    The FIXED WING AIRCRAFT accidents occurring to US air carriers during the years 1956 through 1977 are listed, with those resulting in impact within five miles of airports in the contiguous US being considered in detail as to location of impact relative to the airport runways

  6. Weather Conditions, Weather Information and Car Crashes

    Directory of Open Access Journals (Sweden)

    Adriaan Perrels

    2015-11-01

    Full Text Available Road traffic safety is the result of a complex interaction of factors, and causes behind road vehicle crashes require different measures to reduce their impacts. This study assesses how strongly the variation in daily winter crash rates associates with weather conditions in Finland. This is done by illustrating trends and spatiotemporal variation in the crash rates, by showing how a GIS application can evidence the association between temporary rises in regional crash rates and the occurrence of bad weather, and with a regression model on crash rate sensitivity to adverse weather conditions. The analysis indicates that a base rate of crashes depending on non-weather factors exists, and some combinations of extreme weather conditions are able to substantially push up crash rates on days with bad weather. Some spatial causation factors, such as variation of geophysical characteristics causing systematic differences in the distributions of weather variables, exist. Yet, even in winter, non-spatial factors are normally more significant. GIS data can support optimal deployment of rescue services and enhance in-depth quantitative analysis by helping to identify the most appropriate spatial and temporal resolutions. However, the supportive role of GIS should not be inferred as existence of highly significant spatial causation.

  7. Occupant Responses in a Full-Scale Crash Test of the Sikorsky ACAP Helicopter

    Science.gov (United States)

    Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard L.; McEntire, Joseph; Lewis, Alan

    2002-01-01

    A full-scale crash test of the Sikorsky Advanced Composite Airframe Program (ACAP) helicopter was performed in 1999 to generate experimental data for correlation with a crash simulation developed using an explicit nonlinear, transient dynamic finite element code. The airframe was the residual flight test hardware from the ACAP program. For the test, the aircraft was outfitted with two crew and two troop seats, and four anthropomorphic test dummies. While the results of the impact test and crash simulation have been documented fairly extensively in the literature, the focus of this paper is to present the detailed occupant response data obtained from the crash test and to correlate the results with injury prediction models. These injury models include the Dynamic Response Index (DRI), the Head Injury Criteria (HIC), the spinal load requirement defined in FAR Part 27.562(c), and a comparison of the duration and magnitude of the occupant vertical acceleration responses with the Eiband whole-body acceleration tolerance curve.

  8. Improving aircraft accident forecasting for an integrated plutonium storage facility

    International Nuclear Information System (INIS)

    Aircraft accidents pose a quantifiable threat to facilities used to store and process surplus weapon-grade plutonium. The Department of Energy (DOE) recently published its first aircraft accident analysis guidelines: Accident Analysis for Aircraft Crash into Hazardous Facilities. This document establishes a hierarchy of procedures for estimating the small annual frequency for aircraft accidents that impact Pantex facilities and the even smaller frequency of hazardous material released to the environment. The standard establishes a screening threshold of 10-6 impacts per year; if the initial estimate of impact frequency for a facility is below this level, no further analysis is required. The Pantex Site-Wide Environmental Impact Statement (SWEIS) calculates the aircraft impact frequency to be above this screening level. The DOE Standard encourages more detailed analyses in such cases. This report presents three refinements, namely, removing retired small military aircraft from the accident rate database, correcting the conversion factor from military accident rates (accidents per 100,000 hours) to the rates used in the DOE model (accidents per flight phase), and adjusting the conditional probability of impact for general aviation to more accurately reflect pilot training and local conditions. This report documents a halving of the predicted frequency of an aircraft impact at Pantex and points toward further reductions

  9. Development of a human body finite element model with multiple muscles and their controller for estimating occupant motions and impact responses in frontal crash situations.

    Science.gov (United States)

    Iwamoto, Masami; Nakahira, Yuko; Kimpara, Hideyuki; Sugiyama, Takahiko; Min, Kyuengbo

    2012-10-01

    A few reports suggest differences in injury outcomes between cadaver tests and real-world accidents under almost similar conditions. This study hypothesized that muscle activity could primarily cause the differences, and then developed a human body finite element (FE) model with individual muscles. Each muscle was modeled as a hybrid model of bar elements with active properties and solid elements with passive properties. The model without muscle activation was firstly validated against five series of cadaver test data on impact responses in the anterior-posterior direction. The model with muscle activation levels estimated based on electromyography (EMG) data was secondly validated against four series of volunteer test data on bracing effects for stiffness and thickness of an upper arm muscle, and braced driver's responses under a static environment and a brake deceleration. A muscle controller using reinforcement learning (RL), which is a mathematical model of learning process in the basal ganglia associated with human postural controls, were newly proposed to estimate muscle activity in various occupant conditions including inattentive and attentive conditions. Control of individual muscles predicted by RL reproduced more human like head-neck motions than conventional control of two groups of agonist and antagonist muscles. The model and the controller demonstrated that head-neck motions of an occupant under an impact deceleration of frontal crash were different in between a bracing condition with maximal braking force and an occupant condition predicted by RL. The model and the controller have the potential to investigate muscular effects in various occupant conditions during frontal crashes. PMID:23625563

  10. A study to maximize the crash energy absorption efficiency within the limits of crash space

    International Nuclear Information System (INIS)

    The design of an engine room is important to protect the passenger from a crash impact by improving the absorption of the crash impact energy. The side member in the engine room absorbs most of the crash impact energy when the vehicle experiences a frontal crash. The side member is of two types: hat and 'U.' Analysis of the extent of energy absorption and the mechanism of the side member are necessary through a collapse mode in various load conditions. In this study, the design of experiments was used for evaluating the characteristics of the absorption of crash energy by side members through design variables. First, crash analysis was performed by experiment number extracted from the design of the experiment. Then, using the results of crash analysis, multiple regressions were conducted and sensitivity analysis performed for each design variable. Finally, the optimum design was developed for maximizing the absorption energy per unit weight considering various boundary conditions. In the present study, as a basic step for modeling the fatigue behavior of an extruded Al alloy cylinder, the fatigue crack growth data of the alloy was collected in two orientations. Microstructural analysis revealed that the material had recrystallized grains and clusters of constituent particles aligned in the direction of extrusion. Fatigue life of the samples revealed a shorter fatigue life representing a higher fatigue crack growth rate in the transverse direction

  11. Crash Under Investigation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The cause of a fatal cargo plane accident in Shanghai is still unknown The flight data recorder of the Zimbabwean cargo plane that crashed on November 28 at Shanghai Pudong International Airport has been found near the crash scene,local aviation control authorities said.

  12. Comparison of methodologies estimating emissions of aircraft pollutants, environmental impact assessment around airports

    International Nuclear Information System (INIS)

    Air transportation growth has increased continuously over the years. The rise in air transport activity has been accompanied by an increase in the amount of energy used to provide air transportation services. It is also assumed to increase environmental impacts, in particular pollutant emissions. Traditionally, the environmental impacts of atmospheric emissions from aircraft have been addressed in two separate ways; aircraft pollutant emissions occurring during the landing and take-off (LTO) phase (local pollutant emissions) which is the focus of this study, and the non-LTO phase (global/regional pollutant emissions). Aircraft pollutant emissions are an important source of pollution and directly or indirectly harmfully affect human health, ecosystems and cultural heritage. There are many methods to asses pollutant emissions used by various countries. However, using different and separate methodology will cause a variation in results, some lack of information and the use of certain methods will require justification and reliability that must be demonstrated and proven. In relation to this issue, this paper presents identification, comparison and reviews of some of the methodologies of aircraft pollutant assessment from the past, present and future expectations of some studies and projects focusing on emissions factors, fuel consumption, and uncertainty. This paper also provides reliable information on the impacts of aircraft pollutant emissions in short term and long term predictions.

  13. ATD Occupant Responses from Three Full-Scale General Aviation Crash Tests

    Science.gov (United States)

    Littell, Justin D.; Annett, Martin S.

    2016-01-01

    During the summer of 2015, three Cessna 172 General Aviation (GA) aircraft were crash tested at the Landing and Impact Research (LandIR) Facility at NASA Langley Research Center (LaRC). Three different crash scenarios were represented. The first test simulated a flare-to-stall emergency or hard landing onto a rigid surface such as a road or runway. The second test simulated a controlled flight into terrain with a nose down pitch of the aircraft, and the third test simulated a controlled flight into terrain with an attempt to unsuccessfully recover the aircraft immediately prior to impact, resulting in a tail strike condition. An on-board data acquisition system (DAS) captured 64 channels of airframe acceleration, along with accelerations and loads in two onboard Hybrid II 50th percentile Anthropomorphic Test Devices (ATDs) representing the pilot and copilot. Each of the three tests contained different airframe loading conditions and different types of restraints for both the pilot and co-pilot ATDs. The results show large differences in occupant response and restraint performance with varying likelihoods of occupant injury.

  14. Impact of supersonic and subsonic aircraft on ozone: Including heterogeneous chemical reaction mechanisms

    Science.gov (United States)

    Kinnison, Douglas E.; Wuebbles, Donald J.

    1994-01-01

    Preliminary calculations suggest that heterogeneous reactions are important in calculating the impact on ozone from emissions of trace gases from aircraft fleets. In this study, three heterogeneous chemical processes that occur on background sulfuric acid aerosols are included and their effects on O3, NO(x), Cl(x), HCl, N2O5, ClONO2 are calculated.

  15. Impact of supersonic and subsonic aircraft on ozone: Including heterogeneous chemical reaction mechanisms

    International Nuclear Information System (INIS)

    Preliminary calculations suggest that heterogeneous reactions are important in calculating the impact on ozone from emissions of trace gases from aircraft fleets. In this study, three heterogeneous chemical processes that occur on background sulfuric acid aerosols are included and their effects on O3, NOx, Clx, HCl, N2O5, ClONO2 are calculated

  16. Present and future impact of aircraft, road traffic and shipping emissions on global tropospheric ozone

    OpenAIRE

    B. Koffi; Szopa, S.; A. Cozic; Hauglustaine, D.; P. van Velthoven

    2010-01-01

    In this study, the LMDz-INCA climate-chemistry model and up-to-date global emission inventories are used to investigate the "present" (2000) and future (2050) impacts of transport emissions (road traffic, shipping and aircraft) on global tropospheric ozone. For the first time, both impacts of emissions and climate changes on transport-induced ozone are investigated. The 2000 transport emissions are shown to mainly affect ozone in the Northern Hemisphere, with a maximum increase of the tr...

  17. Present and future impact of aircraft, road traffic and shipping emissions on global tropospheric ozone

    OpenAIRE

    B. Koffi; Szopa, S.; A. Cozic; Hauglustaine, D.; P. van Velthoven

    2010-01-01

    In this study, the LMDz-INCA climate-chemistry model and up-to-date global emission inventories are used to investigate the "present" (2000) and future (2050) impacts of transport emissions (road traffic, shipping and aircraft) on global tropospheric ozone. For the first time, both impacts of emissions and climate changes on transport-induced ozone are investigated. The 2000 transport emissions are shown to mainly affect ozone in the Northern Hemisphere, with a maximum incre...

  18. Design study of a French nuclear plant under aircraft impact according to German guidelines

    International Nuclear Information System (INIS)

    Subject of the paper is the presentation of an aircraft protection for the reactor building and the electrical building of the French nuclear plant P'4 or N4 against the aircraft impact load conditions according to German guidelines. Furthermore, floor response spectra in the interior of the two buildings are evaluated for the induced vibrations resistant design of components. The presented solution leads to acceptable values of either necessary bending and stirrup reinforcements and of the level of equipment accelerations for the reactor building as well as for the electrical building. (author)

  19. Emergency Locator Transmitter System Performance During Three Full-Scale General Aviation Crash Tests

    Science.gov (United States)

    Littell, Justin D.; Stimson, Chad M.

    2016-01-01

    Full-scale crash tests were conducted on three Cessna 172 aircraft at NASA Langley Research Center's Landing and Impact Research facility during the summer of 2015. The purpose of the three tests was to evaluate the performance of commercially available Emergency Locator Transmitter (ELT) systems and support development of enhanced installation guidance. ELTs are used to provide location information to Search and Rescue (SAR) organizations in the event of an aviation distress situation, such as a crash. The crash tests simulated three differing severe but survivable crash conditions, in which it is expected that the onboard occupants have a reasonable chance of surviving the accident and would require assistance from SAR personnel. The first simulated an emergency landing onto a rigid surface, while the second and third simulated controlled flight into terrain. Multiple ELT systems were installed on each airplane according to federal regulations. The majority of the ELT systems performed nominally. In the systems which did not activate, post-test disassembly and inspection offered guidance for non-activation cause in some cases, while in others, no specific cause could be found. In a subset of installations purposely disregarding best practice guidelines, failure of the ELT-to-antenna cabling connections were found. Recommendations for enhanced installation guidance of ELT systems will be made to the Radio Technical Commission for Aeronautics (RTCA) Special Committee 229 for consideration for adoption in a future release of ELT minimum operational performance specifications. These recommendations will be based on the data gathered during this test series as well as a larger series of crash simulations using computer models that will be calibrated based on these data

  20. The Development of a Conical Composite Energy Absorber for Use in the Attenuation of Crash/Impact Loads

    Science.gov (United States)

    Littell, Justin D.

    2014-01-01

    A design for a novel light-weight conical shaped energy absorbing (EA) composite subfloor structure is proposed. This composite EA is fabricated using repeated alternating patterns of a conical geometry to form long beam structures which can be implemented as aircraft subfloor keel beams or frame sections. The geometrical features of this conical design, along with the hybrid composite materials used in the manufacturing process give a strength tailored to achieve a constant 25-40 g sustained crush load, small peak crush loads and long stroke limits. This report will discuss the geometrical design and fabrication methods, along with results from static and dynamic crush testing of 12-in. long subcomponents.

  1. Allegheny County Crash Data

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Contains locations and information about every crash incident reported to the police in Allegheny County from 2004 to 2015. Fields include injury severity,...

  2. Bubbles and market crashes

    CERN Document Server

    Youssefmir, M; Hogg, T; Youssefmir, Michael; Huberman, Bernardo; Hogg, Tad

    1994-01-01

    We present a dynamical theory of asset price bubbles that exhibits the appearance of bubbles and their subsequent crashes. We show that when speculative trends dominate over fundamental beliefs, bubbles form, leading to the growth of asset prices away from their fundamental value. This growth makes the system increasingly susceptible to any exogenous shock, thus eventually precipitating a crash. We also present computer experiments which in their aggregate behavior confirm the predictions of the theory.

  3. Currencies, Crises, and Crashes

    OpenAIRE

    Peter Kenen

    2002-01-01

    The emerging-market crises of the 1990s were characterized by crashes in exchange rates, credit flows, and output, and the currency crashes caused the other two. Because local banks and firms had large foreign-currency debts, the sharp depreciations of their countries' currencies had huge balance-sheet effects that led to an implosion of domestic credit flows, causing sharp falls in investment and output. It is wrong to blame the IMF for these calamitous outcomes. Nevertheless, the strategy a...

  4. Parametric Study on Important Variables of Aircraft Impact to Prestressed Concrete Containment Vessels

    International Nuclear Information System (INIS)

    In this paper, to find the damage parameter, it is necessary to use many analysis cases and the time reduction. Thus, this paper uses a revised version of Riera's method. Using this method, the response has been found a Prestressed Concrete Containments Vessels (PCCVs) subject to impact loading, and the results of the velocity and mass of the important parameters have been analyzed. To find the response of the PCCVs subjected to aircraft impact load, it is made that a variable forcing functions depending on the velocity and fuel in the paper. The velocity variation affects more than fuel percentage, and we expect that the severe damage of the PCCVs with the same material properties is subject to aircraft impact load (more than 200m/s and 70%)

  5. Assessing the environmental impacts of aircraft noise and emissions

    Science.gov (United States)

    Mahashabde, Anuja; Wolfe, Philip; Ashok, Akshay; Dorbian, Christopher; He, Qinxian; Fan, Alice; Lukachko, Stephen; Mozdzanowska, Aleksandra; Wollersheim, Christoph; Barrett, Steven R. H.; Locke, Maryalice; Waitz, Ian A.

    2011-01-01

    With the projected growth in demand for commercial aviation, many anticipate increased environmental impacts associated with noise, air quality, and climate change. Therefore, decision-makers and stakeholders are seeking policies, technologies, and operational procedures that balance environmental and economic interests. The main objective of this paper is to address shortcomings in current decision-making practices for aviation environmental policies. We review knowledge of the noise, air quality, and climate impacts of aviation, and demonstrate how including environmental impact assessment and quantifying uncertainties can enable a more comprehensive evaluation of aviation environmental policies. A comparison is presented between the cost-effectiveness analysis currently used for aviation environmental policy decision-making and an illustrative cost-benefit analysis. We focus on assessing a subset of the engine NO X emissions certification stringency options considered at the eighth meeting of the International Civil Aviation Organization’s Committee on Aviation Environmental Protection. The FAA Aviation environmental Portfolio Management Tool (APMT) is employed to conduct the policy assessments. We show that different conclusions may be drawn about the same policy options depending on whether benefits and interdependencies are estimated in terms of health and welfare impacts versus changes in NO X emissions inventories as is the typical practice. We also show that these conclusions are sensitive to a variety of modeling uncertainties. While our more comprehensive analysis makes the best policy option less clear, it represents a more accurate characterization of the scientific and economic uncertainties underlying impacts and the policy choices.

  6. Critical market crashes

    Science.gov (United States)

    Sornette, D.

    2003-04-01

    This review presents a general theory of financial crashes and of stock market instabilities that his co-workers and the author have developed over the past seven years. We start by discussing the limitation of standard analyses for characterizing how crashes are special. The study of the frequency distribution of drawdowns, or runs of successive losses shows that large financial crashes are “outliers”: they form a class of their own as can be seen from their statistical signatures. If large financial crashes are “outliers”, they are special and thus require a special explanation, a specific model, a theory of their own. In addition, their special properties may perhaps be used for their prediction. The main mechanisms leading to positive feedbacks, i.e., self-reinforcement, such as imitative behavior and herding between investors are reviewed with many references provided to the relevant literature outside the narrow confine of Physics. Positive feedbacks provide the fuel for the development of speculative bubbles, preparing the instability for a major crash. We demonstrate several detailed mathematical models of speculative bubbles and crashes. A first model posits that the crash hazard drives the market price. The crash hazard may sky-rocket at some times due to the collective behavior of “noise traders”, those who act on little information, even if they think they “know”. A second version inverses the logic and posits that prices drive the crash hazard. Prices may skyrocket at some times again due to the speculative or imitative behavior of investors. According the rational expectation model, this entails automatically a corresponding increase of the probability for a crash. We also review two other models including the competition between imitation and contrarian behavior and between value investors and technical analysts. The most important message is the discovery of robust and universal signatures of the approach to crashes. These precursory

  7. Driving cessation and self-reported car crashes in older drivers: the impact of cognitive impairment and dementia in a population-based study.

    OpenAIRE

    Lafont, Sylviane; Laumon, Bernard; Helmer, Catherine; Dartigues, Jean-François; Fabrigoule, Colette

    2008-01-01

    International audience The complexity of driving activity has incited numerous developed countries to initiate evaluative procedures in elderly people, varying according to first evaluation age, frequency, and screening tools. The objective of this paper is to improve the knowledge of the driving cessation process regarding factors associated with crash involvement. Driving cessation and self-reported crashes during the past 5 years were analyzed with multivariate models, in a cross-sectio...

  8. Crash protection of stock car racing drivers--application of biomechanical analysis of Indy car crash research.

    Science.gov (United States)

    Melvin, John W; Begeman, Paul C; Faller, Ronald K; Sicking, Dean L; McClellan, Scott B; Maynard, Edwin; Donegan, Michael W; Mallott, Annette M; Gideon, Thomas W

    2006-11-01

    Biomechanical analysis of Indy car crashes using on-board impact recorders (Melvin et al. 1998, Melvin et al. 2001) indicates that Indy car driver protection in high-energy crashes can be achieved in frontal, side, and rear crashes with severities in the range of 100 to 135 G peak deceleration and velocity changes in the range of 50 to 70 mph. These crashes were predominantly single-car impacts with the rigid concrete walls of oval tracks. This impressive level of protection was found to be due to the unique combination of a very supportive and tight-fitting cockpit-seating package, a six-point belt restraint system, and effective head padding with an extremely strong chassis that defines the seat and cockpit of a modern Indy car. In 2000 and 2001, a series of fatal crashes in stock car racing created great concern for improving the crash protection for drivers in those racecars. Unlike the Indy car, the typical racing stock car features a more spacious driver cockpit due to its resemblance to the shape of a passenger car. The typical racing seat used in stock cars did not have the same configuration or support characteristics of the Indy car seat, and five-point belt restraints were used. The tubular steel space frame chassis of a stock car also differs from an Indy car's composite chassis structure in both form and mechanical behavior. This paper describes the application of results of the biomechanical analysis of the Indy car crash studies to the unique requirements of stock car racing driver crash protection. Sled test and full-scale crash test data using both Hybrid III frontal crash anthropomorphic test devices (ATDs) and BioSID side crash ATDs for the purpose of evaluating countermeasures involving restraint systems, seats and head/neck restraints has been instrumental in guiding these developments. In addition, the development of deformable walls for oval tracks (the SAFER Barrier) is described as an adjunct to improved occupant restraint through control

  9. Gas and Particulate Aircraft Emissions Measurements: Impacts on local air quality.

    Science.gov (United States)

    Jayne, J. T.; Onasch, T.; Northway, M.; Canagaratna, M.; Worsnop, D.; Timko, M.; Wood, E.; Miake-Lye, R.; Herndon, S.; Knighton, B.; Whitefield, P.; Hagen, D.; Lobo, P.; Anderson, B.

    2007-12-01

    Air travel and freight shipping by air are becoming increasingly important and are expected to continue to expand. The resulting increases in the local concentrations of pollutants, including particulate matter (PM), volatile organic compounds (VOCs), and nitrogen oxides (NOX), can have negative impacts on regional air quality, human health and can impact climate change. In order to construct valid emission inventories, accurate measurements of aircraft emissions are needed. These measurements must be done both at the engine exit plane (certification) and downwind following the rapid cooling, dilution and initial atmospheric processing of the exhaust plume. We present here results from multiple field experiments which include the Experiment to Characterize Volatile Aerosol and Trace Species Emissions (EXCAVATE) and the four Aircraft Particle Emissions eXperiments (APEX- 1/Atlanta/2/3) which characterized gas and particle emissions from both stationary or in-use aircraft. Emission indices (EIs) for NOx and VOCs and for particle number concentration, refractory PM (black carbon soot) and volatile PM (primarily sulfate and organic) particles are reported. Measurements were made at the engine exit plane and at several downstream locations (10 and 30 meters) for a number of different engine types and engine thrust settings. A significant fraction of organic particle mass is composed of low volatility oil-related compounds and is not combustion related, potentially emitted by vents or heated surfaces within aircraft engines. Advected plumes measurements from in-use aircraft show that the practice of reduced thrust take-offs has a significant effect on total NOx and soot emitted in the vicinity of the airport. The measurements reported here represent a first observation of this effect and new insights have been gained with respect to the chemical processing of gases and particulates important to the urban airshed.

  10. Braking news: link between crash severity and crash avoidance maneuvers

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    This study focused on the link between crash severity and crash avoidance maneuvers. Various emergency lateral and speed control maneuvers were considered in response to different critical events that made the crash imminent. Partial proportional odds models that allowed for changes in effects...... across severity levels were estimated to accommodate the ordered-response nature of severity. The sample used for estimation consisted of data for single-vehicle crashes extracted from the General Estimates System crash database for the period from 2005 to 2009. Results showed the correlation between...... crash avoidance maneuvers and crash severity, with differences emerging for different critical events. Moreover, results showed two trends:(a) most drivers failed to act when facing critical events and (b) drivers rarely performed crash avoidance maneuvers that were correlated with a higher probability...

  11. Proceedings of impact of aircraft emissions upon the atmosphere. V. 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The study of the effect of aircraft on atmosphere is a new challenge that the scientific community has to face. This conference`s topics are various aspects of this challenge. The poster sessions of Volume 2 accompanying sessions 1 through 7 contain various aspects of aerosols, contrails, instruments, measurements, modelling, climatic impacts, projects, transport, atmospheric chemistry etc. The 49 papers of Vol.2. were indexed and abstracted individually for the Energy Database. (R.P.)

  12. Micro-physics of aircraft-generated aerosols and their potential impact on heterogeneous plume chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kaercher, B.; Luo, B.P. [Muenchen Univ., Freising (Germany). Lehrstuhl fuer Bioklimatologie und Immissionsforschung

    1997-12-31

    Answers are attempted to give to open questions concerning physico-chemical processes in near-field aircraft plumes, with emphasis on their potential impact on subsequent heterogeneous chemistry. Research issues concerning the nucleation of aerosols and their interactions among themselves and with exhaust gases are summarized. Microphysical properties of contrail ice particles, formation of liquid ternary mixtures, and nucleation of nitric acid trihydrate particles in contrails are examined and possible implications for heterogeneous plume chemistry are discussed. (author) 19 refs.

  13. Reaction-time relationship and structural design of reinforced concrete slabs and shells for aircraft impact

    International Nuclear Information System (INIS)

    The reaction-time relationship for a deformable aircraft impacting on a rigid wall is derived. The resulting expression is compared to the expression presently in the literature and it is found that this new expression gives peak values of the reaction significantly less (approximately 40%) than the presently used expression The reaction-time relationships for aircraft typical of a business jet, fighter-bomber and jet transport are evaluated. The peak value of the reaction-time relationship is very sensitive to changes in the initial impact velocity and the peak value of the weight distribution and relatively insensitive to changes in the crushing strength distribution and modifications of the weight distribution that do not change the peak value of the weight distribution. A structure is required to prevent penetration by any part of the aircraft. Severe damage is to be expected. The structure will be considered to have retained its structural integrity, if it does not collapse. It is assumed that only a region of the slab or shell in the near vicinity of the region of impact participates in energy absorption. For slabs, the maximum resistance is given as the collapse load for a concentrated load. For shells with large dimensions, the same value is used as a conservative estimate. The dynamic effect are estimated using the method of Biggs. The ratio of the peak allowable force to the maximum resistance (F/R) is greater than unity as long as the participating material has a radius equal to or greater than that of the fuselage of the impacting aircraft. For any particular radius of participating material, the increase in (F/R) as a function of allowable ductility ratio is also shown. The punching shear capacity is determined by taking account of the reinforcement steel and yield line pattern

  14. Estimating likelihood of future crashes for crash-prone drivers

    Directory of Open Access Journals (Sweden)

    Subasish Das

    2015-06-01

    Full Text Available At-fault crash-prone drivers are usually considered as the high risk group for possible future incidents or crashes. In Louisiana, 34% of crashes are repeatedly committed by the at-fault crash-prone drivers who represent only 5% of the total licensed drivers in the state. This research has conducted an exploratory data analysis based on the driver faultiness and proneness. The objective of this study is to develop a crash prediction model to estimate the likelihood of future crashes for the at-fault drivers. The logistic regression method is used by employing eight years' traffic crash data (2004–2011 in Louisiana. Crash predictors such as the driver's crash involvement, crash and road characteristics, human factors, collision type, and environmental factors are considered in the model. The at-fault and not-at-fault status of the crashes are used as the response variable. The developed model has identified a few important variables, and is used to correctly classify at-fault crashes up to 62.40% with a specificity of 77.25%. This model can identify as many as 62.40% of the crash incidence of at-fault drivers in the upcoming year. Traffic agencies can use the model for monitoring the performance of an at-fault crash-prone drivers and making roadway improvements meant to reduce crash proneness. From the findings, it is recommended that crash-prone drivers should be targeted for special safety programs regularly through education and regulations.

  15. Aircraft emission impacts in a neighborhood adjacent to a general aviation airport in southern California.

    Science.gov (United States)

    Hu, Shishan; Fruin, Scott; Kozawa, Kathleen; Mara, Steve; Winer, Arthur M; Paulson, Suzanne E

    2009-11-01

    Real time air pollutant concentrations were measured downwind of Santa Monica Airport (SMA), using an electric vehicle mobile platform equipped with fast response instruments in spring and summer of 2008. SMA is a general aviation airport operated for private aircraft and corporate jets in Los Angeles County, California. An impact area of elevated ultrafine particle (UFP) concentrations was observed extending beyond 660 m downwind and 250 m perpendicular to the wind on the downwind side of SMA. Aircraft operations resulted in average UFP concentrations elevated by factors of 10 and 2.5 at 100 and 660 m downwind, respectively, over background levels. The long downwind impact distance (i.e., compared to nearby freeways at the same time of day) is likely primarily due to the large volumes of aircraft emissions containing higher initial concentrations of UFP than on-road vehicles. Aircraft did not appreciably elevate average levels of black carbon (BC), particle-bound polycyclic aromatic hydrocarbons (PB-PAH), although spikes in concentration of these pollutants were observed associated with jet takeoffs. Jet departures resulted in peak 60-s average concentrations of up to 2.2 x 10(6) cm(-3), 440 ng m(-3), and 30 microg m(-3) for UFP, PB-PAH, and BC, respectively, 100 m downwind of the takeoff area. These peak levels were elevated by factors of 440, 90, and 100 compared to background concentrations. Peak UFP concentrations were reasonably correlated (r(2) = 0.62) with fuel consumption rates associated with aircraft departures, estimated from aircraft weights and acceleration rates. UFP concentrations remained elevated for extended periods associated particularly with jet departures, but also with jet taxi and idle, and operations of propeller aircraft. UFP measured downwind of SMA had a median mode of about 11 nm (electric mobility diameter), which was about half of the 22 nm median mode associated with UFP from heavy duty diesel trucks. The observation of highly

  16. Some vortical-flow flight experiments on slender aircraft that impacted the advancement of aeronautics

    Science.gov (United States)

    Lamar, John E.

    2009-08-01

    This paper highlights the three aerodynamic pillars of aeronautics; namely, theory/CFD, wind-tunnel experiments and flight tests, and notes that at any given time these three are not necessarily at the same level of maturity. After an initial history of these three pillars, the focus narrows to a brief history of some vortical-flow flight experiments on slender aircraft that have impacted the advancement of aeronautics in recent decades. They include the F-106, Concorde, SR-71, light-weight fighters (F-16, F/A-18), and F-16XL. These aircraft share in common the utilization of vortical flow and have flown at transonic speeds during a part of the flight envelope. Due to the vast amount of information from flight and CFD that has recently become available for the F-16XL, this aircraft is highlighted and its results detailed. Lastly, it is interesting to note that, though complicated, vortical flows over the F-16XL aircraft at subsonic speeds can be reliably and generally well-predicted with the current CFD flow solvers. However, these solvers still have some problems in matching flight pressure data at transonic speeds. That this problem has been highlighted is both an advancement in aeronautics and a tempting prize to those who would seek its solution.

  17. Modeling the impact of improved aircraft operations technologies on the environment and airline behavior

    Science.gov (United States)

    Foley, Ryan Patrick

    The overall goal of this thesis is to determine if improved operations technologies are economically viable for US airlines, and to determine the level of environmental benefits available from such technologies. Though these operational changes are being implemented primarily with the reduction of delay and improvement of throughput in mind, economic factors will drive the rate of airline adoption. In addition, the increased awareness of environmental impacts makes these effects an important aspect of decision-making. Understanding this relationship may help policymakers make decisions regarding implementation of these advanced technologies at airports, and help airlines determine appropriate levels of support to provide for these new technologies. In order to do so, the author models the behavior of a large, profit-seeking airline in response to the introduction of advanced equipage allowing improved operations procedures. The airline response included changes in deployed fleet, assignment of aircraft to routes, and acquisition of new aircraft. From these responses, changes in total fleet-level CO2 emissions and airline profit were tallied. As awareness of the environmental impact of aircraft emissions has grown, several agencies (ICAO, NASA) have moved to place goals for emissions reduction. NASA, in particular, has set goals for emissions reduction through several areas of aircraft technology. Among these are "Operational Improvements," technologies available in the short-term through avionics and airport system upgrades. The studies in this thesis make use of the Fleet-Level Environmental Evaluation Tool (FLEET), a simulation tool developed by Purdue University in support of a NASA-sponsored research effort. This tool models the behavior of a large, profit-seeking airline through an allocation problem. The problem is contained within a systems dynamics type approach that allows feedback between passenger demand, ticket price, and the airline fleet composition

  18. Road crash costs.

    OpenAIRE

    2010-01-01

    Road crashes result in all kinds of social costs, such as medical costs, production loss, human losses, property damage, settlement costs and costs due to congestion. Studies into road crash costs and their trends are carried out quite regularly. In 2009, the costs amounted to € 12.5 billion, or 2.2% of the Gross Domestic Product (GDP). Insight into these costs is used for policy preparation and evaluation, and makes it possible to compare them with costs in other areas. Another important app...

  19. The Crash of '87

    OpenAIRE

    Freeman, Alan

    1988-01-01

    This article was published in a Capital and Class symposium on the 1987 crash. Its analysis retains its full force in 2009. It compared the 1987 and the 1929 crash, and explored the historical similarities between the long US postwar decline and the UK’s, from the mid-nineteenth century. It situated both in a rigorous value-theoretic framework rooted in Marx’s concept of superprofit. It was the author’s first such published attempt. It combined, critically, Kondratieff’s account of long w...

  20. Biomechanically based design and performance targets for a 3-year old child crash dummy for front and side impact

    NARCIS (Netherlands)

    Ratingen, M.R. van; Twisk, D.; Schrooten, M.; Barnes, A.; Platten, G.

    1997-01-01

    The Q-series of child dummies is a new family of advanced child dummies covering the complete child population up to 12 years. The 'Q-series' design is not only advanced in terms of its biomechanical basis, it is also developed to be used in both front and side impact making it the first 'multi-dire

  1. Time-Varying Crash Risk

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunoua, Bruno; Jeon, Yoontae;

    We estimate a continuous-time model with stochastic volatility and dynamic crash probability for the S&P 500 index and find that market illiquidity dominates other factors in explaining the stock market crash risk. While the crash probability is time-varying, its dynamic depends only weakly on...

  2. A critical reappraisal of nuclear power plant safety against accidental aircraft impact

    International Nuclear Information System (INIS)

    The overall problem of nuclear power plant safety against an accidental aircraft impact is discussed in relation with its structural analysis and design. Associated risks, such as fire, which is a potential source of damage for buildings and other structures, are not considered. The paper is divided in two parts. In part I different approaches used for determining the reaction-time curve are discussed. The influence on the results of target motions is examined next. It is shown that for the evaluation of structural response an aircraft-structure interaction analysis is usually an unnecessary refinement, 'mean' reaction-time and impact area-time curves being sufficient to define the excitation. Preliminary results for oblique impact are also given. Since the conditional probability of a normal impact is very small, the consideration of oblique impact may become acceptable in future design criteria. In part II, available solutions for the resulting structural dynamic problem are reviewed. The feasibility of resorting to a static analysis is also discussed. Present practices to evaluate floor response spectra are reviewed next. The short-comings of the 'deterministic' approach are pointed out. It is proposed to define the excitation as a mean plus a fluctuating force. The latter is treated as a nonstationary random process and the problem solved by numerical integration in the time domain. Although such solutions get prohibitively expensive when the number of degrees of freedom becomes large, results obtained for simple models may help to clarify which are the important variables of the problem. (orig.)

  3. A methodology to enable rapid evaluation of aviation environmental impacts and aircraft technologies

    Science.gov (United States)

    Becker, Keith Frederick

    Commercial aviation has become an integral part of modern society and enables unprecedented global connectivity by increasing rapid business, cultural, and personal connectivity. In the decades following World War II, passenger travel through commercial aviation quickly grew at a rate of roughly 8% per year globally. The FAA's most recent Terminal Area Forecast predicts growth to continue at a rate of 2.5% domestically, and the market outlooks produced by Airbus and Boeing generally predict growth to continue at a rate of 5% per year globally over the next several decades, which translates into a need for up to 30,000 new aircraft produced by 2025. With such large numbers of new aircraft potentially entering service, any negative consequences of commercial aviation must undergo examination and mitigation by governing bodies so that growth may still be achieved. Options to simultaneously grow while reducing environmental impact include evolution of the commercial fleet through changes in operations, aircraft mix, and technology adoption. Methods to rapidly evaluate fleet environmental metrics are needed to enable decision makers to quickly compare the impact of different scenarios and weigh the impact of multiple policy options. As the fleet evolves, interdependencies may emerge in the form of tradeoffs between improvements in different environmental metrics as new technologies are brought into service. In order to include the impacts of these interdependencies on fleet evolution, physics-based modeling is required at the appropriate level of fidelity. Evaluation of environmental metrics in a physics-based manner can be done at the individual aircraft level, but will then not capture aggregate fleet metrics. Contrastingly, evaluation of environmental metrics at the fleet level is already being done for aircraft in the commercial fleet, but current tools and approaches require enhancement because they currently capture technology implementation through post

  4. Hazards from aircraft

    International Nuclear Information System (INIS)

    The siting of nuclear power plants has created innumerable environmental concerns. Among the effects of the ''man-made environment'' one of increasing importance in recent nuclear plant siting hazards analysis has been the concern about aircraft hazards to the nuclear plant. These hazards are of concern because of the possibility that an aircraft may have a malfunction and crash either near the plant or directly into it. Such a crash could be postulated to result, because of missile and/or fire effects, in radioactive releases which would endanger the public health and safety. The majority of studies related to hazards from air traffic have been concerned with the determination of the probability associated with an aircraft striking vulnerable portions of a given plant. Other studies have focused on the structural response to such a strike. This work focuses on the problem of strike probability. 13 references

  5. Effects of reinforcement ratio and arrangement on the structural behavior of a nuclear building under aircraft impact

    Energy Technology Data Exchange (ETDEWEB)

    Thai, Duc-Kien; Kim, Seung-Eock, E-mail: sekim@sejong.ac.kr; Lee, Hyuk-Kee

    2014-09-15

    Highlights: • Numerical analysis of RC nuclear building model under aircraft impact was conducted. • The analysis result shows similar behavior as compared to the Riera function. • The effects of reinforcement ratio and arrangement were enumerated. • The appropriate number of layer of longitudinal rebar was recommended. - Abstract: This study presents the effectiveness of the rebar ratio and the arrangement of reinforced concrete (RC) structures on the structural behavior of nuclear buildings under aircraft impact using a finite element (FE) approach. A simplified model of a fictitious nuclear building using RC structures was fully modeled. The aircraft model of a Boeing 767-400 was used for impact simulation and was developed and verified with a conventional impact force–time history curve. The IRIS Punching test was used to validate the damage prediction capabilities of the RC wall under impact loading. With regard to the different rebar ratios and rebar arrangements of a nuclear RC building, the structural behavior of a building under aircraft impact was investigated. The structural behavior investigated included plastic deformation, displacement, energy dissipation, perforation/penetration depth and scabbing area. The results showed that the rebar ratio has a significant effect on withstanding aircraft impact and reducing local damage. With four layers of rebar, the RC wall absorbed and dissipated the impact energy more than once with only two layers of rebar for the same rebar ratio.

  6. Effects of reinforcement ratio and arrangement on the structural behavior of a nuclear building under aircraft impact

    International Nuclear Information System (INIS)

    Highlights: • Numerical analysis of RC nuclear building model under aircraft impact was conducted. • The analysis result shows similar behavior as compared to the Riera function. • The effects of reinforcement ratio and arrangement were enumerated. • The appropriate number of layer of longitudinal rebar was recommended. - Abstract: This study presents the effectiveness of the rebar ratio and the arrangement of reinforced concrete (RC) structures on the structural behavior of nuclear buildings under aircraft impact using a finite element (FE) approach. A simplified model of a fictitious nuclear building using RC structures was fully modeled. The aircraft model of a Boeing 767-400 was used for impact simulation and was developed and verified with a conventional impact force–time history curve. The IRIS Punching test was used to validate the damage prediction capabilities of the RC wall under impact loading. With regard to the different rebar ratios and rebar arrangements of a nuclear RC building, the structural behavior of a building under aircraft impact was investigated. The structural behavior investigated included plastic deformation, displacement, energy dissipation, perforation/penetration depth and scabbing area. The results showed that the rebar ratio has a significant effect on withstanding aircraft impact and reducing local damage. With four layers of rebar, the RC wall absorbed and dissipated the impact energy more than once with only two layers of rebar for the same rebar ratio

  7. Blind spot crashes.

    NARCIS (Netherlands)

    2009-01-01

    Crashes involving lorries turning right and cyclists going straight ahead usually have very serious consequences for the cyclist. The cyclist, who has right of way, is often overlooked by the lorry driver. For his part, the cyclist is often unaware that the lorry driver has not seen him or that the

  8. Airplane crash simulations

    International Nuclear Information System (INIS)

    Impact loads are considered in nuclear facility design as the result of the loading effects of certain design basis accidents and design basis threats made up of natural as well as man-made hazards. Also, beyond design basis accidents and threats are considered. Typical missiles include objects caused by tornado winds, aircrafts, war or terrorist activities, dropped objects, turbine fragments and other missiles resulting from failure of rotating equipment and whipping pipes and other objects of failure of pressurized fluid systems. The aim of the work is to study the potential of tools for numerical simulations to study the local load effects of airplane missiles impacting concrete structures. Two of the leading commercial computer codes for analysis of highly dynamic events, ABAQUS/Explicit and AUTODYN, have been evaluated. Numerical simulations have been carried out for rigid as well as deformable missiles with the characteristics of airplane engines. The analysis results have been compared with test results from a test program performed in the USA at Sandia National Laboratory and in Japan at Kobori Research Complex and Central Research Institute of the Electric Power industry. Finally, numerical simulations of a large passenger airliner impacting a reactor containment has been carried out using the analysis methodology developed. (author)

  9. Innovative Anti Crash Absorber for a Crashworthy Landing Gear

    Science.gov (United States)

    Guida, Michele; Marulo, Francesco; Montesarchio, Bruno; Bruno, Massimiliano

    2014-06-01

    This paper defines an innovative concept to anti-crash absorber in composite material to be integrated on the landing gear as an energy-absorbing device in crash conditions to absorb the impact energy. A composite cylinder tube in carbon fiber material is installed coaxially to the shock absorber cylinder and, in an emergency landing gear condition, collapses in order to enhance the energy absorption performance of the landing system. This mechanism has been developed as an alternative solution to a high-pressure chamber installed on the Agusta A129 CBT helicopter, which can be considered dangerous when the helicopter operates in hard and/or crash landing. The characteristics of the anti-crash device are presented and the structural layout of a crashworthy landing gear adopting the developed additional energy absorbing stage is outlined. Experimental and numerical results relevant to the material characterization and the force peaks evaluation of the system development are reported. The anti-crash prototype was designed, analysed, optimized, made and finally the potential performances of a landing gear with the additional anti-crash absorber system are tested by drop test and then correlated with a similar test without the anti-crash system, showing that appreciable energy absorbing capabilities and efficiencies can be obtained in crash conditions.

  10. Crash Risk Reduction at Signalized Intersections Using Longitudinal Data

    OpenAIRE

    Mark L. Burkey; Obeng, Kofi

    2005-01-01

    This study extends the previous work of Burkey and Obeng (2004) that examined the impact of red light cameras on the type and severity of crashes at signalized intersections in Greensboro, NC. The extension takes the following form. First, we extend the data to cover 57 months, and to include demographics, technology variables, the condition of a driver at the time of the crash, vehicle characteristics, land use and visual obstruction. Second, instead of examining the impact of re...

  11. Injury Patterns in Side Pole Crashes

    OpenAIRE

    Pintar, Frank A.; Maiman, Dennis J.; Yoganandan, Narayan

    2007-01-01

    Side impact pole/tree crashes can have devastating consequences. A series of 53 CIREN cases of narrow-object side impacts were analyzed. Twenty-seven of 53 had serious chest injury and 27 had serious head injury. Unilateral chest trauma led to the examination of residual crush pattern that often demonstrated oblique door intrusion into the occupant thorax space. It was hypothesized that unilateral chest trauma was caused by antero-lateral chest loading. This hypothesis was evaluated by conduc...

  12. Local damage to Ultra High Performance Concrete structures caused by an impact of aircraft engine missiles

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, Werner [Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institute, Eckerstrasse 4, D-79104 Freiburg (Germany); Noeldgen, Markus, E-mail: mnoeldgen@schuessler-plan.d [Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institute, Eckerstrasse 4, D-79104 Freiburg (Germany); Schuessler-Plan Engineering Ltd., St.-Franziskus-Str. 148, D-40470 Duesseldorf (Germany); Strassburger, Elmar; Thoma, Klaus [Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institute, Eckerstrasse 4, D-79104 Freiburg (Germany); Fehling, Ekkehard [University of Kassel, Chair of Structural Concrete, Kurt-Wolters Str. 3, D-34109 Kassel (Germany)

    2010-10-15

    Research highlights: {yields} Experimental series on UHPC panels subjected to aircraft engine impact. {yields} Improved ballistic limit of fiber reinforced UHPC in comparison to conventional R/C. {yields} Detailed investigation of failure mechanisms of fiber reinforced UHPC panel. - Abstract: The impact of an aircraft engine missile causes high stresses, deformations and a severe local damage to conventional reinforced concrete. As a consequence the design of R/C protective structural elements results in components with rather large dimensions. Fiber reinforced Ultra High Performance Concrete (UHPC) is a concrete based material which combines ultra high strength, high packing density and an improved ductility with a significantly increased energy dissipation capacity due to the addition of fiber reinforcement. With those attributes the material is potentially suitable for improved protective structural elements with a reduced need for material resources. The presented paper reports on an experimental series of scaled aircraft engine impact tests with reinforced UHPC panels. The investigations are focused on the material behavior and the damage intensity in comparison to conventional concrete. The fundamental work of is taken as reference for the evaluation of the results. The impactor model of a Phantom F4 GE-J79 engine developed and validated by Sugano et al. is used as defined in the original work. In order to achieve best comparability, the experimental configuration and method are adapted for the UHPC experiments. With 'penetration', 'scabbing' and 'perforation' all relevant damage modes defined in are investigated so that a full set of results are provided for a representative UHPC structural configuration.

  13. Local damage to Ultra High Performance Concrete structures caused by an impact of aircraft engine missiles

    International Nuclear Information System (INIS)

    Research highlights: → Experimental series on UHPC panels subjected to aircraft engine impact. → Improved ballistic limit of fiber reinforced UHPC in comparison to conventional R/C. → Detailed investigation of failure mechanisms of fiber reinforced UHPC panel. - Abstract: The impact of an aircraft engine missile causes high stresses, deformations and a severe local damage to conventional reinforced concrete. As a consequence the design of R/C protective structural elements results in components with rather large dimensions. Fiber reinforced Ultra High Performance Concrete (UHPC) is a concrete based material which combines ultra high strength, high packing density and an improved ductility with a significantly increased energy dissipation capacity due to the addition of fiber reinforcement. With those attributes the material is potentially suitable for improved protective structural elements with a reduced need for material resources. The presented paper reports on an experimental series of scaled aircraft engine impact tests with reinforced UHPC panels. The investigations are focused on the material behavior and the damage intensity in comparison to conventional concrete. The fundamental work of is taken as reference for the evaluation of the results. The impactor model of a Phantom F4 GE-J79 engine developed and validated by Sugano et al. is used as defined in the original work. In order to achieve best comparability, the experimental configuration and method are adapted for the UHPC experiments. With 'penetration', 'scabbing' and 'perforation' all relevant damage modes defined in are investigated so that a full set of results are provided for a representative UHPC structural configuration.

  14. Aircraft Measurements of Saharan dust properties and impact of atmospheric transport during Fennec

    Science.gov (United States)

    Ryder, Claire; Highwood, Ellie; Rosenberg, Phil; Trembath, Jamie; Brooke, Jennifer; Bart, Mark; Dean, Angela; Dorsey, James; Crosier, Jonny; McQuaid, Jim; Brindley, Helen; Banks, James; Marsham, John; Sodemann, Harald; Washington, Richard

    2013-04-01

    Measurements of Saharan dust from recent airborne campaigns have found variations in size distributions and optical properties across Saharan and sub-Saharan Africa. These variations have an impact on radiation and thus weather and climate, and are important to characterise and understand, in particular, to understand how they vary with time after dust uplift, transport, and height in the atmosphere. New in-situ aircraft measurements from the Fennec 2011 aircraft campaign over a remote part of the Sahara Desert and the Atlantic Ocean will be presented and compared to previous airborne measurements. Size distributions extending to 300 μm will be shown, representing measurements extending further into the coarse mode than previously published for Saharan dust. The dust sampled by the aircraft covered a wide variety of loadings, dust source regions (Mali, Mauritania and Algeria) and dust ages (from fresh uplift to several days old). A significant coarse mode was present in the size distribution measurements with effective diameter up to 23 μm, and the mean size distribution showed greater concentrations of coarse mode than previous aircraft measurements. Single scattering albedo (SSA) values at 550nm calculated from these size distributions revealed high absorption from 0.77 to 0.95, with a mean of 0.85. Directly measured SSA values were higher (0.91 to 0.99) but new instrumentation revealed that these direct measurements, behind Rosemount inlets, overestimate the SSA by 0.02 to 0.20 depending on the concentration of coarse particles present. This is caused by inlet inefficiencies and pipe losses. Previous measurements of SSA from aircraft measurements may also have been overestimates for this reason. This has a significant impact on atmospheric heating rates. The largest dust particles were encountered closest to the ground, and were most abundant in cases where dust was freshly uplifted. Number concentration, mass loading and extinction coefficient showed inverse

  15. Resistance ability evaluation of the CANDU-6 containment subjected to aircraft impact forces

    International Nuclear Information System (INIS)

    In this study, the dynamic non-linear analysis for CANDU-type containment is conducted to examine the ultimate capacity under aircraft impact force by using program ADINA. For the case of the perimeter wall of a cylindrical containment, the effective reinforcement ratio can be easily specified by the constant cross-sectional area of the truss element. However, the constant cross-sectional area of the truss element cannot reflect the effect of reinforcement variation along the meridional direction at the dome of the structure. Due to the limitation of the model, the premature yielding of the reinforcement or tendon and irregular deformation at the dome have been reported. In this paper, the modeling method handling the reinforcement variation along the meridional direction at the dome of the structure is developed. The dynamic analysis gives the result that the structural damage due to concrete crushing and steel yielding is shown when an aircraft impacts against the apex place of upper dome of containment, but no structural failure in other impact places of containment

  16. A systematic rationale for defining the significance of aircraft noise impacts.

    Science.gov (United States)

    Fidell, Sanford; Mestre, Vincent; Schomer, Paul; Horonjeff, Richard; Reid, Tim

    2014-09-01

    Regulatory agencies often define strict, decibel-denominated thresholds of significance of noise impacts to protect some fraction of the residential population from exposure to highly annoying noise. Definitions of the "significance" of aircraft noise impacts and recommendations of land use "compatibility," however, typically lack detailed, systematic rationales. Instead, the definitions are justified by reference to decades-old policies that were adopted without benefit of modern understandings of noise-induced annoyance, by appeals to authority, and by generic citations of non-peer reviewed documents. Although regulatory policy decisions may properly take into consideration political and economic consequences, aspects of them are amenable to logical formalization. In particular, advances in understanding of community reaction to transportation noise now permit a systematic rationale for aircraft noise regulation. The current analyses show how regulatory policy positions can be derived from two parameters: (1) the minimal percentage of the population of a nominally average community to be protected from exposure to highly annoying noise; and (2) the percentage of all communities to which this degree of protection is intended to apply. Together with a reliable dosage-response relationship, these two parameters permit quantitatively justifiable definitions of significant noise impact. PMID:25190388

  17. Collection and valuation of numerical models with the aim to investigate the impact of aircraft emissions

    International Nuclear Information System (INIS)

    Numerical models which are used to simulate the dynamics and chemistry of the Earth atmosphere are an important expedient to improve the knowledge of atmospheric processes. With such models it is possible to investigate single effects separately and to estimate their meaning for the whole system. It is possible to make sensitivity studies as well as calculations of different scenarios. This paper aims to describe different models which are available in the present time and which can be used for investigations dealing with the impact of aircraft emission on the Earth climate. Actual deficits of the modelling of atmospheric processes are discussed and the subsequent conclusions are presented. (orig.) 49 refs

  18. Assessment of dynamic effects on aircraft design loads: The landing impact case

    Science.gov (United States)

    Bronstein, Michael; Feldman, Esther; Vescovini, Riccardo; Bisagni, Chiara

    2015-10-01

    This paper addresses the potential benefits due to a fully dynamic approach to determine the design loads of a mid-size business jet. The study is conducted by considering the fuselage midsection of the DAEDALOS aircraft model with landing impact conditions. The comparison is presented in terms of stress levels between the novel dynamic approach and the standard design practice based on the use of equivalent static loads. The results illustrate that a slight reduction of the load levels can be achieved, but careful modeling of the damping level is needed. Guidelines for an improved load definition are discussed, and suggestions for future research activities are provided.

  19. Numerical simulation of fuel spillage following an aircraft impact onto a nuclear power plant

    International Nuclear Information System (INIS)

    The possible consequences of fuel discharging from the tanks of an impacting aircraft is of interest in security analysis concerning nuclear power plant buildings. In the problem presented here the propagation of approximately 4.4 m3 of fuel from the fuselage tank of a Phantom F4 through the predamaged roof structure of a sensitive building is simulated by means of the fluid-dynamics code DYSMAS/E. The results of this investigation show that under worst-case conditions about 17% of the total mass of fuel may flow through the cracked structure, whereas in most cases the actual inflow will be much less. (orig.)

  20. Cost-benefit study concerning car front impact requirements to increase the crash-safety of pedestrians and cyclists : final report.

    NARCIS (Netherlands)

    Kampen, L.T.B. van

    1994-01-01

    The Dutch Ministry of Transport commissioned the SWOV Institute for Road Safety Research to carry out a cost benefit study concerning the introduction of car front-end tests. The aim of this proposed measure is to increase the crash-safety of both pedestrians and cyclists. It was decided to develop

  1. Present and future impact of aircraft, road traffic and shipping emissions on global tropospheric ozone

    Science.gov (United States)

    Koffi, B.; Szopa, S.; Cozic, A.; Hauglustaine, D.; van Velthoven, P.

    2010-12-01

    In this study, the LMDz-INCA climate-chemistry model and up-to-date global emission inventories are used to investigate the "present" (2000) and future (2050) impacts of transport emissions (road traffic, shipping and aircraft) on global tropospheric ozone. For the first time, both impacts of emissions and climate changes on transport-induced ozone are investigated. The 2000 transport emissions are shown to mainly affect ozone in the Northern Hemisphere, with a maximum increase of the tropospheric column of up to 5 DU, from the South-eastern US to Central Europe. The impact is dominated by road traffic in the middle and upper troposphere, North of 40° S, and by shipping in the northern lower troposphere, over oceanic regions. A strong reduction of road emissions and a moderate (B1 scenario) to high (A1B scenario) increase of the ship and aircraft emissions are projected by the year 2050. As a consequence, LMDz-INCA simulations predict a drastic decrease in the impact of road emissions, whereas aviation would become the major transport perturbation on tropospheric ozone, even in the case of a very optimistic aircraft mitigation scenario. The A1B emission scenario leads to an increase of the impact of transport on zonal mean ozone concentrations in 2050 by up to +30% and +50%, in the Northern and Southern Hemispheres, respectively. Despite a similar total amount of global NOx emissions by the various transport sectors compared to 2000, the overall impact on the tropospheric ozone column is increased everywhere in 2050, due to a sectoral shift in the emissions of the respective transport modes. On the opposite, the B1 mitigation scenario leads to a significant reduction (by roughly 50%) of the ozone perturbation throughout the troposphere compared to 2000. Considering climate change, and according to scenario A1B, a decrease of the O3 tropospheric burden is simulated by 2050 due to climate change (-1.2%), whereas an increase of ozone of up to 2% is calculated in the

  2. Advances in Crash Response

    Centers for Disease Control (CDC) Podcasts

    2009-06-29

    In this podcast, Dr. Richard C. Hunt, Director of CDC's Division of Injury Response, provides an overview on the benefits of using an Advanced Automatic Collision Notification system, or AACN, to help with emergency triage of people injured in vehicle crashes.  Created: 6/29/2009 by National Center for Injury Prevention and Control (NCIPC), Division of Injury Response (DIR).   Date Released: 6/29/2009.

  3. Crashes and Collateralized Lending

    OpenAIRE

    Jakub W. Jurek; Erik Stafford

    2011-01-01

    This paper develops a parsimonious static model for characterizing financing terms in collateralized lending markets. We characterize the systematic risk exposures for a variety of securities and develop a simple indifference-pricing framework to value the systematic crash risk exposure of the collateral. We then apply Modigliani and Miller's (1958) Proposition Two (MM) to split the cost of bearing this risk between the borrower and lender, resulting in a schedule of haircuts and financing ra...

  4. Impact Response Study on Covering Cap of Aircraft Big-Size Integral Fuel Tank

    Science.gov (United States)

    Wang, Fusheng; Jia, Senqing; Wang, Yi; Yue, Zhufeng

    2016-05-01

    In order to assess various design concepts and choose a kind of covering cap design scheme which can meet the requirements of airworthiness standard and ensure the safety of fuel tank. Using finite element software ANSYS/LS- DYNA, the impact process of covering cap of aircraft fuel tank by projectile were simulated, in which dynamical characteristics of simple single covering cap and gland double-layer covering cap impacted by titanium alloy projectile and rubber projectile were studied, as well as factor effects on simple single covering cap and gland double-layer covering cap under impact region, impact angle and impact energy were also studied. Though the comparison of critical damage velocity and element deleted number of the covering caps, it shows that the external covering cap has a good protection effect on internal covering cap. The regions close to boundary are vulnerable to appear impact damage with titanium alloy projectile while the regions close to center is vulnerable to occur damage with rubber projectile. Equivalent strain in covering cap is very little when impact angle is less than 15°. Element deleted number in covering cap reaches the maximum when impact angle is between 60°and 65°by titanium alloy projectile. While the bigger the impact angle and the more serious damage of the covering cap will be when rubber projectile impact composite covering cap. The energy needed for occurring damage on external covering cap and internal covering cap is less than and higher than that when single covering cap occur damage, respectively. The energy needed for complete breakdown of double-layer covering cap is much higher than that of single covering cap.

  5. Comparison of impacts of aircraft emissions within the boundary layer on the regional ozone in South Korea

    Science.gov (United States)

    Song, Sang-Keun; Shon, Zang-Ho; Kang, Yoon-Hee

    2015-09-01

    In this study, the air pollutants emitted from aircraft within the boundary layer (BL) were investigated for their impacts on the ozone (O3) concentration at and around three international airports (Incheon, RKSI; Gimpo, RKSS; and Jeju, RKPC) using the WRF-CMAQ modeling system during the summer of 2010. The analysis was performed using two sets of simulation scenarios: (1) with (i.e., TOTAL case) and (2) without aircraft emissions (i.e., BASE case). The model study suggested that aircraft emissions within the BL over the three airports can have a significant impact on the O3 (and NOx) concentrations in the source regions (the airports) and their surrounding/downwind areas. A significant negative impact of aircraft emissions on the O3 concentrations in the late afternoon (19:00 LST) was predicted near the three airports with their largest impact of -20 ppb near the RKSI at 19:00 LST. This was attributed mainly to the high NOx conditions in the VOC-limited areas and possibly in part to the rapid titration of O3 by NO around these airports. The rate of photochemical O3 destruction due to the aircraft emissions near the three airports was the most dominant contributor to the O3 levels compared to the other physical processes.

  6. Aircraft impact qualification of RBMK systems and components. Technical report. Rev. 00, May 1999

    International Nuclear Information System (INIS)

    In the present report, the problem of qualification procedures of electrical equipment with respect to the dynamic excitation subsequent to an aircraft impact (ACC) on a Nuclear Power Plant (NPP) is approached, within the context of IAEA Benchmark on vulnerability of equipment and structures of RBMK-type NPP against the aircraft impact. After a short description of the main objectives of the work and the relevant area of concern (Chapter 1), the safety related equipment more commonly installed in a NPP are grouped in few classes, according to widely accepted classification criteria and the relevant failure modes are described (Chapter 2). Taking as reference a deeply studied RBMK reactor (Ignalina NPP), an overview of its main characteristics and of the equipment ensemble housed in is given in Chapter 3. An overview of the worldwide most used qualification standards for safety related equipment for NPPs is reported in Chapter 4, and a comparison of the practices used in Europe for the qualification of safety related electrical and I and C equipment is described with special attention to seismic and impact qualification (Chapter 5). In the hypothesis that the equipment to qualify against impact excitation has been already qualified against seismic excitation, the problems relevant to the different nature of earthquake and shock phenomena are listed, together with the main criteria to implement a procedure which, based on standardized shock pulses, could be applied for ACC qualification purposes (Chapter 6). Consequently, a possible ACC qualification procedure is outlined (Chapter 7) and the interface data (data coming from numerical analysis and seismic qualification, to be used for ACC qualification purposes) are listed (Chapter 8). Finally, the main conclusions of the work are described (Chapter 9). The main references are listed in Chapter 10. (author)

  7. AP physics B crash course

    CERN Document Server

    Howell, Rebecca

    2012-01-01

    AP Physics B Crash Course - Get a Higher Advanced Placement Score in Less Time Crash Course is perfect for the time-crunched student, the last-minute studier, or anyone who wants a refresher on the subject. Our AP Physics B Crash Course gives you: Targeted, Focused Review - Study Only What You Need to Know The Crash Course is based on an in-depth analysis of the AP Physics B course description outline and actual AP test questions. It covers only the information tested on the exam, so you can make the most of your valuable study time. Our easy-to-read format covers: mechanics, kinetic theory, t

  8. Studying the effect of weather conditions on daily crash counts

    OpenAIRE

    Brijs, Tom; Karlis, Dimitris; Wets, Geert

    2007-01-01

    In previous research, significant effects of weather conditions on car crashes have been found. However, most studies use monthly or yearly data and only few studies are available analyzing the impact of weather conditions on daily car crash counts. Furthermore, the studies that are available on a daily level do not model the data in a time-series context, hereby ignoring the temporal serial correlation that may be present in the data. In this paper, we introduce an Integer Autoregressive mod...

  9. Investigating driver injury severity patterns in rollover crashes using support vector machine models.

    Science.gov (United States)

    Chen, Cong; Zhang, Guohui; Qian, Zhen; Tarefder, Rafiqul A; Tian, Zong

    2016-05-01

    Rollover crash is one of the major types of traffic crashes that induce fatal injuries. It is important to investigate the factors that affect rollover crashes and their influence on driver injury severity outcomes. This study employs support vector machine (SVM) models to investigate driver injury severity patterns in rollover crashes based on two-year crash data gathered in New Mexico. The impacts of various explanatory variables are examined in terms of crash and environmental information, vehicle features, and driver demographics and behavior characteristics. A classification and regression tree (CART) model is utilized to identify significant variables and SVM models with polynomial and Gaussian radius basis function (RBF) kernels are used for model performance evaluation. It is shown that the SVM models produce reasonable prediction performance and the polynomial kernel outperforms the Gaussian RBF kernel. Variable impact analysis reveals that factors including comfortable driving environment conditions, driver alcohol or drug involvement, seatbelt use, number of travel lanes, driver demographic features, maximum vehicle damages in crashes, crash time, and crash location are significantly associated with driver incapacitating injuries and fatalities. These findings provide insights for better understanding rollover crash causes and the impacts of various explanatory factors on driver injury severity patterns. PMID:26938584

  10. Fuel dispersal in high-speed aircraft/soil impact scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Tieszen, S.R.; Attaway, S.W. [Sandia National Labs., Albuquerque, NM (United States). Engineering Sciences Center

    1996-01-01

    The objective of this study is to determine how the jet fuel contained in aircraft wing tanks disperses on impact with a soft terrain, i.e., soils, at high impact velocities. The approach used in this study is to combine experimental and numerical methods. Tests were conducted with an approximately 1/42 linear-scale mass-model of a 1/4 span section of a C-141 wing impacting a sand/clay mixture. The test results showed that within the uncertainty of the data, the percentage of incident liquid mass remaining in the crater is the same as that qualitatively described in earlier napalm bomb development studies. Namely, the percentage of fuel in the crater ranges from near zero for grazing impacts to 25%--50% for high angles of impact. To support a weapons system safety assessment (WSSA), the data from the current study have been reduced to correlations. The numerical model used in the current study is a unique coupling of a Smooth Particle Hydrodynamics (SPH) method with the transient dynamics finite element code PRONTO. Qualitatively, the splash, erosion, and soil compression phenomena are all numerically predicted. Quantitatively, the numerical method predicted a smaller crater cross section than was observed in the tests.

  11. Fuel dispersal in high-speed aircraft/soil impact scenarios

    International Nuclear Information System (INIS)

    The objective of this study is to determine how the jet fuel contained in aircraft wing tanks disperses on impact with a soft terrain, i.e., soils, at high impact velocities. The approach used in this study is to combine experimental and numerical methods. Tests were conducted with an approximately 1/42 linear-scale mass-model of a 1/4 span section of a C-141 wing impacting a sand/clay mixture. The test results showed that within the uncertainty of the data, the percentage of incident liquid mass remaining in the crater is the same as that qualitatively described in earlier napalm bomb development studies. Namely, the percentage of fuel in the crater ranges from near zero for grazing impacts to 25%--50% for high angles of impact. To support a weapons system safety assessment (WSSA), the data from the current study have been reduced to correlations. The numerical model used in the current study is a unique coupling of a Smooth Particle Hydrodynamics (SPH) method with the transient dynamics finite element code PRONTO. Qualitatively, the splash, erosion, and soil compression phenomena are all numerically predicted. Quantitatively, the numerical method predicted a smaller crater cross section than was observed in the tests

  12. Impact of aircraft exhaust on the atmosphere. Box model studies and 3-D mesoscale numerical case studies of seasonal differences

    Energy Technology Data Exchange (ETDEWEB)

    Petry, H.; Ebel, A.; Franzkowiak, V.; Hendricks, J.; Lippert, E.; Moellhoff, M. [Koeln Univ. (Germany). Inst. fuer Geophysik und Meteorologie

    1997-12-31

    The impact of aircraft emissions released in the tropopause region on atmospheric trace gases as O{sub 3} or HNO{sub 3} is investigated by means of model studies. Special emphasis is drawn on seasonal effects. A box model is applied as well as a 3-D mesoscale chemistry transport model. These model studies show that the impact of aircraft emissions on ozone in the tropopause region is much stronger in summer than in late autumn with a difference of one order of magnitude. (author) 14 refs.

  13. Advances in Engineering Research : Volume 4, Environmental impacts of the future technologies of commercial aircraft

    OpenAIRE

    Khardi, Salah; KURNIAWAN, J

    2013-01-01

    Assessment of pollutant emissions (CO, HC and NOx) and fuel consumption of aircraft LTO cycles at Soekarno Hatta InternationalAirport is carried out for the first time. We stressed, by aircraft type, the large aircraft which represent the greatest contribution of pollutant emissions in and around this airport.Analysis is performed to precise theirmagnitude in relationship with fuel consumption. Distribution of aircraft pollutants for different operational modes (taxiing and takeoffs) is provi...

  14. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights.

    Directory of Open Access Journals (Sweden)

    Jonathan Donier

    Full Text Available Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes.

  15. Why Do Markets Crash? Bitcoin Data Offers Unprecedented Insights.

    Science.gov (United States)

    Donier, Jonathan; Bouchaud, Jean-Philippe

    2015-01-01

    Crashes have fascinated and baffled many canny observers of financial markets. In the strict orthodoxy of the efficient market theory, crashes must be due to sudden changes of the fundamental valuation of assets. However, detailed empirical studies suggest that large price jumps cannot be explained by news and are the result of endogenous feedback loops. Although plausible, a clear-cut empirical evidence for such a scenario is still lacking. Here we show how crashes are conditioned by the market liquidity, for which we propose a new measure inspired by recent theories of market impact and based on readily available, public information. Our results open the possibility of a dynamical evaluation of liquidity risk and early warning signs of market instabilities, and could lead to a quantitative description of the mechanisms leading to market crashes. PMID:26448333

  16. Crash Prediction and Risk Evaluation Based on Traffic Analysis Zones

    Directory of Open Access Journals (Sweden)

    Cuiping Zhang

    2014-01-01

    Full Text Available Traffic safety evaluation for traffic analysis zones (TAZs plays an important role in transportation safety planning and long-range transportation plan development. This paper aims to present a comprehensive analysis of zonal safety evaluation. First, several criteria are proposed to measure the crash risk at zonal level. Then these criteria are integrated into one measure-average hazard index (AHI, which is used to identify unsafe zones. In addition, the study develops a negative binomial regression model to statistically estimate significant factors for the unsafe zones. The model results indicate that the zonal crash frequency can be associated with several social-economic, demographic, and transportation system factors. The impact of these significant factors on zonal crash is also discussed. The finding of this study suggests that safety evaluation and estimation might benefit engineers and decision makers in identifying high crash locations for potential safety improvements.

  17. The impact of instructions on aircraft visual inspection performance : a first look at the overall results.

    Energy Technology Data Exchange (ETDEWEB)

    Drury, Colin G. (State University of New York at Buffalo, Buffalo, NY); Spencer, Floyd Wayne; Wenner, Caren A.

    2003-07-01

    The purpose of this study was to investigate the impact of instructions on aircraft visual inspection performance and strategy. Forty-two inspectors from industry were asked to perform inspections of six areas of a Boeing 737. Six different instruction versions were developed for each inspection task, varying in the number and type of directed inspections. The amount of time spent inspecting, the number of calls made, and the number of the feedback calls detected all varied widely across the inspectors. However, inspectors who used instructions with a higher number of directed inspections referred to the instructions more often during and after the task, and found a higher percentage of a selected set of feedback cracks than inspectors using other instruction versions. This suggests that specific instructions can help overall inspection performance, not just performance on the defects specified. Further, instructions were shown to change the way an inspector approaches a task.

  18. On the impact of aircraft emitted NO{sub x} on upper troposphere photochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Wahner, A.; Rohrer, F.; Ehhalt, D.H. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Atmosphaerische Chemie

    1997-12-31

    The enhanced nitrogen oxide concentrations influence the photochemical production of ozone as well as the steady state concentrations of hydroxyl radicals, OH, in the upper troposphere. That increase is small compared to the impact of NO{sub x} from fossil fuel combustion on boundary layer ozone. A simple quasi 2-D model was used for the latitude band 40 deg - 50 deg N to analyze the reasons for that. The model includes a simplified CH{sub 4} - CO chemistry and the salient sources of upper tropospheric NO{sub x}, namely lightning, stratospheric input, aircraft emissions and fast upward transport of surface emissions. It is shown that the maximum of net O{sub 3} production and OH concentrations occur at much lower NO{sub x} mixing ratios than in the lower troposphere. (author)

  19. Statistical modeling of total crash frequency at highway intersections

    Directory of Open Access Journals (Sweden)

    Arash M. Roshandeh

    2016-04-01

    Full Text Available Intersection-related crashes are associated with high proportion of accidents involving drivers, occupants, pedestrians, and cyclists. In general, the purpose of intersection safety analysis is to determine the impact of safety-related variables on pedestrians, cyclists and vehicles, so as to facilitate the design of effective and efficient countermeasure strategies to improve safety at intersections. This study investigates the effects of traffic, environmental, intersection geometric and pavement-related characteristics on total crash frequencies at intersections. A random-parameter Poisson model was used with crash data from 357 signalized intersections in Chicago from 2004 to 2010. The results indicate that out of the identified factors, evening peak period traffic volume, pavement condition, and unlighted intersections have the greatest effects on crash frequencies. Overall, the results seek to suggest that, in order to improve effective highway-related safety countermeasures at intersections, significant attention must be focused on ensuring that pavements are adequately maintained and intersections should be well lighted. It needs to be mentioned that, projects could be implemented at and around the study intersections during the study period (7 years, which could affect the crash frequency over the time. This is an important variable which could be a part of the future studies to investigate the impacts of safety-related works at intersections and their marginal effects on crash frequency at signalized intersections.

  20. Present and future impact of aircraft, road traffic and shipping emissions on global tropospheric ozone

    Directory of Open Access Journals (Sweden)

    B. Koffi

    2010-06-01

    Full Text Available In this study, the LMDz-INCA climate-chemistry model and up-to-date global emission inventories are used to investigate the "present" (2000 and future (2050 impacts of transport emissions (road traffic, shipping and aircraft on global tropospheric ozone. For the first time, both impacts of emissions and climate changes on transport-induced ozone are investigated. The 2000 transport emissions are shown to mainly affect ozone in the Northern Hemisphere, with a maximum increase of the tropospheric column of up to 5 DU, from the South-Eastern US to Central Europe. The impact is dominated by road traffic in the middle and upper troposphere, north of 40° S, and by shipping in the northern lower troposphere, over oceanic regions. A strong reduction of road emissions and amoderate (B1 scenario to high (A1B scenario increase of the ship and aircraft emissions are expected by the year 2050. As a consequence, LMDz-INCA simulations predict a drastic decrease in the impact of road emissions, whereas aviation would become the major transport perturbation on tropospheric ozone, even in the case of avery optimistic aircraft mitigation scenario. The A1B emission scenario leads to an increase of the impact of transport on zonal mean ozone concentrations in 2050 by up to +30% and +50%, in the Northern and Southern Hemispheres, respectively. Despite asimilar total amount of global NOx emissions by the various transport sectors compared to 2000, the overall impact on the tropospheric ozone column is increased everywhere in 2050, due to a sectoral shift in the emissions of the respective transport modes. On the opposite, the B1 mitigation scenario leads to asignificant reduction (by roughly 50% of the ozone perturbation throughout the troposphere compared to 2000.

    Considering climate change, and according to scenario A1B, a decrease of the O3 tropospheric burden is simulated by 2050 due to climate change (−1.2%, whereas an increase

  1. Some Considerations about the RIERA Approach and Missile-Structure Interaction Analysis Method in Aircraft Impact Assessment on Nuclear Power Plants

    International Nuclear Information System (INIS)

    In this paper, the classically preferred RIERA approach and the so-called missile-structure interaction (MSI) analysis methods which are indebted by the latest computing power are discussed about their inherent discrepancies. Studies on the safety assessments on the nuclear power plants against large civil aircraft crashes are ongoing actively. In this paper, the classically preferred RIERA approach and the so-called missile-structure interaction (MSI) analysis methods are discussed about their inherent discrepancies especially from the point of view energy balances. More advanced and simplified ways in the safety assessment of nuclear power plants against large civil aircrafts may be possible by understanding the inherent discrepancies of the RIERA approach method and the missile-structure interaction method and reducing the differences of structural responses

  2. Abnormal/Emergency Situations. Impact of Unmanned Aircraft Systems Emergency and Abnormal Events on the National Airspace System

    Science.gov (United States)

    2006-01-01

    Access 5 analyzed the differences between UAS and manned aircraft operations under five categories of abnormal or emergency situations: Link Failure, Lost Communications, Onboard System Failures, Control Station Failures and Abnormal Weather. These analyses were made from the vantage point of the impact that these operations have on the US air traffic control system, with recommendations for new policies and procedures included where appropriate.

  3. Validity and reliability of vehicle collis : crash pulse recorders for impact severity and injury risk assessment in real-life frontal impacts

    OpenAIRE

    Kullgren, Anders

    1998-01-01

    The general objectives of this thesis were to study the importance of valid and reliable data from real- life collisions, especially the effects of inaccurate data on analyses of eg injury risks. Furthermore an objective was to develop and validate an on-board measurement device for acceleration measurements, to be used in reconstructions of primarily frontal impacts. The final objective was to conduct a large fleet field study to evaluate parameters influencing injury risks...

  4. Simulation analysis of impact tests of steel plate reinforced concrete and reinforced concrete slabs against aircraft impact and its validation with experimental results

    International Nuclear Information System (INIS)

    Highlights: • Simulation analysis is carried out with two constitutive concrete models. • Winfrith model can better simulate nonlinear response of concrete than CSCM model. • Performance of steel plate concrete is better than reinforced concrete. • Thickness of safety related structures can be reduced by adopting steel plates. • Analysis results, mainly concrete material models should be validated. - Abstract: The steel plate reinforced concrete and reinforced concrete structures are used in nuclear power plants for protection against impact of an aircraft. In order to compare the impact resistance performance of steel plate reinforced concrete and reinforced concrete slabs panels, simulation analysis of 1/7.5 scale model impact tests is carried out by using finite element code ANSYS/LS-DYNA. The damage modes of all finite element models, velocity time history curves of the aircraft engine and damage to aircraft model are compared with the impact test results of steel plate reinforced concrete and reinforced concrete slab panels. The results indicate that finite element simulation results correlate well with the experimental results especially for constitutive winfrith concrete model. Also, the impact resistance performance of steel plate reinforced concrete slab panels is better than reinforced concrete slab panels, particularly the rear face steel plate is very effective in preventing the perforation and scabbing of concrete than conventional reinforced concrete structures. In this way, the thickness of steel plate reinforced concrete structures can be reduced in important structures like nuclear power plants against impact of aircraft. It also demonstrates the methodology to validate the analysis procedure with experimental and analytical studies. It may be effectively employed to predict the precise response of safety related structures against aircraft impact

  5. Potential impacts of CF3I on ozone as a replacement for CF3Br in aircraft applications

    Directory of Open Access Journals (Sweden)

    D. Youn

    2006-06-01

    Full Text Available Iodotrifluoromethane (CF3I has been considered to be a candidate replacement for bromotrifluoromethane (CF3Br, which is used in aircraft for fuel inerting and for fire fighting. In this study, the chemical effects of aircraft-released CF3I on atmospheric ozone were examined with the University of Illinois at Urbana-Champaign two-dimensional chemical-radiative-transport (UIUC 2-D CRT model. Using an earlier estimate of the aircraft emission profile for tank inerting in military aircraft, the resulting equivalent Ozone Depletion Potentials (ODPs for CF3I were in the range of 0.07 to 0.25. As a sensitivity study, we also analyzed CF3I emissions associated with fuel inerting if it were to occur at lower altitudes using an alternative estimate. The model calculations of resulting effects on ozone for this case gave ODPs≤0.05. Furthermore, through interactions with the National Institute of Standards and Technology (NIST, we analyzed the potential effects on ozone resulting from using CF3I in fire fighting connected with engine nacelle and auxiliary power unit applications. The scenarios evaluated using the NIST estimate suggested that the ODPs obtained by assuming aircraft flights occurring in several different latitude regions of the Northern Hemisphere are extremely low. According to the model calculation, the altitude where CF3I is released from aircraft is a dominant factor in its ozone depletion effects. On the assumption that the CF3I emission profile is representative of actual release characteristics, aircraft-released CF3I has much lower impacts on the ozone layer and can be a qualified substitute of CF3Br in engine nacelles.

  6. Impact loaded reinforced concrete structures, numerical and experimental studies

    International Nuclear Information System (INIS)

    Conclusions:In order to simulate realistically dynamic behaviour of an impact loaded reinforced concrete slab, all the material behaviour should be modelled strain rate dependent. However, in a real scale case, considering a passenger aircraft crashing to a containment building, the strain rates in reinforced concrete wall are probably lower than those observed during the impact tests. Experimental research is needed to obtain relevant data for numerical analyses. Also numerical methods and models need further development

  7. Impacts of alternative fuels in aviation on microphysical aerosol properties and predicted ice nuclei concentration at aircraft cruise altitude

    Science.gov (United States)

    Weinzierl, B.; D'Ascoli, E.; Sauer, D. N.; Kim, J.; Scheibe, M.; Schlager, H.; Moore, R.; Anderson, B. E.; Ullrich, R.; Mohler, O.; Hoose, C.

    2015-12-01

    In the past decades air traffic has been substantially growing affecting air quality and climate. According to the International Civil Aviation Authority (ICAO), in the next few years world passenger and freight traffic is expected to increase annually by 6-7% and 4-5%, respectively. One possibility to reduce aviation impacts on the atmosphere and climate might be the replacement of fossil fuels by alternative fuels. However, so far the effects of alternative fuels on particle emissions from aircraft engines and their ability to form contrails remain uncertain. To study the effects of alternative fuels on particle emissions and the formation of contrails, the Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) field experiment was conducted in California. In May 2014, the DLR Falcon 20 and the NASA HU-25 jet aircraft were instrumented with an extended aerosol and trace gas payload probing different types of fuels including JP-8 and JP-8 blended with HEFA (Hydroprocessed Esters and Fatty Acids) while the NASA DC8 aircraft acted as the source aircraft for ACCESS-2. Emission measurements were taken in the DC8 exhaust plumes at aircraft cruise level between 9-12 km altitude and at distances between 50 m and 20 km behind the DC8 engines. Here, we will present results from the ACCESS-2 aerosol measurements which show a 30-60% reduction of the non-volatile (mainly black carbon) particle number concentration in the aircraft exhaust for the HEFA-blend compared to conventional JP-8 fuel. Size-resolved particle emission indices show the largest reductions for larger particle sizes suggesting that the HEFA blend contains fewer and smaller black carbon particles. We will combine the airborne measurements with a parameterization of deposition nucleation developed during a number of ice nucleation experiments at the AIDA chamber in Karlsruhe and discuss the impact of alternative fuels on the abundance of potential ice nuclei at cruise conditions.

  8. A NASA study of the impact of technology on future sea based attack aircraft

    Science.gov (United States)

    Hahn, Andrew S.

    1992-01-01

    A conceptual aircraft design study was recently completed evaluating carrier-based, subsonic attack aircraft using contemporary and future technology assumptions. The study examined a configuration matrix that was made up of light and medium bomb loads, one and two man crews, internal and external weapons carriage, as well as conventional and flying wing planforms. Use of common technology assumptions, engine cycle simulation code, design mission, and consistent application of methods allow for direct comparison of the aircraft. This paper describes the design study ground rules and the aircraft designed. The aircraft descriptions include weights, dimensions, layout, design mission, design constraints, maneuver performance, and fallout mission performance. The strengths, and weaknesses of each aircraft are highlighted.

  9. Airplane crash modelling: assessment of the riera model

    International Nuclear Information System (INIS)

    The Riera approach is the most common method of defining a loading curve of a missile impacting a structure. After a brief reminder of the Riera assumptions (soft crash for crushed parts, instantaneous deceleration of uncrushed part due to local crushing strength of crushing part), some physical insights are developed. According to this model, the loading curve F(x, t), where the section S(x) at distance x (x=x (t)) from missile nose is under crushing, is given by the sum of a term Re(x), corresponding to the mechanical crushing strength of the section S(x), and of a term μ(x)*v(t)2, corresponding to the inertial force exerted at section S(x) by mass elements of density μ(x), whose velocity decreases from v to zero. Some analytical considerations are proposed regarding the missile motion when impacting a rigid target and its energy dissipation. Results from models of missile and target structures performed with the fast dynamic Finite Element code RADIOSS are used to assess the robustness, accuracy and limits of Riera model. Significant discrepancies between these approaches are found for commercial aircraft. Models by fast dynamic explicit code display loading curves characterised by higher and sharper peaks, whereas the velocity decrease of the uncrushed part is delayed. Riera model assumptions are therefore questioned and analysed. Those discrepancies are mainly due to higher distribution peaks of crushing strength and mass density and due to some hard inclusions in aircraft structure, like the engines and the junction of wing to fuselage. Soft impact is no longer relevant for such parts, whose action is then characterised by high peaks of short duration. When rounding the loading curve and spreading the impact area, the shear rupture is underestimated. Regarding concrete damaging, the Riera approach appears too optimistic. In order to keep the simplicity of the Riera approach and to improve its accuracy, the authors propose to evaluate the loading curve by

  10. Evaluating the Impact of Unrestricted Operation of Unmanned Aircraft Systems in the National Airspace System

    Data.gov (United States)

    National Aeronautics and Space Administration — Unmanned aircraft systems (UAS) can be used for scientific, emergency management, and defense missions, among others. The existing federal air regulations,...

  11. Crash course in readers' advisory

    CERN Document Server

    Orr, Cynthia

    2014-01-01

    One of the key services librarians provide is helping readers find books they'll enjoy. This ""crash course"" will furnish you with the basic, practical information you need to excel at readers' advisory (RA) for adults and teens.

  12. The impact of aircraft noise exposure on South African children′s reading comprehension: The moderating effect of home language

    Directory of Open Access Journals (Sweden)

    Joseph Seabi

    2012-01-01

    Full Text Available Given the limited studies conducted within the African continent, the purpose of this study was to investigate the impact of chronic aircraft noise exposure and the moderating effect of home language on the learners′ reading comprehension. The sample comprised 437 (52% senior primary learners exposed to high levels of aircraft noise (Experimental group and 337 (48% learners residing in a quieter area (Control group. Of these, 151 learners in the Experimental group spoke English as a first language (EFL and 162 spoke English as a second language (ESL. In the Control group, the numbers were similarly divided (EFL n = 191; ESL n = 156. A univariate General Linear Model was used to investigate the effects of aircraft noise exposure and language on reading comprehension, while observing for the possible impact of intellectual ability, gender, and socioeconomic status on the results. A significant difference was observed between ESL and EFL learners in favor of the latter (F 1,419 = 21.95, P =.000. In addition a substantial and significant interaction effect was found between the experimental and control groups for the two language groups. For the EFL speakers there was a strong reduction in reading comprehension in the aircraft noise group. By contrast this difference was not significant for the ESL speakers. Implications of the findings and suggestions for further research are made in the article.

  13. The impact of aircraft noise exposure on South African children's reading comprehension: the moderating effect of home language.

    Science.gov (United States)

    Seabi, Joseph; Cockcroft, Kate; Goldschagg, Paul; Greyling, Mike

    2012-01-01

    Given the limited studies conducted within the African continent, the purpose of this study was to investigate the impact of chronic aircraft noise exposure and the moderating effect of home language on the learners' reading comprehension. The sample comprised 437 (52%) senior primary learners exposed to high levels of aircraft noise (Experimental group) and 337 (48%) learners residing in a quieter area (Control group). Of these, 151 learners in the Experimental group spoke English as a first language (EFL) and 162 spoke English as a second language (ESL). In the Control group, the numbers were similarly divided (EFL n = 191; ESL n = 156). A univariate General Linear Model was used to investigate the effects of aircraft noise exposure and language on reading comprehension, while observing for the possible impact of intellectual ability, gender, and socioeconomic status on the results. A significant difference was observed between ESL and EFL learners in favor of the latter (F 1,419 = 21.95, P =.000). In addition a substantial and significant interaction effect was found between the experimental and control groups for the two language groups. For the EFL speakers there was a strong reduction in reading comprehension in the aircraft noise group. By contrast this difference was not significant for the ESL speakers. Implications of the findings and suggestions for further research are made in the article. PMID:23117540

  14. Development and use of computational techniques in Army Aviation research and development programs for crash resistant helicopter technology

    Science.gov (United States)

    Burrows, Leroy T.

    1993-08-01

    During the 1960's over 30 full-scale aircraft crash tests were conducted by the Flight Safety Foundation under contract to the Aviation Applied Technology Directorate (AATD) of the U.S. Army Aviation Systems Command (AVSCOM). The purpose of these tests were to conduct crash injury investigations that would provide a basis for the formulation of sound crash resistance design criteria for light fixed-wing and rotary wing aircraft. This resulted in the Crash Survival Design Criteria Designer's Guide which was first published in 1967 and has been revised numerous times, the last being in 1989. Full-scale aircraft crash testing is an expensive way to investigate structural deformations of occupied spaces and to determine the decelerative loadings experienced by occupants in a crash. This gave initial impetus to the U.S. Army to develop analytical methods to predict the dynamic response of aircraft structures in a crash. It was believed that such analytical tools could be very useful in the preliminary design stage of a new helicopter system which is required to demonstrate a level of crash resistance and had to be more cost effective than full-scale crash tests or numerous component design support tests. From an economic point of view, it is more efficient to optimize for the incorporation of crash resistance features early in the design stage. However, during preliminary design it is doubtful if sufficient design details, which influence the exact plastic deformation shape of structural elements, will be available. The availability of simple procedures to predict energy absorption and load-deformation characteristics will allow the designer to initiate valuable cost, weight, and geometry tradeoff studies. The development of these procedures will require some testing of typical specimens. This testing should, as a minimum, verify the validity of proposed procedures for providing pertinent nonlinear load-deformation data. It was hoped that through the use of these

  15. How Common are Noise Sources on the Crash Arc of Malaysian Flight 370

    Energy Technology Data Exchange (ETDEWEB)

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kunkle, Thomas David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stead, Richard J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-21

    Malaysian Flight 370 disappeared nearly without a trace. Besides some communication handshakes to the INMASAT satellite, the Comprehensive Test Ban Treaty monitoring system could have heard the aircraft crash into the southern Indian Ocean. One noise event from Cape Leeuwin has been suggested by Stead as the crash and occurs within the crash location suggested by Kunkle at el. We analyze the hydrophone data from Cape Leeuwin to understand how common such noise events are on the arc of possible locations where Malaysian Flight 370 might have crashed. Few other noise sources were found on the arc. The noise event found by Stead is the strongest. No noise events are seen within the Australian Transportation Safety Board (ATSB) new search location until the 10th strongest event, an event which is very close to the noise level.

  16. Projected Demand and Potential Impacts to the National Airspace System of Autonomous, Electric, On-Demand Small Aircraft

    Science.gov (United States)

    Smith, Jeremy C.; Viken, Jeffrey K.; Guerreiro, Nelson M.; Dollyhigh, Samuel M.; Fenbert, James W.; Hartman, Christopher L.; Kwa, Teck-Seng; Moore, Mark D.

    2012-01-01

    Electric propulsion and autonomy are technology frontiers that offer tremendous potential to achieve low operating costs for small-aircraft. Such technologies enable simple and safe to operate vehicles that could dramatically improve regional transportation accessibility and speed through point-to-point operations. This analysis develops an understanding of the potential traffic volume and National Airspace System (NAS) capacity for small on-demand aircraft operations. Future demand projections use the Transportation Systems Analysis Model (TSAM), a tool suite developed by NASA and the Transportation Laboratory of Virginia Polytechnic Institute. Demand projections from TSAM contain the mode of travel, number of trips and geographic distribution of trips. For this study, the mode of travel can be commercial aircraft, automobile and on-demand aircraft. NASA's Airspace Concept Evaluation System (ACES) is used to assess NAS impact. This simulation takes a schedule that includes all flights: commercial passenger and cargo; conventional General Aviation and on-demand small aircraft, and operates them in the simulated NAS. The results of this analysis projects very large trip numbers for an on-demand air transportation system competitive with automobiles in cost per passenger mile. The significance is this type of air transportation can enhance mobility for communities that currently lack access to commercial air transportation. Another significant finding is that the large numbers of operations can have an impact on the current NAS infrastructure used by commercial airlines and cargo operators, even if on-demand traffic does not use the 28 airports in the Continental U.S. designated as large hubs by the FAA. Some smaller airports will experience greater demand than their current capacity allows and will require upgrading. In addition, in future years as demand grows and vehicle performance improves other non-conventional facilities such as short runways incorporated into

  17. Spatial regression analysis of traffic crashes in Seoul.

    Science.gov (United States)

    Rhee, Kyoung-Ah; Kim, Joon-Ki; Lee, Young-Ihn; Ulfarsson, Gudmundur F

    2016-06-01

    Traffic crashes can be spatially correlated events and the analysis of the distribution of traffic crash frequency requires evaluation of parameters that reflect spatial properties and correlation. Typically this spatial aspect of crash data is not used in everyday practice by planning agencies and this contributes to a gap between research and practice. A database of traffic crashes in Seoul, Korea, in 2010 was developed at the traffic analysis zone (TAZ) level with a number of GIS developed spatial variables. Practical spatial models using available software were estimated. The spatial error model was determined to be better than the spatial lag model and an ordinary least squares baseline regression. A geographically weighted regression model provided useful insights about localization of effects. The results found that an increased length of roads with speed limit below 30km/h and a higher ratio of residents below age of 15 were correlated with lower traffic crash frequency, while a higher ratio of residents who moved to the TAZ, more vehicle-kilometers traveled, and a greater number of access points with speed limit difference between side roads and mainline above 30km/h all increased the number of traffic crashes. This suggests, for example, that better control or design for merging lower speed roads with higher speed roads is important. A key result is that the length of bus-only center lanes had the largest effect on increasing traffic crashes. This is important as bus-only center lanes with bus stop islands have been increasingly used to improve transit times. Hence the potential negative safety impacts of such systems need to be studied further and mitigated through improved design of pedestrian access to center bus stop islands. PMID:26994374

  18. Application of Probability Methods to Assess Crash Modeling Uncertainty

    Science.gov (United States)

    Lyle, Karen H.; Stockwell, Alan E.; Hardy, Robin C.

    2007-01-01

    Full-scale aircraft crash simulations performed with nonlinear, transient dynamic, finite element codes can incorporate structural complexities such as: geometrically accurate models; human occupant models; and advanced material models to include nonlinear stress-strain behaviors, and material failure. Validation of these crash simulations is difficult due to a lack of sufficient information to adequately determine the uncertainty in the experimental data and the appropriateness of modeling assumptions. This paper evaluates probabilistic approaches to quantify the effects of finite element modeling assumptions on the predicted responses. The vertical drop test of a Fokker F28 fuselage section will be the focus of this paper. The results of a probabilistic analysis using finite element simulations will be compared with experimental data.

  19. Risk assessment of accident associated with aircraft transportation

    International Nuclear Information System (INIS)

    The new 1996 IAEA regulation for the transportation of radioactive material states a 90 m/s drop test on unyielding surface for packages transported by air. This figure originates from a statistical analysis on civil aircraft accident during the period 1975 to 1985. A review on the 1983-1989 period demonstrates comparable velocity with a less stringent definition of accident. The statistical analyses are combined with the hardness of the fly-over ground and the impact angle to generate probabilities curves giving the occurrence of a mechanical stress overtaking the drop test velocity. The following steps were carried out: statistical analysis of the accident database from the ICOA (International Civil Aviation Organisation) to appreciate the accident characteristics with special attention to the impact velocity and angle. Modelling of the impact speed in each phase of flight (Take off, Climbing, Cruise, Approach and Landing), in order to evaluate the probability of occurrence of a given crash impact for different flight configurations. Qualitative analysis of recorder failures available in France. As the statistical analysis is based on the available impact speed, a bias can be introduced if major crashes are neglected. In this respect, the qualitative analysis should give some elements to characterize the relationship between the non-availability of the information recorded on the black box and the severity of the accident. (author)

  20. Proceedings of impact of aircraft emissions upon the atmosphere. V. 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The study of the effect of aircraft on atmosphere is a new challenge that the scientific community has to face. This conference`s topics are various aspects of this challenge. The seven sessions of Volume 1 are: Present status and perspectives; Emission and traffic; Physics and chemistry of the aircraft wake; Natural and anthropogenic emissions - specific instrumentation; Global scale - chemistry; Global scale - climate. The 51 papers of Vol. 1. were indexed and abstracted individually for the Energy Database. (R.P.)

  1. Evaluation of the First Transport Rotorcraft Airframe Crash Testbed (TRACT 1) Full-Scale Crash Test

    Science.gov (United States)

    Annett, Martin S.; Littell, Justin D.; Jackson, Karen E.; Bark, Lindley W.; DeWeese, Rick L.; McEntire, B. Joseph

    2014-01-01

    In 2012, the NASA Rotary Wing Crashworthiness Program initiated the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program by obtaining two CH-46E helicopters from the Navy CH-46E Program Office (PMA-226) at the Navy Flight Readiness Center in Cherry Point, North Carolina. Full-scale crash tests were planned to assess dynamic responses of transport-category rotorcraft under combined horizontal and vertical impact loading. The first crash test (TRACT 1) was performed at NASA Langley Research Center's Landing and Impact Research Facility (LandIR), which enables the study of critical interactions between the airframe, seat, and occupant during a controlled crash environment. The CH-46E fuselage is categorized as a medium-lift rotorcraft with fuselage dimensions comparable to a regional jet or business jet. The first TRACT test (TRACT 1) was conducted in August 2013. The primary objectives for TRACT 1 were to: (1) assess improvements to occupant loads and displacement with the use of crashworthy features such as pre-tensioning active restraints and energy absorbing seats, (2) develop novel techniques for photogrammetric data acquisition to measure occupant and airframe kinematics, and (3) provide baseline data for future comparison with a retrofitted airframe configuration. Crash test conditions for TRACT 1 were 33-ft/s forward and 25-ft/s vertical combined velocity onto soft soil, which represent a severe, but potentially survivable impact scenario. The extraordinary value of the TRACT 1 test was reflected by the breadth of meaningful experiments. A total of 8 unique experiments were conducted to evaluate ATD responses, seat and restraint performance, cargo restraint effectiveness, patient litter behavior, and photogrammetric techniques. A combination of Hybrid II, Hybrid III, and ES-2 Anthropomorphic Test Devices (ATDs) were placed in forward and side facing seats and occupant results were compared against injury criteria. Loads from ATDs in energy

  2. Optimized reinforcement of nuclear power plant structures for aircraft impact forces

    International Nuclear Information System (INIS)

    Reactor buildings of nuclear power plants and, to some extent also other buildings of the plant, according to the present safety requirements, have to be able to withstand aircraft impact forces. The building has to withstand this loading only once since afterwards it will be out of use. Accordingly, other criteria for design and the necessary safety measures are valid than in the case of service loads. Large deformations and the development of large cracks due to such loadings are insignificant from a construction point of view for reinforced concrete structures i.e. the stresses can build up to the ultimate load carrying capacity. From the nuclear safety point of view, however, some restrictions are possible in this regard e.g. to obstruct the penetration of fuel through the cracks. Basically all mild steels, with large ducility and without brittle fracture under sudden load increase, are suitable for this purpose. High stresses in the structure would, however, require uneconomical concentrations of mild steel. It is for this reason that the use of high strength steels e.g. St 110/135, has been introduced in Germany for this kind of loading. Through the use of wire strands or cables of high strength steel it is possible to reach a condition of cracks and large deformations due to ultimate loads in zone of point loading. The reinforcement takes on a distinctly curved shape and is able to carry the normal loads and shears through a suspension-structure action. The deformability of the structure for the analysed limit load state can be further increased through a bond-free net. This measure allows a more uniform sketching of the cables or strands over a larger zone. (Auth.)

  3. A crash programme scenario for the Canadian oil sands industry

    International Nuclear Information System (INIS)

    The report Peaking of World Oil Production: Impacts, Mitigation and Risk Management, by Robert L. Hirsch et al., concludes that Peak Oil is going to happen and that worldwide large-scale mitigation efforts are necessary to avoid its possible devastating effects for the world economy. These efforts include accelerated production, referred to as crash programme production, from Canada's oil sands. The objective of this article is to investigate and analyse what production levels that might be reasonable to expect from a crash programme for the Canadian oil sands industry, within the time frame 2006-2018 and 2006-2050. The implementation of a crash programme for the Canadian oil sands industry is associated with serious difficulties. There is not a large enough supply of natural gas to support a future Canadian oil sands industry with today's dependence on natural gas. It is possible to use bitumen as fuel and for upgrading, although it seems to be incompatible with Canada's obligations under the Kyoto treaty. For practical long-term high production, Canada must construct nuclear facilities to generate energy for the in situ projects. Even in a very optimistic scenario Canada's oil sands will not prevent Peak Oil. A short-term crash programme from the Canadian oil sands industry achieves about 3.6 mb/d by 2018. A long-term crash programme results in a production of approximately 5 mb/d by 2030

  4. Building concepts against airplane crash

    International Nuclear Information System (INIS)

    In Germany safety related buildings of nuclear facilities as well as their equipment are to be designed against airplane crash. While the safety of the structure itself can always be guaranteed by structural means, the induced vibrations may cause severe problems for the equipment. Considerable effort was expended in recent years to comprehend the load case airplane crash in a more exact manner and to evaluate reasonable floor response spectra. Besides this analytical effort, investigations are cited to minimize the induced vibrations by new structural concepts. The present paper gives a survey concerning the development of structural concepts, culminating in the double shell structures that are state of the art today. Then the idea of spring supports, as it is known for the aseismic foundation of buildings, is further developed to a new spring concept which reduces the induced vibrations in an optimum way in the load case airplane crash and which additionally isolates earthquake vibrations. (orig.)

  5. Toward Reduced Aircraft Community Noise Impact Via a Perception-Influenced Design Approach

    Science.gov (United States)

    Rizzi, Stephen A.

    2016-01-01

    This is an exciting time for aircraft design. New configurations, including small multi-rotor uncrewed aerial systems, fixed- and tilt-wing distributed electric propulsion aircraft, high-speed rotorcraft, hybrid-electric commercial transports, and low-boom supersonic transports, are being made possible through a host of propulsion and airframe technology developments. The resulting noise signatures may be radically different, both spectrally and temporally, than those of the current fleet. Noise certification metrics currently used in aircraft design do not necessarily reflect these characteristics and therefore may not correlate well with human response. Further, as operations and missions become less airport-centric, e.g., those associated with on-demand mobility or package delivery, vehicles may operate in closer proximity to the population than ever before. Fortunately, a new set of tools are available for assessing human perception during the design process in order to affect the final design in a positive manner. The tool chain utilizes system noise prediction methods coupled with auralization and psychoacoustic testing, making possible the inclusion of human response to noise, along with performance criteria and certification requirements, into the aircraft design process. Several case studies are considered to illustrate how this approach could be used to influence the design of future aircraft.

  6. Passive PWR plants. Results of the effect of an Aircraft impact on the EPP. the DTN approach

    International Nuclear Information System (INIS)

    Aircraft impact on a nuclear power plant produces local effects regarding the structural integrity of the buildings, as well as a vibrational state which may affect the correct operation of the necessary equipment for plant safety. The evaluation of these effects must include both the local structural analysis and the obtainment of loads in equipment location points within the plant, so as to compare them with their capability to withstand dynamic stresses. The capacity of equipment items can be determined on the basis of dynamic tests performed on them, particularly in the plant seismic qualification process. A load caused by aircraft impact requires detailed analysis of the impact wave transmission through the structures of the plant. The local study may be carried out based on simplified formulae contained in the documentation, or on more detailed analysis of non-linear materials. This paper describes tasks undertaken and results obtained by DTN during the study of this impact on AP-600. These tasks are included in the activities performed in the EPP LAY-OUT WORKING GROUP. (Author)

  7. Triple Oxygen Isotope Measurement of Nitrate to Analyze Impact of Aircraft Emissions

    Science.gov (United States)

    Chan, Sharleen

    With 4.9% of total anthropogenic radiative forcing attributed to aircraft emissions, jet engines combust copious amounts of fuel producing gases including: NOx (NO + NO2), SOx, VOC's and fine particles [IPCC (1999), IPCC (2007), Lee et al., 2009]. The tropospheric non-linear relationships between NOx, OH and O3 contribute uncertainties in the ozone budget amplified by poor understanding of the NOx cycle. In a polluted urban environment, interaction of gases and particles produce various new compounds that are difficult to measure with analytical tools available today [Thiemens, 2006]. Using oxygen triple isotopic measurement of NO3 to investigate gas to particle formation and chemical transformation in the ambient atmosphere, this study presents data obtained from aerosols sampled at NASA's Dryden Aircraft Operations Facility (DAOF) in Palmdale, CA during January and February, 2009 and Los Angeles International Airport (LAX) during Fall 2009, Winter 2010, and Spring 2010. The aerosols collected from jet aircraft exhaust in Palmdale exhibit an oxygen isotope anomaly (Delta17O =delta 17O -0.52 delta18O) increase with photochemical age of particles (-0.22 to 26.41‰) while NO3 concentration decreases from 53.76 - 5.35ppm with a radial distance from the jet dependency. Bulk aerosol samples from LAX exhibit seasonal variation with Delta17 O and NO3 concentration peaking in winter suggesting multiple sources and increased fossil fuel burning. Using oxygen triple isotopes of NO3, we are able to distinguish primary and secondary nitrate by aircraft emissions allowing new insight into a portion of the global nitrogen cycle. This represents a new and potentially important means to uniquely identify aircraft emissions on the basis of the unique isotopic composition of jet aircraft emissions.

  8. Impact of Cabin Ozone Concentrations on Passenger Reported Symptoms in Commercial Aircraft

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Allen, Joseph G.; Weschler, Charles J.;

    2015-01-01

    Due to elevated ozone concentrations at high altitudes, the adverse effect of ozone on air quality, human perception and health may be more pronounced in aircraft cabins. The association between ozone and passenger-reported symptoms has not been investigated under real conditions since smoking was...... banned on aircraft and ozone converters became more common. Indoor environmental parameters were measured at cruising altitude on 83 US domestic and international flights. Passengers completed a questionnaire about symptoms and satisfaction with the indoor air quality. Average ozone concentrations were...

  9. Study of the impact of cruise speed on scheduling and productivity of commercial transport aircraft

    Science.gov (United States)

    Bond, E. Q.; Carroll, E. A.; Flume, R. A.

    1977-01-01

    A comparison is made between airplane productivity and utilization levels derived from commercial airline type schedules which were developed for two subsonic and four supersonic cruise speed aircraft. The cruise speed component is the only difference between the schedules which are based on 1995 passenger demand forecasts. Productivity-to-speed relationships were determined for the three discrete route systems: North Atlantic, Trans-Pacific, and North-South America. Selected combinations of these route systems were also studied. Other areas affecting the productivity-to-speed relationship such as aircraft design range and scheduled turn time were examined.

  10. Distracted Driving Raises Crash Risk

    Science.gov (United States)

    ... a Seriously Ill Child Featured Website: NIDA for Teens Past Issues Most Viewed February 2014 Print RSS Find us on Facebook External link, please review our exit disclaimer . Subscribe Distracted Driving Raises Crash Risk Video technology and in-vehicle sensors showed that distracted driving, ...

  11. Market Crashes without External Shocks

    OpenAIRE

    Sergiu Hart; Yair Tauman

    2004-01-01

    It is shown here that market crashes and bubbles can arise without external shocks. Sudden changes in behavior coming after a long period of stationarity may be the result of endogenous information processing. Except for the daily observation of the market, there is no new information, no communication and no coordination among the participants.

  12. Knowledge crash and knowledge management

    OpenAIRE

    Ermine, Jean-Louis

    2010-01-01

    This article, by including the problem of “Knowledge Crash” in the more general framework of “Knowledge Management”, enlarges the concepts of knowledge, generation and knowledge transfer. It proposes a global approach, starting from a strategic analysis of a knowledge capital and ending in the implementation of socio-technical devices for inter-generational knowledge transfer.

  13. Crash Frequency Modeling Using Real-Time Environmental and Traffic Data and Unbalanced Panel Data Models.

    Science.gov (United States)

    Chen, Feng; Chen, Suren; Ma, Xiaoxiang

    2016-01-01

    Traffic and environmental conditions (e.g., weather conditions), which frequently change with time, have a significant impact on crash occurrence. Traditional crash frequency models with large temporal scales and aggregated variables are not sufficient to capture the time-varying nature of driving environmental factors, causing significant loss of critical information on crash frequency modeling. This paper aims at developing crash frequency models with refined temporal scales for complex driving environments, with such an effort providing more detailed and accurate crash risk information which can allow for more effective and proactive traffic management and law enforcement intervention. Zero-inflated, negative binomial (ZINB) models with site-specific random effects are developed with unbalanced panel data to analyze hourly crash frequency on highway segments. The real-time driving environment information, including traffic, weather and road surface condition data, sourced primarily from the Road Weather Information System, is incorporated into the models along with site-specific road characteristics. The estimation results of unbalanced panel data ZINB models suggest there are a number of factors influencing crash frequency, including time-varying factors (e.g., visibility and hourly traffic volume) and site-varying factors (e.g., speed limit). The study confirms the unique significance of the real-time weather, road surface condition and traffic data to crash frequency modeling. PMID:27322306

  14. IDENTIFICATION OF AIRCRAFT HAZARDS

    International Nuclear Information System (INIS)

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7)

  15. IDENTIFICATION OF AIRCRAFT HAZARDS

    Energy Technology Data Exchange (ETDEWEB)

    K.L. Ashley

    2005-03-23

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7).

  16. Identification of Aircraft Hazards

    Energy Technology Data Exchange (ETDEWEB)

    K. Ashley

    2006-12-08

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7).

  17. Identification of Aircraft Hazards

    International Nuclear Information System (INIS)

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7)

  18. Icing – A Risk Factor in Aviation.Case Study: the Plane Crash in the Apuseni Mountains (Romania on 20.01.2014.

    Directory of Open Access Journals (Sweden)

    Şchiopu Cosmin-Liviu

    2015-05-01

    Full Text Available Icing - a risk factor in aviation. Case study: The plane crash in the Apuseni Mountains (Romania on 20.01.2014. Icing is a potentially harmful weather phenomenon for flight safety. Icing, irrespective of its forms, has a negative impact on all aviation activities since it severely impedes the aerodynamic properties of an aircraft, sometimes to such an extent that flying and landing may become impossible. Icing is a serious weather threat to aviation and may ultimately lead to deadly events. One such unfortunate event took place in the Western (Apuseni Mountains on the 20.01.2014, when an aircraft which was transporting a medical team on a humanitarian mission, simply crashed down in the area of the Western (Apuseni Mountains, at around 4:00 pm local time. The present study actually makes an inventory of the extremely hazardous flying conditions, by thoroughly analyzing the weather reports and data, as well as visual and synoptic messages or official elements and information from that very day. All these materials show that the flight route and the airdrome of destination were under the influence of a front which accounted for very poor meteorological conditions. On such bad weather, the flight was practically doomed to failure since low snow and sleet-bearing clouds were hanging down over the mountaintops. Flying straight through these clouds made any landmarks impossible to be seen and, furthermore, lack of orientation created false perceptions which led to fatal misjudgements and errors.

  19. Suicide plane crash against nuclear power plants

    International Nuclear Information System (INIS)

    Cea (French atomic energy commission) and EDF (Electricity of France) are reassessing their safety standards concerning suicide plane attacks against nuclear facilities. The general idea is to study the non-linear behaviour of reinforced concrete in case of mechanical impact. American studies carried out in 1988 show that a F-14 phantom crashing into a 3,6 meter thick wall at a speed of 774 km/h penetrates only the first 5 cm of the wall. More recent studies performed in Germany and based on computerized simulations show that the reactor containment can sustain impacts from a F15 plane or even from a 747-Boeing but contiguous buildings like the one which houses spent fuels might be more easily damaged because of their metal roofing. (A.C.)

  20. Modeling crash spatial heterogeneity: random parameter versus geographically weighting.

    Science.gov (United States)

    Xu, Pengpeng; Huang, Helai

    2015-02-01

    The widely adopted techniques for regional crash modeling include the negative binomial model (NB) and Bayesian negative binomial model with conditional autoregressive prior (CAR). The outputs from both models consist of a set of fixed global parameter estimates. However, the impacts of predicting variables on crash counts might not be stationary over space. This study intended to quantitatively investigate this spatial heterogeneity in regional safety modeling using two advanced approaches, i.e., random parameter negative binomial model (RPNB) and semi-parametric geographically weighted Poisson regression model (S-GWPR). Based on a 3-year data set from the county of Hillsborough, Florida, results revealed that (1) both RPNB and S-GWPR successfully capture the spatially varying relationship, but the two methods yield notably different sets of results; (2) the S-GWPR performs best with the highest value of Rd(2) as well as the lowest mean absolute deviance and Akaike information criterion measures. Whereas the RPNB is comparable to the CAR, in some cases, it provides less accurate predictions; (3) a moderately significant spatial correlation is found in the residuals of RPNB and NB, implying the inadequacy in accounting for the spatial correlation existed across adjacent zones. As crash data are typically collected with reference to location dimension, it is desirable to firstly make use of the geographical component to explore explicitly spatial aspects of the crash data (i.e., the spatial heterogeneity, or the spatially structured varying relationships), then is the unobserved heterogeneity by non-spatial or fuzzy techniques. The S-GWPR is proven to be more appropriate for regional crash modeling as the method outperforms the global models in capturing the spatial heterogeneity occurring in the relationship that is model, and compared with the non-spatial model, it is capable of accounting for the spatial correlation in crash data. PMID:25460087

  1. Transport jet aircraft noise abatement in foreign countries: Growth, structure, impact. Volume 1: Europe, July 1980

    Science.gov (United States)

    Spencer, F. A.

    1980-01-01

    The development and implementation of aircraft noise control regulations in various European states are described. The countries include the United Kingdom, France, Switzerland, Federal Republic of Germany, Sweden, Denmark, and the Netherlands. Topics discussed include noise monitoring, airport curfews, land use planning, and the government structure for noise regulation.

  2. Braking News: the Link between Crash Severity and Crash Avoidance Maneuvers

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    2012-01-01

    This study focuses on the linkage between crash severity and crash avoidance maneuvers. Various emergency lateral and speed control maneuvers are considered in response to different critical events that made the crash imminent. Partial proportional odds models are estimated to accommodate the...... ordered-response nature of severity while allowing for changes in effects across severity levels. The data sample for estimation consists of single-vehicle crashes extracted from the General Estimates System (GES) crash database for the period 2005-2009. Results show the correlation between crash...... avoidance maneuvers and crash severity, with differences emerging for different critical events. Moreover, results show two trends: (i) most drivers fail to act when facing critical events, and (ii) drivers rarely perform crash avoidance maneuvers that are correlated with higher probability of lower crash...

  3. Prioritizing Highway Safety Manual's crash prediction variables using boosted regression trees.

    Science.gov (United States)

    Saha, Dibakar; Alluri, Priyanka; Gan, Albert

    2015-06-01

    The Highway Safety Manual (HSM) recommends using the empirical Bayes (EB) method with locally derived calibration factors to predict an agency's safety performance. However, the data needs for deriving these local calibration factors are significant, requiring very detailed roadway characteristics information. Many of the data variables identified in the HSM are currently unavailable in the states' databases. Moreover, the process of collecting and maintaining all the HSM data variables is cost-prohibitive. Prioritization of the variables based on their impact on crash predictions would, therefore, help to identify influential variables for which data could be collected and maintained for continued updates. This study aims to determine the impact of each independent variable identified in the HSM on crash predictions. A relatively recent data mining approach called boosted regression trees (BRT) is used to investigate the association between the variables and crash predictions. The BRT method can effectively handle different types of predictor variables, identify very complex and non-linear association among variables, and compute variable importance. Five years of crash data from 2008 to 2012 on two urban and suburban facility types, two-lane undivided arterials and four-lane divided arterials, were analyzed for estimating the influence of variables on crash predictions. Variables were found to exhibit non-linear and sometimes complex relationship to predicted crash counts. In addition, only a few variables were found to explain most of the variation in the crash data. PMID:25823903

  4. Impacts of aircraft emissions on the air quality near the ground

    OpenAIRE

    Lee, H; S. C. Olsen; Wuebbles, D. J.; D. Youn

    2013-01-01

    The continuing increase in demand for commercial aviation transport raises questions about the effects of resulting emissions on the environment. The purpose of this study is to investigate, using a global chemistry transport model, to what extent aviation emissions outside the boundary layer influence air quality in the boundary layer. The effects of current levels of aircraft emissions were studied through comparison of multiple simulations allowing for the separated effects of aviation emi...

  5. Impacts of aircraft emissions on the air quality near the ground

    OpenAIRE

    Lee, H; S. C. Olsen; Wuebbles, D. J.; D. Youn

    2013-01-01

    The continuing increase in demand for commercial aviation transport raises questions about the effects of resulting emissions on the environment. The purpose of this study is to investigate, using a global chemistry transport model, to what extent aviation emissions outside the boundary layer influence air quality in the boundary layer. The large-scale effects of current levels of aircraft emissions were studied through comparison of multiple simulations allowing for the separated effects of ...

  6. Impacts of aircraft emissions on the air quality near the ground

    OpenAIRE

    Lee, H; S. C. Olsen; Wuebbles, D. J.; D. Youn

    2013-01-01

    The continuing increase in demand for commercial aviation transport raises questions about the effects of resulting emissions on the environment. The purpose of this study is to investigate, using a global chemistry transport model, to what extent aviation emissions outside the boundary layer influence air quality in the boundary layer. The large-scale effects of current levels of aircraft emissions were studied through comparison of multiple simulations allowing for the sep...

  7. Impact of future fuel properties on aircraft engines and fuel systems

    Science.gov (United States)

    Rudey, R. A.; Grobman, J. S.

    1978-01-01

    From current projections of the availability of high-quality petroleum crude oils, it is becoming increasingly apparent that the specifications for hydrocarbon jet fuels may have to be modified. The problems that are most likely to be encountered as a result of these modifications relate to engine performance, component durability and maintenance, and aircraft fuel-system performance. The effect on engine performance will be associated with changes in specific fuel consumption, ignition at relight limits, at exhaust emissions. Durability and maintenance will be affected by increases in combustor liner temperatures, carbon deposition, gum formation in fuel nozzles, and erosion and corrosion of turbine blades and vanes. Aircraft fuel-system performance will be affected by increased deposits in fuel-system heat exchangers and changes in the pumpability and flowability of the fuel. The severity of the potential problems is described in terms of the fuel characteristics most likely to change in the future. Recent data that evaluate the ability of current-technology aircraft to accept fuel specification changes are presented, and selected technological advances that can reduce the severity of the problems are described and discussed.

  8. A strategy for climate evaluation of aircraft technology: an efficient climate impact assessment tool – AirClim

    Directory of Open Access Journals (Sweden)

    A. Stenke

    2007-08-01

    Full Text Available Climate change is a challenge to society and to cope with requires assessment tools which are suitable to evaluate new technology options with respect to their impact on climate. Here we present AirClim, a model which comprises a linearisation of the processes occurring from the emission to an estimate in near surface temperature change, which is presumed to be a reasonable indicator for climate change. The model is designed to be applicable to aircraft technology, i.e.~the climate agents CO2, H2O, CH4 and O3 (latter two resulting from NOx-emissions and contrails are taken into account. It employs a number of precalculated atmospheric data and combines them with aircraft emission data to obtain the temporal evolution of atmospheric concentration changes, radiative forcing and temperature changes. The linearisation is based on precalculated data derived from 25 steady-state simulations of the state-of-the-art climate-chemistry model E39/C, which include sustained normalised emissions at various atmospheric regions. The results show that strongest climate impacts from ozone changes occur for emissions in the tropical upper troposphere (60 mW/m²; 80 mK for 1 TgN emitted, whereas from methane in the middle tropical troposphere (–2.7% change in methane lifetime; –30 mK per TgN. The estimate of the temperature changes caused by the individual climate agents takes into account a perturbation lifetime, related to the region of emission. A comparison of this approach with results from the TRADEOFF and SCENIC projects shows reasonable agreement with respect to concentration changes, radiative forcing, and temperature changes. The total impact of a supersonic fleet on radiative forcing (mainly water vapour is reproduced within 5%. For subsonic air traffic (sustained emissions after 2050 results show that although ozone-radiative forcing is much less important than that from CO2 for the year 2100. However the impact on temperature is of comparable size

  9. Design of the RC containment shell of a nuclear reactor for aircraft impact

    International Nuclear Information System (INIS)

    This paper deals with the following points: i) Characterization of a particular region of the shell which is modeled as a one-degree-of freedom system for the non-linear dynamic analysis. This is achieved through a proper interpretation of the results of the global analysis. ii) Development of a method of non-linear dynamic analysis for the considered one-degree-of freedom model. iii) Comparative analysis of the design for flexural strength, and punching shear, according to American and German standards. Interaction diagrams for bending and normal force are developed according to the two standards. The concepts of the foregoing items are exemplified with the verification of the shell reinforcement of a PWR reactor. A simplified method of non-linear dynamic analysis for airplane crash is presented. This method takes into account all the important influences of the problem. The results of this analysis are used in the design of the shell reinforcement according to American and German Standards. (orig./HP)

  10. Prescription medicines and the risk of road traffic crashes: a French registry-based study.

    Directory of Open Access Journals (Sweden)

    Ludivine Orriols

    Full Text Available BACKGROUND: In recent decades, increased attention has been focused on the impact of disabilities and medicinal drug use on road safety. The aim of our study was to investigate the association between prescription medicines and the risk of road traffic crashes, and estimate the attributable fraction. METHODS AND FINDINGS: We extracted and matched data from three French nationwide databases: the national health care insurance database, police reports, and the national police database of injurious crashes. Drivers identified by their national health care number involved in an injurious crash in France, between July 2005 and May 2008, were included in the study. Medicines were grouped according to the four risk levels of the French classification system (from 0 [no risk] to 3 [high risk]. We included 72,685 drivers involved in injurious crashes. Users of level 2 (odds ratio [OR]  = 1.31 [1.24-1.40] and level 3 (OR  = 1.25 [1.12-1.40] prescription medicines were at higher risk of being responsible for a crash. The association remained after adjustment for the presence of a long-term chronic disease. The fraction of road traffic crashes attributable to levels 2 and 3 medications was 3.3% [2.7%-3.9%]. A within-person case-crossover analysis showed that drivers were more likely to be exposed to level 3 medications on the crash day than on a control day, 30 days earlier (OR  = 1.15 [1.05-1.27]. CONCLUSION: The use of prescription medicines is associated with a substantial number of road traffic crashes in France. In light of the results, warning messages appear to be relevant for level 2 and 3 medications and questionable for level 1 medications. A follow-up study is needed to evaluate the impact of the warning labeling system on road traffic crash prevention.

  11. Cost of Physical Vehicle Crash Testing

    OpenAIRE

    Baguley, Paul; Roy, Rajkumar; James W. Watson

    2008-01-01

    The automotive safety-testing environment currently deploys virtual methods and physical crash testing for new product development and validation in safety testing legislation. Cost benefit analysis of crash testing is considered here by estimating the cost of physical crash testing. This has been achieved via the compilation of detailed process maps and AS-IS analyses of the current physical testing procedures. This leads on to detailed work and cost breakdown structures used in the comparat...

  12. Abdominal Injury Patterns in Real Frontal Crashes: Influence of Crash Conditions, Occupant Seat and Restraint Systems

    OpenAIRE

    Lamielle, S.; CUNY,S; Foret-Bruno, JY.; Petit, P.; VEZIN,P; Verriest, JP.; Guillemot, H.

    2006-01-01

    An in-depth study was conducted through the analysis of medical reports and crash data from real world accidents. The objective was to investigate the abdominal injury patterns among car occupants in frontal crashes. The influence of the type of restraint system, the occupant seat, the age and the crash severity was investigated. The results indicate that the risk of abdominal AIS 3+ injuries increased with crash severity and decreased with the introduction of belt retractors. Rear belted pas...

  13. Predicting Crashes Using Traffic Offences. A Meta-Analysis that Examines Potential Bias between Self-Report and Archival Data

    Science.gov (United States)

    af Wåhlberg, Anders; Freeman, James; Watson, Barry; Watson, Angela

    2016-01-01

    Background Traffic offences have been considered an important predictor of crash involvement, and have often been used as a proxy safety variable for crashes. However the association between crashes and offences has never been meta-analysed and the population effect size never established. Research is yet to determine the extent to which this relationship may be spuriously inflated through systematic measurement error, with obvious implications for researchers endeavouring to accurately identify salient factors predictive of crashes. Methodology and Principal Findings Studies yielding a correlation between crashes and traffic offences were collated and a meta-analysis of 144 effects drawn from 99 road safety studies conducted. Potential impact of factors such as age, time period, crash and offence rates, crash severity and data type, sourced from either self-report surveys or archival records, were considered and discussed. After weighting for sample size, an average correlation of r = .18 was observed over the mean time period of 3.2 years. Evidence emerged suggesting the strength of this correlation is decreasing over time. Stronger correlations between crashes and offences were generally found in studies involving younger drivers. Consistent with common method variance effects, a within country analysis found stronger effect sizes in self-reported data even controlling for crash mean. Significance The effectiveness of traffic offences as a proxy for crashes may be limited. Inclusion of elements such as independently validated crash and offence histories or accurate measures of exposure to the road would facilitate a better understanding of the factors that influence crash involvement. PMID:27128093

  14. AP calculus AB & BC crash course

    CERN Document Server

    Rosebush, J

    2012-01-01

    AP Calculus AB & BC Crash Course - Gets You a Higher Advanced Placement Score in Less Time Crash Course is perfect for the time-crunched student, the last-minute studier, or anyone who wants a refresher on the subject. AP Calculus AB & BC Crash Course gives you: Targeted, Focused Review - Study Only What You Need to Know Crash Course is based on an in-depth analysis of the AP Calculus AB & BC course description outline and actual AP test questions. It covers only the information tested on the exams, so you can make the most of your valuable study time. Written by experienced math teachers, our

  15. AP English language & composition crash course

    CERN Document Server

    Hogue, Dawn

    2012-01-01

    AP English Language & Composition Crash Course - Gets You a Higher Advanced Placement Score in Less Time Crash Course is perfect for the time-crunched student, the last-minute studier, or anyone who wants a refresher on the subject. AP English Language & Composition Crash Course gives you: Targeted, Focused Review - Study Only What You Need to Know Crash Course is based on an in-depth analysis of the AP English Language & Composition course description outline and actual Advanced Placement test questions. It covers only the information tested on the exam, so you can make the most of your valua

  16. Utilizing the eigenvectors of freeway loop data spatiotemporal schematic for real time crash prediction.

    Science.gov (United States)

    Fang, Shou'en; Xie, Wenjing; Wang, Junhua; Ragland, David R

    2016-09-01

    The concept of crash precursor identification is gaining more practicality due to the recent advancements in Advanced Transportation Management and Information Systems. Investigating the shortcomings of the existing models, this paper proposes a new method to model the real time crash likelihood based on loop data through schematic eigenvectors. Firstly, traffic volume, occupancy and density spatiotemporal schematics in certain duration before an accident occurrence were constructed to describe the traffic flow status. Secondly, eigenvectors and eigenvalues of the spatiotemporal schematics were extracted to represent traffic volume, occupancy and density situation before the crash occurrence. Thirdly, by setting the vectors in crash time as case and those at crash free time as control, a logistic model is constructed to identify the crash precursors. Results show that both the eigenvectors and eigenvalues can significantly impact the accident likelihood compared to the previous study, the proposed model has the advantage of avoiding multicollinearity, better reflection of the overall traffic flow status before the crash, and improving missing data problem of loop detectors. PMID:27258946

  17. Risk factors for severe injury in cyclists involved in traffic crashes in Victoria, Australia.

    Science.gov (United States)

    Boufous, Soufiane; de Rome, Liz; Senserrick, Teresa; Ivers, Rebecca

    2012-11-01

    This study examines the impact of cyclist, road and crash characteristics on the injury severity of cyclists involved in traffic crashes reported to the police in Victoria, Australia between 2004 and 2008. Logistic regression analysis was carried out to identify predictors of severe injury (serious injury and fatality) in cyclist crashes reported to the police. There were 6432 cyclist crashes reported to the police in Victoria between 2004 and 2008 with 2181 (33.9%) resulting in severe injury of the cyclist involved. The multivariate analysis found that factors that increase the risk of severe injury in cyclists involved in traffic crashes were age (50 years and older), not wearing a helmet, riding in the dark on unlit roads, riding on roads zoned 70 km/h or above, on curved sections of the road, in rural locations and being involved in head-on collisions as well as off path crashes, which include losing control of vehicle, and on path crashes which include striking the door of a parked vehicle. While this study did not test effectiveness of preventative measures, policy makers should consider implementation of programs that address these risk factors including helmet programs and environmental modifications such as speed reduction on roads that are frequented by cyclists. PMID:23036419

  18. High-speed rail with emerging automobiles and aircraft can reduce environmental impacts in California’s future

    Science.gov (United States)

    Chester, Mikhail; Horvath, Arpad

    2012-09-01

    Sustainable mobility policy for long-distance transportation services should consider emerging automobiles and aircraft as well as infrastructure and supply chain life-cycle effects in the assessment of new high-speed rail systems. Using the California corridor, future automobiles, high-speed rail and aircraft long-distance travel are evaluated, considering emerging fuel-efficient vehicles, new train designs and the possibility that the region will meet renewable electricity goals. An attributional per passenger-kilometer-traveled life-cycle inventory is first developed including vehicle, infrastructure and energy production components. A consequential life-cycle impact assessment is then established to evaluate existing infrastructure expansion against the construction of a new high-speed rail system. The results show that when using the life-cycle assessment framework, greenhouse gas footprints increase significantly and human health and environmental damage potentials may be dominated by indirect and supply chain components. The environmental payback is most sensitive to the number of automobile trips shifted to high-speed rail, and for greenhouse gases is likely to occur in 20-30 years. A high-speed rail system that is deployed with state-of-the-art trains, electricity that has met renewable goals, and in a configuration that endorses high ridership will provide significant environmental benefits over existing modes. Opportunities exist for reducing the long-distance transportation footprint by incentivizing large automobile trip shifts, meeting clean electricity goals and reducing material production effects.

  19. High-speed rail with emerging automobiles and aircraft can reduce environmental impacts in California’s future

    International Nuclear Information System (INIS)

    Sustainable mobility policy for long-distance transportation services should consider emerging automobiles and aircraft as well as infrastructure and supply chain life-cycle effects in the assessment of new high-speed rail systems. Using the California corridor, future automobiles, high-speed rail and aircraft long-distance travel are evaluated, considering emerging fuel-efficient vehicles, new train designs and the possibility that the region will meet renewable electricity goals. An attributional per passenger-kilometer-traveled life-cycle inventory is first developed including vehicle, infrastructure and energy production components. A consequential life-cycle impact assessment is then established to evaluate existing infrastructure expansion against the construction of a new high-speed rail system. The results show that when using the life-cycle assessment framework, greenhouse gas footprints increase significantly and human health and environmental damage potentials may be dominated by indirect and supply chain components. The environmental payback is most sensitive to the number of automobile trips shifted to high-speed rail, and for greenhouse gases is likely to occur in 20–30 years. A high-speed rail system that is deployed with state-of-the-art trains, electricity that has met renewable goals, and in a configuration that endorses high ridership will provide significant environmental benefits over existing modes. Opportunities exist for reducing the long-distance transportation footprint by incentivizing large automobile trip shifts, meeting clean electricity goals and reducing material production effects. (letter)

  20. Impact of cabin ozone concentrations on passenger reported symptoms in commercial aircraft.

    Directory of Open Access Journals (Sweden)

    Gabriel Bekö

    Full Text Available Due to elevated ozone concentrations at high altitudes, the adverse effect of ozone on air quality, human perception and health may be more pronounced in aircraft cabins. The association between ozone and passenger-reported symptoms has not been investigated under real conditions since smoking was banned on aircraft and ozone converters became more common. Indoor environmental parameters were measured at cruising altitude on 83 US domestic and international flights. Passengers completed a questionnaire about symptoms and satisfaction with the indoor air quality. Average ozone concentrations were relatively low (median: 9.5 ppb. On thirteen flights (16% ozone levels exceeded 60 ppb, while the highest peak level reached 256 ppb for a single flight. The most commonly reported symptoms were dry mouth or lips (26%, dry eyes (22.1% and nasal stuffiness (18.9%. 46% of passengers reported at least one symptom related to the eyes or mouth. A third of the passengers reported at least one upper respiratory symptom. Using multivariate logistic (individual symptoms and linear (aggregated continuous symptom variables regression, ozone was consistently associated with symptoms related to the eyes and certain upper respiratory endpoints. A concentration-response relationship was observed for nasal stuffiness and eye and upper respiratory symptom indicators. Average ozone levels, as opposed to peak concentrations, exhibited slightly weaker associations. Medium and long duration flights were significantly associated with more symptoms compared to short flights. The relationship between ultrafine particles and ozone on flights without meal service was indicative of ozone-initiated chemistry.

  1. 轿车-电动自行车侧面碰撞事故再现分析%Reconstruction analysis of car-electric bicycle side impact accident based on PC-Crash

    Institute of Scientific and Technical Information of China (English)

    徐梦雪; 林庆峰; 王伟

    2013-01-01

    In order to reconstruct car to electric bicycle side impact accidents, the simulation tests of car to electric bicycle side impact collisions were conducted by using PC-Crash. The various impact locations between the cyclist's head and the hood of vehicle were analyzed at different impact speeds, the relationship between the vehicle impact speeds and the cyclist's head injuries was discussed, the relationship between the vehicle impact speeds and the cyclist's throw distances was analyzed, and the cyclist throw distance models was established and compared with foreign similar model. The results show that collision vehicle speed of 50 km/h can be thought as the cyclist's head injury collision vehicle speed threshold. When the collision vehicle speed is less than 40 km/h, the throw distance tendency is the same to the stillness of the electric bicycle and vehicle movement, when the collision vehicle speed is higher than 40 km/h, compared with impact motion of the electric bicycle, vehicle and static electric bicycle collision can make rider throwing distance slightly larger, but the electric bicycle throw distance distribution is discrete. It is effective to reconstruct the vehicle impact speeds by the cyclist's impact locations, head injuries and throw distances in car to electric bicycle side impact accidents. 6 figs, 13 refs.%为了再现轿车与电动自行车的侧面碰撞事故,利用PC-Crash进行了轿车与电动自行车的侧面碰撞模拟试验,分析了不同车辆碰撞速度下骑车人头部与车辆引擎罩及风挡玻璃撞击的位置,探讨了车辆碰撞速度与骑车人头部损伤的关系,建立了骑车人抛距模型,并与国外模型进行了对比.研究结果表明:碰撞车速为50 km/h可以认为是骑车人头部伤害的碰撞速度阈值;当碰撞车速低于40 km/h时,车辆撞击运动和静止的电动自行车,骑车人抛距变化的趋势基本相似;当碰撞车速高于40 km/h时,与撞击运动的电动自行车

  2. Can a stochastic cusp catastrophe model explain stock market crashes?

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Vošvrda, Miloslav

    2009-01-01

    Roč. 33, č. 10 (2009), s. 1824-1836. ISSN 0165-1889 R&D Projects: GA ČR GD402/09/H045; GA ČR GA402/09/0965 Grant ostatní: GAUK(CZ) 46108 Institutional research plan: CEZ:AV0Z10750506 Keywords : Stochastic cusp catastrophe * Bifurcations * Singularity * Nonlinear dynamics * Stock market crash Subject RIV: AH - Economics Impact factor: 1.097, year: 2009

  3. Predictive estimates for behaviour in the train crash demonstration

    International Nuclear Information System (INIS)

    Predictive work for the Train Crash Demonstration included estimates of the post-impact behaviour of the flask, flatrol, locomotive and carriages. These estimates were produced using hand calculations and desk study of certain relevant railway incidents. Because of the natural uncertainties in the process, an event 'tree' was constructed to show the various possible motions foreseen. Observations from the Demonstration are summarised and compared with the estimates. (author)

  4. Database improvements for motor vehicle/bicycle crash analysis

    OpenAIRE

    Lusk, Anne C; Asgarzadeh, Morteza; Farvid, Maryam S

    2015-01-01

    Background: Bicycling is healthy but needs to be safer for more to bike. Police crash templates are designed for reporting crashes between motor vehicles, but not between vehicles/bicycles. If written/drawn bicycle-crash-scene details exist, these are not entered into spreadsheets. Objective: To assess which bicycle-crash-scene data might be added to spreadsheets for analysis. Methods: Police crash templates from 50 states were analysed. Reports for 3350 motor vehicle/bicycle crashes (2011) w...

  5. Finite element analysis of occupant head injuries: parametric effects of the side curtain airbag deployment interaction with a dummy head in a side impact crash.

    Science.gov (United States)

    Deng, Xingqiao; Potula, S; Grewal, H; Solanki, K N; Tschopp, M A; Horstemeyer, M F

    2013-06-01

    In this study, we investigated and assessed the dependence of dummy head injury mitigation on the side curtain airbag and occupant distance under a side impact of a Dodge Neon. Full-scale finite element vehicle simulations of a Dodge Neon with a side curtain airbag were performed to simulate the side impact. Owing to the wide range of parameters, an optimal matrix of finite element calculations was generated using the design method of experiments (DOE); the DOE method was performed to independently screen the finite element results and yield the desired parametric influences as outputs. Also, analysis of variance (ANOVA) techniques were used to analyze the finite element results data. The results clearly show that the influence of moving deformable barrier (MDB) strike velocity was the strongest influence parameter on both cases for the head injury criteria (HIC36) and the peak head acceleration, followed by the initial airbag inlet temperature. Interestingly, the initial airbag inlet temperature was only a ~30% smaller influence than the MDB velocity; also, the trigger time was a ~54% smaller influence than the MDB velocity when considering the peak head accelerations. Considering the wide range in MDB velocities used in this study, results of the study present an opportunity for design optimization using the different parameters to help mitigate occupant injury. As such, the initial airbag inlet temperature, the trigger time, and the airbag pressure should be incorporated into vehicular design process when optimizing for the head injury criteria. PMID:23567214

  6. Hot-Air Balloon Tours: Crash Epidemiology in the United States, 2000-2011

    Science.gov (United States)

    Ballard, Sarah-Blythe; Beaty, Leland P.; Baker, Susan P.

    2016-01-01

    Introduction Hot-air balloon tours are FAR Part 91-governed balloon rides conducted for compensation or hire. Part 91, General Aviation, in general involves the least strict federal regulations and accounts for the majority of aviation crashes and fatalities. Methods National Transportation Safety Board reports of hot-air balloon tour crashes in the United States from 2000 through 2011 were read and analyzed. Results During the 12-yr period, 78 hot-air balloon tours crashed, involving 518 occupants. There were 91 serious injuries and 5 fatalities; 83% of crashes resulted in one or more serious or fatal outcomes. Of the serious injuries characterized, 56% were lower extremity fractures. Most crashes (81%) occurred during landing; 65% involved hard landings. Fixed object collisions contributed to 50% of serious injuries and all 5 fatalities. During landing sequences, gondola dragging, tipping, bouncing, and occupant ejection were associated with poor outcomes. Of the crashes resulting in serious or fatal outcomes, 20% of balloons were significantly damaged or destroyed. Discussion The incidence of morbidity and mortality is high among hot-air balloon tour crashes, and the proportion of balloon crashes attributed to paid rides appears to have increased over time. In addition to examining the role of restraint systems, personal protective equipment, and power line emergency procedures in ballooning, injury prevention efforts should target factors such hard landings, object strikes, gondola instability, and occupant ejections, which are associated with balloon injuries and deaths. Crash outcomes may also improve with vehicle engineering that enables balloons themselves to absorb impact forces. PMID:24279231

  7. Detection of the Impact of Ice Crystal Accretion in an Aircraft Engine Compression System During Dynamic Operation

    Science.gov (United States)

    May, Ryan D.; Simon, Donald L.; Guo, Ten-Huei

    2014-01-01

    The accretion of ice in the compression system of commercial gas turbine engines operating in high ice water content conditions is a safety issue being studied by the aviation community. While most of the research focuses on the underlying physics of ice accretion and the meteorological conditions in which accretion can occur, a systems-level perspective on the topic lends itself to potential near-term operational improvements. Here a detection algorithm is developed which has the capability to detect the impact of ice accretion in the Low Pressure Compressor of an aircraft engine during steady flight as well as during changes in altitude. Unfortunately, the algorithm as implemented was not able to distinguish throttle changes from ice accretion and thus more work remains to be done.

  8. Property Damage Crash Equivalency Factors for Solving the Crash Frequency-Severity Dilemma: Case Study on South Korean Rural Roads

    OpenAIRE

    Oh, Jutaek; Washington, Simon; Lee, Dongmin

    2010-01-01

    Safety interventions (e.g. median barriers, photo enforcement) and road features (e.g. median type and width) can influence crash severities, crash frequencies, or both. Both dimensions—crash frequency and crash severity—are needed to obtain a full accounting of road safety. Extensive literature and common sense both dictate that all crashes are not ‘created’ equal—with fatalities costing society more than 1000 times the cost of property damage only crashes. Despite this glowing disparity, th...

  9. Cervical spine response in frontal crash.

    Science.gov (United States)

    Panzer, Matthew B; Fice, Jason B; Cronin, Duane S

    2011-11-01

    Predicting neck response and injury resulting from motor vehicle accidents is essential to improving occupant protection. A detailed human cervical spine finite element model has been developed, with material properties and geometry determined a priori of any validation, for the evaluation of global kinematics and tissue-level response. Model validation was based on flexion/extension response at the segment level, tension response of the whole ligamentous cervical spine, head kinematic response from volunteer frontal impacts, and soft tissue response from cadaveric whole cervical spine frontal impacts. The validation responses were rated as 0.79, assessed using advanced cross-correlation analysis, indicating the model exhibits good biofidelity. The model was then used to evaluate soft tissue response in frontal impact scenarios ranging from 8G to 22G in severity. Disc strains were highest in the C4-C5-C6 segments, and ligament strains were greatest in the ISL and LF ligaments. Both ligament and disc fiber strain levels exceeded the failure tolerances in the 22G case, in agreement with existing data. This study demonstrated that a cervical spine model can be developed at the tissue level and provide accurate biofidelic kinematic and local tissue response, leading to injury prediction in automotive crash scenarios. PMID:21665513

  10. Seat Design for Crash Worthiness

    Science.gov (United States)

    Pinkel, I Irving; Rosenberg, Edmund G

    1957-01-01

    A study of many crash deceleration records suggested a simplified model of a crash deceleration pulse, which incorporates the essential properties of the pulse. The model pulse is considered to be composed of a base pulse on which are superimposed one or more secondary pulses of shorter duration. The results of a mathematical analysis of the seat-passenger deceleration in response to the airplane deceleration pulse are provided. On the basis of this information, presented as working charts, the maximum deceleration loads experienced by the seat and passenger in response to the airplane deceleration pulse can be computed. This maximum seat-passenger deceleration is found to depend on the natural frequency of the seat containing the passenger, considered as a mass-spring system. A method is presented that shows how to arrive at a combination of seat strength, natural frequency, and ability to absorb energy in deformation beyond the elastic limit that will allow the seat to serve without failure during an airplane deceleration pulse taken as the design requirement.

  11. Evaluation on the structural soundness of the transport package for low-level radioactive waste for subsurface disposal against aircraft impact by finite element method

    International Nuclear Information System (INIS)

    The structural analysis of aircraft crush on the transport package for low-level radioactive waste was performed using the impact force which was already used for the evaluation of the high-level waste transport package by LSDYNA code. The transport package was deformed, and stresses due to the crush exceeded elastic range. However, plastic strains yieled in the package were far than the elongation of the materials and the body of the package did not contact the disposal packages due to the deformation of the package. Therefore, it was confirmed that the package keeps its integrity against aircraft crush. (author)

  12. Response of equipment in nuclear power plants to airplane crash

    International Nuclear Information System (INIS)

    Nuclear power plants in Germany are to be designed against airplane crash. Two problems arise: first, the local problem of penetration as well as local destruction of the building and secondly the airplane induced vibrations of the whole building which cause loadings for secondary systems (equipment). This paper deals especially with the second problem. Floor response spectra due to airplane crash are presented for two different power plant buildings. The influence of various parameters (time history of excitation, direction and location of impact, mathematical model, soil, damping, etc.) are discussed. A comparison with the results of earthquake loading is given. Suggestions are made for developing suitable floor design spectra and using them to analyse multidegree-of-freedom systems. However, the paper gives only a partial answer to the questions arising because of some important restrictions which had to be made. Studies concerning these restrictions are still being conducted and will be presented in a separate paper. (Auth.)

  13. FOG RISKS IN AVIATION. CASE STUDY: PLANE CRASH AT SMOLENSK (RUSSIA ON 10.04.2010

    Directory of Open Access Journals (Sweden)

    ŞCHIOPU COSMIN-LIVIU

    2013-03-01

    Full Text Available Fog, irrespective of its forms, has a negative impact on all aviation activities. Fog severely diminishes visibility, sometimes to such an extent that landing may become impossible. Fog is a serious weather threat and hazard in aviation and may produce deadly events. One such unfortunate event took place at Smolensk (Russia, on 10.04.2010, when the presidential aircraft, which was transporting Poland’s President, together with an official delegation, to commemorate 70 years from the Katyn massacre, simply crashed down close to the Smolensk North military aerodrome, at local hour 10:41:07.The present study actually makes an inventory of the extremely hazardous flying conditions, by thoroughly analyzing the weather reports and data, as well as visual and synoptic messages or official elements and information from that very day. All these materials show that the airdrome of destination was under the influence of a very active anti-cyclonic ridge, which accounted for very poor meteorological conditions. On such severe weather, the flight was doomed since greatly reduced visibility due to dense fog made landmarks orientation almost impossible and, furthermore, created false perceptions which led to fatal misjudgements and errors.

  14. Adjusting for car occupant injury liability in relation to age, speed limit, and gender-specific driver crash involvement risk.

    Science.gov (United States)

    Keall, Michael; Frith, William

    2004-12-01

    It is well established that older drivers' fragility is an important factor associated with higher levels of fatal crash involvement for older drivers. There has been less research on age-related fragility with respect to the sort of minor injuries that are more common in injury crashes. This study estimates a quantity that is related to injury fragility: the probability that a driver or a passenger of that driver will be injured in crashes involving two cars. The effects of other factors apart from drivers' fragility are included in this measure, including the fragility of the passengers, the crashworthiness of cars driven, seatbelt use by the occupants, and characteristics of crashes (including configuration and impact speed). The car occupant injury liability estimates appropriately includes these factors to adjust risk curves by age, gender, and speed limit accounting for overrepresentation in crashes associated with fragility and these other factors. PMID:15545071

  15. Aircraft measurements of the impacts of pollution aerosols on clouds and precipitation over the Sierra Nevada

    Science.gov (United States)

    Rosenfeld, Daniel; Woodley, William L.; Axisa, Duncan; Freud, Eyal; Hudson, James G.; Givati, Amir

    2008-08-01

    Recent publications suggest that anthropogenic aerosols suppress orographic precipitation in California and elsewhere. A field campaign (SUPRECIP: Suppression of Precipitation) was conducted to investigate this hypothesized aerosol effect. The campaign consisted of in situ aircraft measurements of the polluting aerosols, the composition of the clouds ingesting them, and the way the precipitation-forming processes are affected. SUPRECIP was conducted during February and March of 2005 and February and March of 2006. The flights documented the aerosols and orographic clouds flowing into the central Sierra Nevada from the upwind densely populated industrialized/urbanized areas and contrasted them with the aerosols and clouds downwind of the sparsely populated areas in the northern Sierra Nevada. SUPRECIP found that the aerosols transported from the coastal regions are augmented greatly by local sources in the Central Valley resulting in high concentrations of aerosols in the eastern parts of the Central Valley and the Sierra foothills. This pattern is consistent with the detected patterns of suppressed orographic precipitation, occurring primarily in the southern and central Sierra Nevada, but not in the north. The precipitation suppression occurs mainly in the orographic clouds that are triggered from the boundary layer over the foothills and propagate over the mountains. The elevated orographic clouds that form at the crest are minimally affected. The clouds are affected mainly during the second half of the day and the subsequent evening, when solar heating mixes the boundary layer up to cloud bases. Local, yet unidentified nonurban sources are suspected to play a major role.

  16. The impact from emitted NO{sub x} and VOC in an aircraft plume. Model results for the free troposphere

    Energy Technology Data Exchange (ETDEWEB)

    Pleijel, K.

    1998-04-01

    The chemical fate of gaseous species in a specific aircraft plume is investigated using an expanding box model. The model treats the gas phase chemical reactions in detail, while other parameters are subject to a high degree of simplification. Model simulations were carried out in a plume up to an age of three days. The role of emitted VOC, NO{sub x} and CO as well as of background concentrations of VOC, NO{sub x} and ozone on aircraft plume chemistry was investigated. Background concentrations were varied in a span of measured values in the free troposphere. High background concentrations of VOC were found to double the average plume production of ozone and organic nitrates. In a high NO{sub x} environment the plume production of ozone and organic nitrates decreased by around 50%. The production of nitric acid was found to be less sensitive to background concentrations of VOC, and increased by up to 50% in a high NO{sub x} environment. Mainly, emitted NO{sub x} caused the plume production of ozone, nitric acid and organic nitrates. The ozone production during the first hours is determined by the relative amount of NO{sub 2} in the NO{sub x} emissions. The impact from emitted VOC was in relative values up to 20% of the ozone production and 65% of the production of organic nitrates. The strongest relative influence from VOC was found in an environment characterized by low VOC and high NO{sub x} background concentrations, where the absolute peak production was lower than in the other scenarios. The effect from emitting VOC and NO{sub x} at the same time added around 5% for ozone, 15% for nitric acid and 10% for organic nitrates to the plume production caused by NO{sub x} and VOC when emitted separately 47 refs, 15 figs, 4 tabs

  17. A Finite Element Model of the THOR-K Dummy for Aerospace and Aircraft Impact Simulations

    Science.gov (United States)

    Putnam, Jacob; Untaroiu, Costin D.; Somers, Jeffrey T.; Pellettiere, Joseph

    2013-01-01

    1) Update and Improve the THOR Finite Element (FE) model to specifications of the latest mod kit (THOR-K). 2) Evaluate the kinematic and kinetic response of the FE model in frontal, spinal, and lateral impact loading conditions.

  18. Impact of the european emission trading scheme for the air transportation industry on the valuation of aircraft purchase rights

    International Nuclear Information System (INIS)

    The European Commission issued a legislative proposal in December 2006, suggesting a cap on CO2 emissions for all planes arriving or departing from EU airports, while allowing airlines to buy and sell pollution credits on the EU carbon market (Emission Trading Scheme, or ETS). In 2008 the new scheme got the final approval. Real options appear to be ab appropriate methodology to capture the extra value brought by the new legislation on new airplane purchase rights: The airline will surely have the purchase right to the new plane if the operation of the plane generates unused pollution credits that the airline can sell at a minimum price in the carbon market. This paper tries to determine if the impact of ETS in the valuation of aircraft purchase rights is significant enough in monetary terms to include the new legislation in a complex real-option model already proposed by the authors recently. The research concludes that even the impact of ETS justifies its inclusion in the model, the quality of the available sets of historical data still raises some questions. Particularly, the assumption of market efficiency for the Carbon Pool over the recent years needs to be treated with caution. (Author) 9 refs

  19. Impact of the chosen turbulent flow empirical model on the prediction of sound radiation and vibration by aircraft panels

    Science.gov (United States)

    Rocha, Joana

    2016-07-01

    A precise definition of the turbulent boundary layer excitation is required to accurately predict the sound radiation and surface vibration levels, produced by an aircraft panel excited turbulent flow during flight. Hence, any existing inaccuracy on turbulent boundary layer excitation models leads to an inaccurate prediction of the panel response. A number of empirical models have been developed over the years to provide the turbulent boundary layer wall pressure spectral density. However, different empirical models provide dissimilar predictions for the wall pressure spectral density. The objective of the present study is to investigate and quantify the impact of the chosen empirical model on the predicted radiated sound power, and on the predicted panel surface acceleration levels. This study provides a novel approach and a detailed analysis on the use of different turbulent boundary layer wall pressure empirical models, and impact on mathematical predictions. Closed-form mathematical relationships are developed, and recommendations are provided for the level of deviation and uncertainty associated to different models, in relation to a baseline model, both for panel surface acceleration and radiated sound power.

  20. Impacts of aircraft emissions on the air quality near the ground

    Directory of Open Access Journals (Sweden)

    H. Lee

    2013-06-01

    Full Text Available The continuing increase in demand for commercial aviation transport raises questions about the effects of resulting emissions on the environment. The purpose of this study is to investigate, using a global chemistry transport model, to what extent aviation emissions outside the boundary layer influence air quality in the boundary layer. The large-scale effects of current levels of aircraft emissions were studied through comparison of multiple simulations allowing for the separated effects of aviation emissions occurring in the low, middle and upper troposphere. We show that emissions near cruise altitudes (9–11 km in altitude rather than emissions during landing and take-off are responsible for most of the total odd-nitrogen (NOy, ozone (O3 and aerosol perturbations near the ground with a noticeable seasonal difference. Overall, the perturbations of these species are smaller than 1 ppb even in winter when the perturbations are greater than in summer. Based on the widely used air quality standards and uncertainty of state-of-the-art models, we conclude that aviation-induced perturbations have a negligible effect on air quality even in areas with heavy air traffic. Aviation emissions lead to a less than 1% aerosol enhancement in the boundary layer due to a slight increase in ammonium nitrate (NH4NO3 during cold seasons and a statistically insignificant aerosol perturbation in summer. In addition, statistical analysis using probability density functions, Hellinger distance, and p value indicate that aviation emissions outside the boundary layer do not affect the occurrence of extremely high aerosol concentrations in the boundary layer. An additional sensitivity simulation assuming the doubling of surface ammonia emissions demonstrates that the aviation induced aerosol increase near the ground is highly dependent on background ammonia concentrations whose current range of uncertainty is large.

  1. Impacts of aircraft emissions on the air quality near the ground

    Directory of Open Access Journals (Sweden)

    H. Lee

    2013-01-01

    Full Text Available The continuing increase in demand for commercial aviation transport raises questions about the effects of resulting emissions on the environment. The purpose of this study is to investigate, using a global chemistry transport model, to what extent aviation emissions outside the boundary layer influence air quality in the boundary layer. The effects of current levels of aircraft emissions were studied through comparison of multiple simulations allowing for the separated effects of aviation emissions occurring in the low, middle and upper troposphere. We show that emissions near cruise altitudes rather than emissions during landing and take-off are responsible for most of the total odd-nitrogen (NOy, ozone (O3 and aerosol perturbations near the ground with a noticeable seasonal difference. Overall, the perturbations of these species are smaller than 1 ppb even in winter when the perturbations are greater than in summer. Based on the widely used air quality standards and uncertainty of state-of-the-art models, we conclude that aviation-induced perturbations have a negligible effect on air quality even in areas with heavy air traffic. Aviation emissions lead to a less than 1% aerosol enhancement in the boundary layer due to a slight increase in ammonium nitrate (NH4NO3 during cold seasons and a statistically insignificant aerosol perturbation in summer. In addition, statistical analysis using probability density functions, Hellinger distance, and p-value indicate that aviation emissions outside the boundary layer do not affect the occurrence of extremely high aerosol concentrations in the boundary layer. An additional sensitivity simulation assuming the doubling of surface ammonia emissions demonstrates that the aviation induced aerosol increase near the ground is highly dependent on background ammonia concentrations whose current range of uncertainty is large.

  2. Modelling Strategies for Predicting the Residual Strength of Impacted Composite Aircraft Fuselages

    Science.gov (United States)

    Lachaud, Frederic; Espinosa, Christine; Michel, Laurent; Rahme, Pierre; Piquet, Robert

    2015-12-01

    Aeronautic Certification rules established for the metallic materials are not convenient for the composite structures concerning the resistance against impact. The computer-based design is a new methodology that is thought about to replace the experimental tests. It becomes necessary for numerical methods to be robust and predictive for impact. Three questions are addressed in this study: (i) can a numerical model be "mechanically intrinsic" to predict damage after impact, (ii) can this model be the same for a lab sample and a large structure, and (iii) can the numerical model be predictive enough to predict the Compression After Impact (CAI)? Three different computational strategies are used and compared: a Cohesive Model (CM), a Continuous Damage Model (CDM) coupling failure modes and damage, and a Mixed Methodology (MM) using the CDM for delamination initiation and the CM for cracks propagation. The first attempts to use the Smooth Particle Hydrodynamics method are presented. Finally, impact on a fuselage is modelled and a numerical two-stage strategy is developed to predict the CAI.

  3. 49 CFR 238.403 - Crash energy management.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Crash energy management. 238.403 Section 238.403... Equipment § 238.403 Crash energy management. (a) Each power car and trailer car shall be designed with a crash energy management system to dissipate kinetic energy during a collision. The crash...

  4. Factors Contributing to Crashes among Young Drivers

    Directory of Open Access Journals (Sweden)

    Lyndel J. Bates

    2014-08-01

    Full Text Available Young drivers are the group of drivers most likely to crash. There are a number of factors that contribute to the high crash risk experienced by these drivers. While some of these factors are intrinsic to the young driver, such as their age, gender or driving skill, others relate to social factors and when and how often they drive. This article reviews the factors that affect the risk of young drivers crashing to enable a fuller understanding of why this risk is so high in order to assist in developing effective countermeasures.

  5. Car crash and injury among young drivers: contribution of social, circumstantial and car attributes.

    Science.gov (United States)

    Laflamme, L; Vaez, M

    2007-03-01

    The objective of the study was to assess the independent contribution of individual, car and circumstantial features in severe and fatal car crashes involving young drivers. A prospective longitudinal, register-based cohort study was conducted at national level (in Sweden), in which people born in the years 1970-1972 (n = 334070) were followed up for the period 1988-2000 (aged 16-18 years in 1988) for their first two-car crashes leading to severe or fatal injury. Ten variables descriptive of the driver (sociodemographics), the car (safety level) and the crash have been analysed using multiple logistic regressions for male and female drivers separately, compiling crude and adjusted odds ratios with 95% CI. When controlling for other features, none of the variables descriptive of male and female drivers' socio-demographic characteristics impacts significantly on the odds of being severely injured or dying in a car-to-car crash. After adjustment, significant excess risks are observed for speed limits higher than the lowest one, type of crash other than rear end collision and road and light conditions other than favourable (dry and daylight), for both male and female drivers. For males only, cars from all car safety levels have significantly higher odds than those from the safest category. Among male and female young drivers, class differences in the risk of being severely injured in a traffic injury are substantial. Yet, despite this imbalance, crash characteristics (for males and females) and safety level of the vehicle driven (for males) remain the most determinant factors of crash severity. Understanding the social patterning of road traffic injuries is a challenge for public health and it seems that qualitative and quantitative differences in crash exposure offer part of the explanation. Young drivers from all social groups need, however, to be sensitized to the risk factors. PMID:17624005

  6. Impact Testing and Analysis of Composites for Aircraft Engine Fan Cases

    Science.gov (United States)

    Roberts, Gary D.; Revilock, Duane M.; Binienda, Wieslaw K.; Nie, Walter Z.; Mackenzie, S. Ben; Todd, Kevin B.

    2002-01-01

    The fan case in a jet engine is a heavy structure because of its size and because of the requirement that it contain a blade released during engine operation. Composite materials offer the potential for reducing the weight of the case. Efficient design, test, and analysis methods are needed to efficiently evaluate the large number of potential composite materials and design concepts. The type of damage expected in a composite case under blade-out conditions was evaluated using a subscale test in which a glass/epoxy composite half-ring target was impacted with a wedge-shaped titanium projectile. Fiber shearing occurred near points of contact between the projectile and target. Delamination and tearing occurred on a larger scale. These damage modes were reproduced in a simpler test in which flat glass/epoxy composites were impacted with a blunt cylindrical projectile. A surface layer of ceramic eliminated fiber shear fracture but did not reduce delamination. Tests on 3D woven carbon/epoxy composites indicated that transverse reinforcement is effective in reducing delamination. A 91 cm (36 in.) diameter full-ring sub-component was proposed for larger scale testing of these and other composite concepts. Explicit, transient, finite element analyses indicated that a full-ring test is needed to simulate complete impact dynamics, but simpler tests using smaller ring sections are adequate when evaluation of initial impact damage is the primary concern.

  7. Study on the design basis accident 'aircraft impact on nuclear power plant'

    International Nuclear Information System (INIS)

    This report contains the analysis of an accidental impact of a Phantom F-4F Jet against the secondary containment of a present PWR-plant. The different submodels which have been used for the simulation of the effects of such an external event are described and the results are presented. (orig.)

  8. The impact of self healing materials on telecommunication: towards a concrete aircraft?

    OpenAIRE

    Schmets, A. J. M.

    2006-01-01

    The use of a material for a specific application is governed by considerations on the expected conditions during its lifetime. For aerospace applications for instance, lightness, reliability and thermal stability ofthe material are of major importance. No material will ever possess all the desired properties at the same time. Therefore the engineer is left with optimising the materials and minimise the impact of the ever-present 'disadvantageous' properties. By introducing the potential of 'S...

  9. Bird impact at aircraft structure - Damage analysis using Coupled Euler Lagrangian Approach

    Science.gov (United States)

    Smojver, I.; Ivancevic, D.

    2010-06-01

    Numerical bird strike damage prediction procedure has been applied on the very detailed large airplane secondary structure consisting of sandwich, composite and metallic structural items. The impacted inboard flap finite element model is modelled using 3D, shell and continuum shell elements, coupled with appropriate kinematic constraints. The bird has been modelled using Coupled Euler Lagrangian approach, in order to avoid the numerical difficulties connected with mesh distortion. Various failure modes, such as Carbon Fibre Reinforced Plastics (CFRP) face layer rupture, failure of composite matrix, damage initiation / evolution in the sandwich structure Nomex core and elastoplastic failure of a metallic structure have been investigated. Besides, general contact has been applied as to efficiently capture the contact between Eulerian bird material and the structure, as well as large deformations of the different structural components. Compared to the classic Lagrangian modelling of the bird, the analysis has proven to be more stable, and the results, such as damage areas, physically more realistic. The impact has been applied in the area that is the most probably subjected to the impact damage during exploitation.

  10. Bird impact at aircraft structure - Damage analysis using Coupled Euler Lagrangian Approach

    International Nuclear Information System (INIS)

    Numerical bird strike damage prediction procedure has been applied on the very detailed large airplane secondary structure consisting of sandwich, composite and metallic structural items. The impacted inboard flap finite element model is modelled using 3D, shell and continuum shell elements, coupled with appropriate kinematic constraints. The bird has been modelled using Coupled Euler Lagrangian approach, in order to avoid the numerical difficulties connected with mesh distortion. Various failure modes, such as Carbon Fibre Reinforced Plastics (CFRP) face layer rupture, failure of composite matrix, damage initiation / evolution in the sandwich structure Nomex core and elastoplastic failure of a metallic structure have been investigated. Besides, general contact has been applied as to efficiently capture the contact between Eulerian bird material and the structure, as well as large deformations of the different structural components. Compared to the classic Lagrangian modelling of the bird, the analysis has proven to be more stable, and the results, such as damage areas, physically more realistic. The impact has been applied in the area that is the most probably subjected to the impact damage during exploitation.

  11. Mixed logit model-based driver injury severity investigations in single- and multi-vehicle crashes on rural two-lane highways.

    Science.gov (United States)

    Wu, Qiong; Chen, Feng; Zhang, Guohui; Liu, Xiaoyue Cathy; Wang, Hua; Bogus, Susan M

    2014-11-01

    Crashes occurring on rural two-lane highways are more likely to result in severe driver incapacitating injuries and fatalities. In this study, mixed logit models are developed to analyze driver injury severities in single-vehicle (SV) and multi-vehicle (MV) crashes on rural two-lane highways in New Mexico from 2010 to 2011. A series of significant contributing factors in terms of driver behavior, weather conditions, environmental characteristics, roadway geometric features and traffic compositions, are identified and their impacts on injury severities are quantified for these two types of crashes, respectively. Elasticity analyses and transferability tests were conducted to better understand the models' specification and generality. The research findings indicate that there are significant differences in causal attributes determining driver injury severities between SV and MV crashes. For example, more severe driver injuries and fatalities can be observed in MV crashes when motorcycles or trucks are involved. Dark lighting conditions and dusty weather conditions are found to significantly increase MV crash injury severities. However, SV crashes demonstrate different characteristics influencing driver injury severities. For example, the probability of having severe injury outcomes is higher when vans are identified in SV crashes. Drivers' overtaking actions will significantly increase SV crash injury severities. Although some common attributes, such as alcohol impaired driving, are significant in both SV and MV crash severity models, their effects on different injury outcomes vary substantially. This study provides a better understanding of similarities and differences in significant contributing factors and their impacts on driver injury severities between SV and MV crashes on rural two-lane highways. It is also helpful to develop cost-effective solutions or appropriate injury prevention strategies for rural SV and MV crashes. PMID:25016459

  12. Energy absorption capability of foam-based composite materials and their applications as seat cushions in aircraft crashworthiness

    Science.gov (United States)

    Kh. Beheshti, Hamid

    This study is focusing on the application of foam materials in aviation. These materials are being used for acoustic purposes, as padding in the finished interior panels of the aircraft, and as seat cushions. Foams are mostly used in seating applications. Since seat cushion is directly interacting with the body of occupant, it has to be ergonomically comfortable beside of absorbing the energy during the impact. All the seats and seat cushions have to pass regulations defined by Federal Aviation Administration (FAA). In fact, all airplane companies are required to certify the subcomponents of aircrafts before installing them on the main structure, fuselage. Current Federal Aviation Administration Regulations require a dynamic sled test of the entire seat system for certifying the seat cushions. This dynamic testing is required also for replacing the deteriorated cushions with new cushions. This involves a costly and time-consuming certification process. AGATE group has suggested a procedure based on quasi-static testing in order to certify new seat cushions without conducting full-scale dynamic sled testing. AGATE subcomponent methodology involves static tests of the energy-absorbing foam cushions and design validation by conducting a full-scale dynamic seat test. Microscopic and macroscopic studies are necessary to provide a complete understanding about performance of foams during the crash. Much investigation has been done by different sources to obtain the reliable modeling in terms of demonstration of mechanical behavior of foams. However, rate sensitivity of foams needs more attention. A mathematical hybrid dynamic model for the cushion underneath of the human body will be taken into consideration in this research. Analytical and finite element codes such as MADYMO and LS-DYNA codes have the potential to greatly speed up the crashworthy design process, to help certify seats and aircraft to dynamic crash loads, to predict seat and occupant response to impact

  13. Amplification and Asymmetry in Crashes and Frenzies

    OpenAIRE

    Han N. Ozsoylev

    2005-01-01

    We often observe disproportionate reactions to tangible information in large stock price movements. Moreover these movements feature an asymmetry: the number of crashes is more than that of frenzies in the S&P 500 index. This paper offers an explanation for these two characteristics of large movements in which hedging (portfolio insurance) causes amplified price reactions to news and liquidity shocks as well as an asymmetry biased towards crashes. Risk aversion of traders is shown to be essen...

  14. Marijuana Use and Motor Vehicle Crashes

    OpenAIRE

    Li, Mu-Chen; Brady, Joanne E.; DiMaggio, Charles J.; Lusardi, Arielle R.; Tzong, Keane Y.; Li, Guohua

    2011-01-01

    Since 1996, 16 states and the District of Columbia in the United States have enacted legislation to decriminalize marijuana for medical use. Although marijuana is the most commonly detected nonalcohol drug in drivers, its role in crash causation remains unsettled. To assess the association between marijuana use and crash risk, the authors performed a meta-analysis of 9 epidemiologic studies published in English in the past 2 decades identified through a systematic search of bibliographic data...

  15. Crash Recovery for Embedded Main Memory Database

    OpenAIRE

    Fang Ye; Shuang Wang; Yi-bing Li

    2012-01-01

    In the last years, the deployment of embedded real-time communication systems has increased dramatically. At the same time, the amount of data that needs to be managed by embedded real-time main memory databases is increasing, thus requiring an efficient data management. However, system crash will cause data loss in main memory, which will seriously affect the normal operation of the entire communication system. This paper introduces an algorithm of system crash recovery applied in main memor...

  16. Posttraumatic Growth After Motor Vehicle Crashes.

    Science.gov (United States)

    Wu, Kitty K; Leung, Patrick W L; Cho, Valda W; Law, Lawrence S C

    2016-06-01

    The relationship between sub-dimensions of posttraumatic growth (PTG) and distress was investigated for survivors of motor vehicle crashes (MVC). PTG and symptoms of posttraumatic stress disorder (PTSD) for 1045 MVC survivors who attended the Accident and Emergency Services were examined with the Chinese versions of the Posttraumatic Growth Inventory (PTGI) and the Impact of Event Scale-Revised 1 week after the experience of a MVC. A factor structure, which was different from both the original English version of the PTGI and the Chinese version of PTGI for cancer survivors, was identified. Factors extracted were: (1) Life and Self Appreciation; (2) New Commitments; (3) Enlightenment; and (4) Relating to Others. However, correlation analyses indicated a functional similarity between factors from this study and those from previous studies. Relations between PTG sub-dimensions and PTSD symptoms were identified. Results from hierarchical multiple regression analysis and structural equation modeling show that there were different predictors for different PTG sub-dimensions. Findings suggest that different modes of relationship between PTSD symptoms and PTG sub-dimensions may co-exist. PMID:27040687

  17. Effect of drop size on the impact thermodynamics for supercooled large droplet in aircraft icing

    Science.gov (United States)

    Zhang, Chen; Liu, Hong

    2016-06-01

    Supercooled large droplet (SLD), which can cause abnormal icing, is a well-known issue in aerospace engineering. Although efforts have been exerted to understand large droplet impact dynamics and the supercooled feature in the film/substrate interface, respectively, the thermodynamic effect during the SLD impact process has not received sufficient attention. This work conducts experimental studies to determine the effects of drop size on the thermodynamics for supercooled large droplet impingement. Through phenomenological reproduction, the rapid-freezing characteristics are observed in diameters of 400, 800, and 1300 μm. The experimental analysis provides information on the maximum spreading rate and the shrinkage rate of the drop, the supercooled diffusive rate, and the freezing time. A physical explanation of this unsteady heat transfer process is proposed theoretically, which indicates that the drop size is a critical factor influencing the supercooled heat exchange and effective heat transfer duration between the film/substrate interface. On the basis of the present experimental data and theoretical analysis, an impinging heating model is developed and applied to typical SLD cases. The model behaves as anticipated, which underlines the wide applicability to SLD icing problems in related fields.

  18. Automatic detection of aircraft emergency landing sites

    Science.gov (United States)

    Shen, Yu-Fei; Rahman, Zia-ur; Krusienski, Dean; Li, Jiang

    2011-06-01

    An automatic landing site detection algorithm is proposed for aircraft emergency landing. Emergency landing is an unplanned event in response to emergency situations. If, as is unfortunately usually the case, there is no airstrip or airfield that can be reached by the un-powered aircraft, a crash landing or ditching has to be carried out. Identifying a safe landing site is critical to the survival of passengers and crew. Conventionally, the pilot chooses the landing site visually by looking at the terrain through the cockpit. The success of this vital decision greatly depends on the external environmental factors that can impair human vision, and on the pilot's flight experience that can vary significantly among pilots. Therefore, we propose a robust, reliable and efficient algorithm that is expected to alleviate the negative impact of these factors. We present only the detection mechanism of the proposed algorithm and assume that the image enhancement for increased visibility, and image stitching for a larger field-of-view have already been performed on the images acquired by aircraftmounted cameras. Specifically, we describe an elastic bound detection method which is designed to position the horizon. The terrain image is divided into non-overlapping blocks which are then clustered according to a "roughness" measure. Adjacent smooth blocks are merged to form potential landing sites whose dimensions are measured with principal component analysis and geometric transformations. If the dimensions of the candidate region exceed the minimum requirement for safe landing, the potential landing site is considered a safe candidate and highlighted on the human machine interface. At the end, the pilot makes the final decision by confirming one of the candidates, also considering other factors such as wind speed and wind direction, etc. Preliminary results show the feasibility of the proposed algorithm.

  19. IMPACT OF AIRCRAFT TRAFFIC EMISSIONS ON OZONE FORMATION AT THE RIO DE JANEIRO URBAN AREA

    Directory of Open Access Journals (Sweden)

    Guimarães, C.S., Arbilla, G., Corrêa, S.M., Gatti, L.V.

    2007-01-01

    Full Text Available Data for speciated volatile organic compounds (VOC evaluated in Santos-Dumont Airport and Antonio Carlos Jobim International Airport in Rio de Janeiro, Brazil, are reported. VOC were evaluated by gas chromatography with flame ionization detection (GC – FID and mass spectrometry (GC – MS, following the U.S. EPA TO – 15 methodology. At Santos-Dumont Airport were quantified 1376 µg m-3 of VOCs 10 m from runway, 408 µg m-3 inside the airport building, and 116 µg m-3 outside the airport area. At the taxiway area of the International Airport a total of 190 µg m-3 of VOC were quantified. Toluene, the most abundant compound near the Santos-Dumont Airport runway, was obtained in a non-significative concentration outside the airport area. This fact suggests that this area is not noticeably impacted by air traffic. A computational model was developed using the OZIPR program and the SAPRC mechanism. Calculated ozone concentrations are higher than values for downtown area of Rio de Janeiro city. Simulated results show that, for the runway in Santos-Dumont Airport, olefins and aromatics contribute in 57% and 15%, respectively, to ozone formation, toluene being the major contributor. Cis-2-butene is the most reactive species regarding OH reaction.

  20. Estimation of nuclear power plant aircraft hazards

    International Nuclear Information System (INIS)

    The standard procedures for estimating aircraft risk to nuclear power plants provide a conservative estimate, which is adequate for most sites, which are not close to airports or heavily traveled air corridors. For those sites which are close to facilities handling large numbers of aircraft movements (airports or corridors), a more precise estimate of aircraft impact frequency can be obtained as a function of aircraft size. In many instances the very large commercial aircraft can be shown to have an acceptably small impact frequency, while the very small general aviation aircraft will not produce sufficiently serious impact to impair the safety-related functions. This paper examines the in between aircraft: primarily twin-engine, used for business, pleasure, and air taxi operations. For this group of aircraft the total impact frequency was found to be approximately once in one million years, the threshold above which further consideration of specific safety-related consequences would be required

  1. Epidemiology, Causes and Prevention of Car Rollover Crashes with Ejection

    OpenAIRE

    El-Hennawy, HM; El-Menyar, A; Al-Thani, H; Tuma, M; Parchani, A; H. Abdulrahman; Peralta, R; Asim, M.; Zarour, A; Latifi, R

    2014-01-01

    Rollover crashes (ROCs) are responsible for almost a third of all highway vehicle occupant fatalities. Although ROCs are common and serious mechanism of injury, ROCs are under-reported. To analyze the causes, mechanism, impact and prevention of ROCs, we reviewed the literature between 1984 and 2013. By utilizing the search engines PubMed, MEDLINE and EMBASE by using key words “ROCs” “Ejection” and “vehicle” the initial search yielded 241 abstracts, of which 58 articles were relevant. Most of ...

  2. Crash-Induced Vibration and Safety Assessment of Breakaway-Type Post Structures Made of High Anticorrosion Steels

    OpenAIRE

    Lee, Sang-Youl

    2016-01-01

    This study deals with car crash effects and passenger safety assessment of post structures with breakaway types using high performance steel materials. To disperse the impact force when a car crashes into a post, the post could be designed with a breakaway feature. In this study, we used a new high anticorrosion steel for the development of advanced breakaways. Based on the improved Cowper-Symonds model, specific physical properties to the high anticorrosion steel were determined. In particul...

  3. Studying the effect of weather conditions on daily crash counts using a discrete time-series model

    OpenAIRE

    Brijs, Tom; Karlis, Dimitris; Wets, Geert

    2008-01-01

    In previous research, significant effects of weather conditions on car crashes have been found. However, most studies use monthly or yearly data and only few studies are available analyzing the impact of weather conditions on daily car crash counts. Furthermore, the studies that are available on a daily level do not explicitly model the data in a time-series context, hereby ignoring the temporal serial correlation that may be present in the data. In this paper, we introduce an integer autoreg...

  4. Large airplane crash on a nuclear plant

    International Nuclear Information System (INIS)

    A simple scaling formula for impact load calculation is presented and the result of a simple calculation model is discussed. Maximum impact loads are calculated for various aircraft: Phantom-4, Learjet, Cessna-210, Boeing-707 and Boeing-747. It can be concluded that roughly 2 meters of wall are sufficient to prevent the perforation even in the case of the Boeing-747. The acceptability of a lower thickness wall can also be discussed. The problem which remains to be solved is the one of the strong shaking of the structures and of components. In order to solve this problem, a specific design solution is suggested: it essentially consists in assuring to most exposed parts of structures an adequate degree of deformability. The decoupling of the cupola from the rest of the building could be obtained by the introduction of elastic joints and of viscous dampers at the base of the cupola

  5. Modeled Trends in Impacts of Landing and Takeoff Aircraft Emissions on Surface Air-Quality in U.S for 2005, 2010 and 2018

    Science.gov (United States)

    Vennam, L. P.

    2014-12-01

    Understanding the present-day impacts of aircraft emissions on surface air quality is essential to plan potential mitigation policies for future growth. Stringent regulation on mobile source-related emissions in the recent past coupled with anticipated rise in the growth in aviation activity can increase the relative impacts of aviation-attributable surface air quality if adequate measures for reducing aviation emissions are not implemented. Though aircraft emissions during in-flight mode (at upper altitudes) contribute a significant (70 - 80%) proportion of the total aviation emissions, landing and takeoff (LTO) related emissions can have immediate impact on surface air quality, as most of the large airports are located in urban areas, specifically those that are designated in nonattainment for O3 and/or PM2.5. In this study, we modeled impacts of aircraft emissions during LTO cycles on surface air quality using the latest version of the CMAQ model for two contemporary years (2005, 2010) and one future year (2018). For this regional scale modeling study, we used highly resolved aircraft emissions from the FAA's Aviation Environmental Design Tool (AEDT), meteorology from NASA's Modern-Era Retrospective Analysis for Research and Applications (MERRA) downscaled with the WRF model, dynamically varying chemical boundary conditions from the CAM-Chem global model (which also used the same AEDT emissions but at the global scale), and spatio-temporally resolved lightning NOx emissions estimated using National Lightning Detection Network (NLDN) flash density data. We evaluated our model results with air quality observations from surface-based networks and in-situ aircraft observation data for the contemporary years. We will present results from model evaluation using this enhanced modeling system, as well as the trajectories in aviation- related air quality (focusing on O3, NO2 and PM2.5) for the three modeling years considered in this study. These findings will help plan

  6. Property Damage Crash Equivalency Factors for Solving the Crash Frequency-Severity Dilemma: Case Study on South Korean Rural Roads

    OpenAIRE

    Oh, Jutaek; Washington, Simon; Lee, Dongmin

    2010-01-01

    Safety interventions (e.g. median barriers, photo enforcement) and road features (e.g. median type and width) can influence crash severities, crash frequencies, or both. Both dimensions—crash frequency and crash severity—are needed to obtain a full accounting of road safety. Extensive literature and common sense both dictate that all crashes are not ‘created’ equal—with fatalities costing society more than 1000 times the cost of property damage only crashes. Despite this glowing dis...

  7. Amphibious Aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — A brief self composed research article on Amphibious Aircrafts discussing their use, origin and modern day applications along with their advantages and...

  8. Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS experiment: design, execution and science overview

    Directory of Open Access Journals (Sweden)

    P. I. Palmer

    2013-02-01

    Full Text Available We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants using Aircraft and Satellites experiment, which has the overarching objective of understanding the chemical aging of airmasses that contain the emission products from seasonal boreal wildfires and how these airmasses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA over eastern Canada. The planned July 2010 deployment of the ARA was postponed by 12 months because of activities related to the dispersal of material emitted by the Eyjafjallajökull volcano. However, most other planned model and measurement activities, including ground-based measurements at the Dalhousie University Ground Station (DGS, enhanced ozonesonde launches, and measurements at the Pico Atmospheric Observatory in the Azores, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 included the same measurements, but included the ARA, special satellite observations and a more comprehensive measurement suite at the DGS. The high-frequency aircraft data provided a comprehensive snapshot of the pyrogenic plumes from wildfires. The coordinated ground-based and sonde data provided detailed but spatially-limited information that put the aircraft data into context of the longer burning season. We coordinated aircraft vertical profiles and overpasses of the NASA Tropospheric Emission Spectrometer and the Canadian Atmospheric Chemistry Experiment. These space-borne data, while less precise than other data, helped to relate the two-week measurement campaign to larger geographical and longer temporal scales. We interpret these data using a range of chemistry models: from a near-explicit gas-phase chemical mechanism, which tests out understanding of the underlying chemical mechanism, to regional and global 3-D models

  9. Predicting crash risk and identifying crash precursors on Korean expressways using loop detector data.

    Science.gov (United States)

    Kwak, Ho-Chan; Kho, Seungyoung

    2016-03-01

    In order to improve traffic safety on expressways, it is important to develop proactive safety management strategies with consideration for segment types and traffic flow states because crash mechanisms have some differences by each condition. The primary objective of this study is to develop real-time crash risk prediction models for different segment types and traffic flow states on expressways. The mainline of expressways is divided into basic segment and ramp vicinity, and the traffic flow states are classified into uncongested and congested conditions. Also, Korean expressways have irregular intervals between loop detector stations. Therefore, we investigated on the effect and application of the detector stations at irregular intervals for the crash risk prediction on expressways. The most significant traffic variables were selected by conditional logistic regression analysis which could control confounding factors. Based on the selected traffic variables, separate models to predict crash risk were developed using genetic programming technique. The model estimation results showed that the traffic flow characteristics leading to crashes are differed by segment type and traffic flow state. Especially, the variables related to the intervals between detector stations had a significant influence on crash risk prediction under the uncongested condition. Finally, compared with the single model for all crashes and the logistic models used in previous studies, the proposed models showed higher prediction performance. The results of this study can be applied to develop more effective proactive safety management strategies for different segment types and traffic flow states on expressways with loop detector stations at irregular intervals. PMID:26710266

  10. Crash Recovery for Embedded Main Memory Database

    Directory of Open Access Journals (Sweden)

    Fang Ye

    2012-10-01

    Full Text Available In the last years, the deployment of embedded real-time communication systems has increased dramatically. At the same time, the amount of data that needs to be managed by embedded real-time main memory databases is increasing, thus requiring an efficient data management. However, system crash will cause data loss in main memory, which will seriously affect the normal operation of the entire communication system. This paper introduces an algorithm of system crash recovery applied in main memory database of embedded real-time communication system. This paper expatiates the software architecture of SDR base station, the cause of crash occurring, and proposes the flash recovery algorithm using for system recovery. A main memory database using this algorithm has been applied in a real communication system——multimode SDR base station communication system.

  11. Transportation Institute releases findings on driver behavior and crash factors

    OpenAIRE

    Box, Sherri

    2006-01-01

    Driver inattention is the leading factor in most crashes and near-crashes, according to a landmark research report released today by the National Highway Traffic Safety Administration (NHTSA) and the Virginia Tech Transportation Institute (VTTI).

  12. Recession depression: mental health effects of the 2008 stock market crash.

    Science.gov (United States)

    McInerney, Melissa; Mellor, Jennifer M; Nicholas, Lauren Hersch

    2013-12-01

    Do sudden, large wealth losses affect mental health? We use exogenous variation in the interview dates of the 2008 Health and Retirement Study to assess the impact of large wealth losses on mental health among older U.S. adults. We compare cross-wave changes in wealth and mental health for respondents interviewed before and after the October 2008 stock market crash. We find that the crash reduced wealth and increased feelings of depression and use of antidepressant drugs, and that these effects were largest among respondents with high levels of stock holdings prior to the crash. These results suggest that sudden wealth losses cause immediate declines in subjective measures of mental health. However, we find no evidence that wealth losses lead to increases in clinically-validated measures of depressive symptoms or indicators of depression. PMID:24113241

  13. Collective Behavior of Stock Prices as a Precursor to Market Crash

    Science.gov (United States)

    Maskawa, J.

    We study precursors to the global market crash that occurred onall main stock exchanges throughout the world in October 2008 about three weeks after the bankruptcy of Lehman Brothers Holdings Inc. on 15 September. We examine the collective behavior of stock returns and analyze the market mode, which is a market-wide collective mode, with constituent issues of the FTSE 100 index listed on the London Stock Exchange. Before the market crash, a sharp rise in a measure of the collective behavior was observed. It was shown to be associated with news including the words ``financial crisis". They did not impact stock prices severely alone, but they exacerbated the pessimistic mood that prevailed among stock market participants. Such news increased after the Lehman shock preceding the market crash. The variance increased along with the cumulative amount of news according to a power law.

  14. Gender and Age Differences among Teen Drivers in Fatal Crashes

    OpenAIRE

    Swedler, David I.; Bowman, Stephen M.; Baker, Susan P.

    2012-01-01

    To identify age and gender differences among teen drivers in fatal crashes, we analyzed FARS data for 14,026crashes during 2007–2009. Compared with female teenagers, crashes of male teenagers were significantly more likely to involve BACs of 0.08% or more (21% vs. 12%), speeding (38% vs. 25%), reckless driving (17% vs. 14%), night driving (41% vs. 36%) and felony crashes (hit-and-run, homicide, or manslaughter) (8% vs. 6%) (all χ2 p

  15. Identification of Car Passengers with RFID for Automatic Crash Notification

    OpenAIRE

    Ouyang, Dongfang

    2009-01-01

    Automatic Crash Notification is a system designed to be used in a crash situation. When a crash occurs, the intelligent system is activated and automatically sends select crash details to the appropriate Emergency Medical Service Center. These details can be the position of the vehicle and the likely severity of the damage. Using the information, the medical treatment resources demanded for the accident is assessed at Emergency Center. Accordingly, first-aid facilities are promptly and proper...

  16. Influence of Cannabis on Fatal Traffic Crash: A Detailed Analysis

    OpenAIRE

    VAN ELSLANDE, Pierre; FOURNIER, Jean-Yves; Jaffard, Magali

    2012-01-01

    The influence of cannabis on traffic crashes is a growing concern. Experimental studies provide ample evidences of cannabis influence on psychomotor and cognitive performances. Epidemiological works describe the excess crash risk that this substance causes. And yet, this psychotropic drug influence in causing crashes is still at the centre of many discussions. The present analysis consists in exploiting crash data in detail to obtain a more precise understanding of the failures that drivers a...

  17. Gasoline Prices and Their Relationship to Drunk-Driving Crashes

    OpenAIRE

    Guangqing Chi; Xuan Zhou; Timothy McClure; Paul Gilbert; Arthur Cosby; Li Zhang; Angela Robertson; David Levinson

    2010-01-01

    This study investigates the relationship between changing gasoline prices and drunk-driving crashes. Specifically, we examine the effects of gasoline prices on drunk-driving crashes in Mississippi by age, gender, and race from 2004Ð2008, a period experiencing great fluctuation in gasoline prices. An exploratory visualization by graphs shows that higher gasoline prices are generally associated with fewer drunk-driving crashes. Higher gasoline prices depress drunk- driving crashes among younger...

  18. Aircraft Design

    Science.gov (United States)

    Bowers, Albion H. (Inventor); Uden, Edward (Inventor)

    2016-01-01

    The present invention is an aircraft wing design that creates a bell shaped span load, which results in a negative induced drag (induced thrust) on the outer portion of the wing; such a design obviates the need for rudder control of an aircraft.

  19. Aircraft Noise

    Science.gov (United States)

    Michel, Ulf; Dobrzynski, Werner; Splettstoesser, Wolf; Delfs, Jan; Isermann, Ullrich; Obermeier, Frank

    Aircraft industry is exposed to increasing public pressure aiming at a continuing reduction of aircraft noise levels. This is necessary to both compensate for the detrimental effect on noise of the expected increase in air traffic and improve the quality of living in residential areas around airports.

  20. Utilizing computed tomography scans for analysis of motorcycle helmets in real-world crashes - biomed 2011.

    Science.gov (United States)

    Loftis, Kathryn L; Moreno, Daniel P; Tan, Joshua; Gabler, Hampton C; Stitzel, Joel D

    2011-01-01

    In 2008, there were more than 5,000 motorcycle crash fatalities in the United States. Many states have motorcycle helmet laws that are meant to protect riders during a crash. After recruiting motorcycle occupants injured in crashes, a protocol was established to scan three different types of motorcycle helmets commonly worn (cap, ¾ shield, and full face shield) using a computed tomography (CT) scanner. The protocol developed was for a GE 64 slice PET/CT Discovery VCT scanner with axial images from anterior to posterior helmet acquired in helical mode. It had 512x512 resolution and the full face and ¾ face shield helmets were scanned with greater voxels in the axial plane compared to the skull cap helmets. New helmets were scanned as exemplary images for comparison with helmets involved in motorcycle crashes. After CT scans were gathered, three-dimensional reconstructions were made to visualize scratches and impacts to the exterior of the helmets. Initial work was also conducted in analyzing interior components, and a trend was seen in decreased thickness between the interior foam and shell with sides of the exterior helmet thought to have contacted roadside barriers or the ground during motorcycle crashes. These helmet analysis methods have been established, and will be used to investigate multiple motorcycle crashes in conjunction with occupant injuries and direct head impacts to improve helmet design and the understanding of head injuries. This work also establishes the basis for development of finite element models of three of the most common helmet types. PMID:21525626

  1. Pre-crash system validation with PRESCAN and VEHIL

    NARCIS (Netherlands)

    Gietelink, O.J.; Verburg, D.J.; Labibes, K.; Oostendorp, A.F.

    2004-01-01

    This paper presents the tools for design and validation of Pre-Crash Systems: the software tool PRE-crash SCenario ANalyzer (PRESCAN) and the VEhicle-Hardware-In-the-Loop (VEHIL) facility. PRESCAN allows to investigate a pre-crash scenario in simulation. This scenario can then be compared with tests

  2. 49 CFR 563.10 - Crash test performance and survivability.

    Science.gov (United States)

    2010-10-01

    ... CFR 571.208, Occupant crash protection, must comply with the requirements in subpart (c) of this... 49 Transportation 6 2010-10-01 2010-10-01 false Crash test performance and survivability. 563.10... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.10 Crash...

  3. Analysis of 86 fatal motorcycle frontal crashes in Chongqing, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hui; HUANG Wei; YANG Guang-yu; CHEN Rong; LIU Sheng-xiong; YU Yong-min; YIN Zhi-yong; WANG Zheng-guo

    2012-01-01

    Objective: To analyze the injuries of motorcyclists involved in fatal motorcycle frontal crashes.Methods: A survey group involving multi-discipline experts was built to randomly collect data on fatal motorcycle frontal collision accidents that occurred in Chongqing during 2006-2010.The sampled information included medical or autopsy reports,blood alcohol concentration (BAC)level,helmet use,accident witness,field sketch as well as field photos.The motorcyclist injuries were scored according to the Abbreviated Injury Scale (AIS) 2005.The involved riders with a BAC level≥20 mg/ml were attributed to alcohol use.Data were processed statistically with nonparametric test via software SPSS 11.0.Results:A total of 86 fatal motorcycle frontal crashes were sampled and further analyzed.The age of motorcyclists enrolled in this investigation showed nominal distribution and the middle-aged (30-39 years) occupied the highest percentage of fatalities.There were only 14 motorcyclists (16.3%) wearing helmets at the moment ofcollision.And 12.8% of these motorcyclist crashes were attributable to alcohol use.Impact injury was the main fatal cause,accounting for 72% of motorcyclist deaths,followed by tumbling injury (26%) and run-over (2%).Respectively 84%,22% and 19%of motorcyclists who sustained head,chest and abdominal trauma died.Extremity injury was the most frequently observed injury type.Conclusions: This investigation is helpful to build accident prevention programs and develop protection devices which may effectively mitigate injuries and prevent deaths following motorcycle frontal collision accidents.Further investigations on motorcycle collision accidents are still needed.

  4. Analyzing road design risk factors for run-off-road crashes in The Netherlands with crash prediction models.

    NARCIS (Netherlands)

    Petegem, J.W.H. van & Wegman, F.C.M.

    2014-01-01

    About 50% of all road traffic fatalities and 30% of all traffic injuries in The Netherlands take place on rural roads with a speed limit of 80 km/h. About 50% of these crashes are run-off-road (ROR) crashes. To reduce the number of crashes on this road type, attention should be put on improving the

  5. 国外控制机场飞机噪声影响的措施%Noise Impact Control Measures of Aircrafts in Foreign Airports

    Institute of Scientific and Technical Information of China (English)

    尹建坤; 赵仁兴; 田瑞丽; 马丽霞

    2015-01-01

    介绍了国外机场控制飞机噪声影响的主要做法。国际民航组织发行的《飞机噪声管理的平衡做法指导》主要是从减少噪声源,土地使用规划和管理,减噪运行程序和运行限制等方面控制噪声污染。美国采取的控制措施主要有做好航空规划和城市规划的协调发展,根据机场周边敏感点情况设计影响居民较少的飞行程序,并给出了机场噪声控制措施汇总。欧盟采取的控制措施是建立安静的空中交通系统,技术上需要有安静的飞机,低噪声程序和社会影响管理等。举例说明了目前国外几个机场采取的降噪措施。结合国外机场飞机噪声控制措施,提出了适合我国的飞机噪声控制措施建议。%The main approaches to control the impact of aircraft noise in foreign airports were introduced. The“Bal-ance approach guidance for aircraft noise management”by ICAO has provided the approaches for noise pollution control in the aspects of noise source reduction, land-use planning and management, noise abatement operational procedures and opera-tion restrictions, etc. In the United States, the main control measures are the balancing between aviation development plan-ning and urban development planning, designing the flight procedures with less affect on residents according to the distribu-tion of sensitive points around the airport, and summarizing the airport noise control measures. Control measure by the EU is to establish a quiet air traffic system, including the use of technically quiet aircrafts, low-noise flight procedures and social impact management. The noise reduction measures currently used by several foreign airports were illustrated. Summarizing the aircraft noise control measures in foreign airports, some aircraft noise control measures for domestic airports were sug-gested.

  6. Experimental Study of Dispersion and Deposition of Expiratory Aerosols in Aircraft Cabins and Impact on Infectious Disease Transmission

    DEFF Research Database (Denmark)

    To, G.N.S.; Wan, M.P.; Chao, C.Y.H.;

    2009-01-01

    The dispersion and deposition characteristics of polydispersed expiratory aerosols were investigated in an aircraft cabin mockup to study the transmission of infectious diseases. The airflow was characterized by particle image velocimetry (PIV) measurements. Aerosol dispersionwas measured...... of expiratory aerosols could be used to shed insights on some epidemiological observations on in-flight transmission of certain infectious diseases....

  7. Research on aircraft trailing vortex detection based on laser's multiplex information echo

    Science.gov (United States)

    Zhao, Nan-xiang; Wu, Yong-hua; Hu, Yi-hua; Lei, Wu-hu

    2010-10-01

    Airfoil trailing vortex is an important reason for the crash, and vortex detection is the basic premise for the civil aeronautics boards to make the flight measures and protect civil aviation's security. So a new method of aircraft trailing vortex detection based on laser's multiplex information echo has been proposed in this paper. According to the classical aerodynamics theories, the formation mechanism of the trailing vortex from the airfoil wingtip has been analyzed, and the vortex model of Boeing 737 in the taking-off phase has also been established on the FLUENT software platform. Combining with the unique morphological structure characteristics of trailing vortex, we have discussed the vortex's possible impact on the frequency, amplitude and phase information of laser echo, and expounded the principle of detecting vortex based on fusing this information variation of laser echo. In order to prove the feasibility of this detecting technique, the field experiment of detecting the vortex of civil Boeing 737 by laser has been carried on. The experimental result has shown that the aircraft vortex could be found really in the laser scanning area, and its diffusion characteristic has been very similar to the previous simulation result. Therefore, this vortex detection means based on laser's multiplex information echo was proved to be practicable relatively in this paper. It will provide the detection and identification of aircraft's trailing vortex a new way, and have massive research value and extensive application prospect as well.

  8. Vehicle dynamics and crash dynamics with minicomputer.

    NARCIS (Netherlands)

    Giavotto, V. Puccinelli, L. Borri, M. Edelman, A. & Heijer, T.

    1982-01-01

    The definition and the development of the VEDYAC system is given. Following a previous large experience concerning the simulation of crashes with safety barriers, a basic philosophy has been developed and the requirements of the VEDYAC project have been fixed. The main features of the VEDYAC project

  9. Syncope and Motor Vehicle Crash Risk

    DEFF Research Database (Denmark)

    Numé, Anna-Karin; Gislason, Gunnar; Christiansen, Christine B;

    2016-01-01

    IMPORTANCE: Syncope may have serious consequences for traffic safety. Current clinical guideline recommendations on driving following syncope are primarily based on expert consensus. OBJECTIVE: To identify whether there is excess risk of motor vehicle crashes among patients with syncope compared...... reference. RESULTS: The 41 039 patients with syncope had a median age of 66 years (interquartile range [IQR], 47-78 years); 51.0% were women; and 34.8% had cardiovascular disease. Through a median follow-up of 2.0 years (IQR, 0.8-3.3 years), 1791 patients with syncope (4.4%) had a motor vehicle crash, 78.......83 (95% CI, 1.74-1.91) after adjustment for age, sex, socioeconomic position, and relevant comorbidities and pharmacotherapy. Men had a relatively higher rate of motor vehicle crashes (RR, 1.91; 95% CI, 1.79-2.03) than women (RR, 1.74; 95% CI, 1.63-1.87). The excess risk of motor vehicle crashes...

  10. Motor Vehicle Crash Injuries PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2014-10-07

    This 60 second Public Service Announcement is based on the October 2014 CDC Vital Signs report. Motor vehicle crashes are costly and preventable. Learn what can be done to help prevent motor vehicle injuries.  Created: 10/7/2014 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 10/7/2014.

  11. Vital Signs-Motor Vehicle Crash Injuries

    Centers for Disease Control (CDC) Podcasts

    2014-10-07

    This podcast is based on the October 2014 CDC Vital Signs report. Motor vehicle crashes are costly and preventable. Learn what can be done to help prevent motor vehicle injuries.  Created: 10/7/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 10/7/2014.

  12. CRASH3: cosmological radiative transfer through metals

    CERN Document Server

    Graziani, L; Ciardi, B

    2012-01-01

    Here we introduce CRASH3, the latest release of the 3D radiative transfer code CRASH. In its current implementation CRASH3 integrates into the reference algorithm the code Cloudy to evaluate the ionisation states of metals, self-consistently with the radiative transfer through H and He. The feedback of the heavy elements on the calculation of the gas temperature is also taken into account, making of CRASH3 the first 3D code for cosmological applications which treats self-consistently the radiative transfer through an inhomogeneous distribution of metal enriched gas with an arbitrary number of point sources and/or a background radiation. The code has been tested in idealized configurations, as well as in a more realistic case of multiple sources embedded in a polluted cosmic web. Through these validation tests the new method has been proven to be numerically stable and convergent. We have studied the dependence of the results on a number of physical quantities such as the source characteristics (spectral range...

  13. Preliminary Study on Impact Resistances of Fiber Reinforced Concrete Applied Nuclear Power Plants

    International Nuclear Information System (INIS)

    Studies to improve the impact resistance depending upon design parameters for fiber reinforced concrete, such as type of fibers and application ratio, are in progress. Authors assessed first the impact resistance of concrete walls depending upon fiber types and missile impact velocities. The safety assessment of nuclear power plants against large civil aircraft crashes have been accomplished for normal concrete and fiber reinforced concretes in this study. Studies on the safety assessments on the nuclear power plants against large civil aircraft crashes are ongoing actively. As a step of evaluating the applicability of fiber reinforced concrete in means of ensuring more structural safety of the nuclear power plants against impact, the impact resistance for the 1% steel and 2% polyamide fiber reinforced concretes have been evaluated. For reactor containment building structures, it seem there is no impact resistance enhancement of fiber reinforced concrete applied to reactor containment building in the cases of impact velocity 150 m/sec considered in this study. However this results from the pre-stressing forces which introduce compressive stresses in concrete wall and dome section of reactor containment building. Nonetheless there may be benefits to apply fiber reinforced concrete to nuclear power plants. For double containment type reactor containment building, the outer structure is a reinforced concrete structure. The impact resistances for non pre-stressed cylindrical reactor containment buildings are enhanced by 23 to 47 % for 2 % polyamide fiber reinforced concretes and 1 % steel fiber reinforced concretes respectively. For other buildings such as auxiliary building, compound building and fuel storage building surrounding the reactor containment building, there are so many reinforced concrete walls which are anticipated some enhancements of impact resistance by using fiber reinforced concretes. And heavier or faster large civil aircraft impacts produce higher

  14. Behaviour of a spent fuel transport-storage cask during an airplane crash

    International Nuclear Information System (INIS)

    TRANSNUCLEAIRE has got an order for the design and manufacturing of dual purpose, transport and storage, casks for spent fuel.An original item of the qualification of the design of this cask, for the storage aspect, is the necessity to demonstrate the resistance to an air crash.The typical case taken into account for design is the crash of a military fighter (F16) with a total mass of 14600kg and an impact speed of 150ms-1. The demonstration of the ability of the cask to withstand this test is provided by both calculation and test.Two cases were considered. For the first one, the projectile hits the cask at the centre of the anti-crash lid. For the second one, it hits the cask in the plane of the closure system.The first step of the qualification is based on calculations performed with a code designed to study the effects of crashes. The aim of the calculations is, mainly, to determine the missile which has to be shot, and to select the worst orientation for the impact.To provide a full justification of the acceptability of the impact as concerned leaktightness, a test has been performed on a one-third scale model. It has shown that it was not altered by the impact.The paper provides a full description of the method of analysis, results of the numerical analysis, conclusion of the test and how the combination of calculation and test demonstrates the ability of the cask to withstand an airplane crash. ((orig.))

  15. Survivors’ experiences from a train crash

    Directory of Open Access Journals (Sweden)

    Rebecca Forsberg

    2011-11-01

    Full Text Available Rarely described are people's lived experiences from severe injury events such as train crashes. The number of train crashes named disasters with ≥10 killed and/or ≥100 nonfatally injured grows globally and the trend shows that more people survive these disasters today than did so in the past. This results in an increased number of survivors needing care. The aim of the study was to explore survivors’ experiences from a train crash. Narrative interviews were performed with 14 passengers 4 years after a train crash event. Qualitative content analysis was used to analyse the interviews. Experiences were captured in three main themes: (1 Living in the mode of existential threat describes how the survivors first lost control, then were thrown into a state of unimaginable chaos as they faced death. (2 Dealing with the unthinkable described how survivors restored control, the central role of others, and the importance of reconstructing the event to move forward in their processing. (3 Having cheated death shows how some became shackled by their history, whereas others overcame the haunting of unforgettable memories. Furthermore, the result shows how all experienced a second chance in life. Experiencing a train crash meant that the passengers experienced severe vulnerability and a threat to life and interdependence turned out to play a crucial role. Focusing on helping other passengers on site was one way to regain the loss of control and kept the chaos at bay. Family, friends, and fellow passengers turned out to be extremely important during the recovery process why such closeness should be promoted and facilitated.

  16. Impact studies at Winfrith

    International Nuclear Information System (INIS)

    Analytical and experimental studies of subsonic impacts on nuclear reactor plant structures have been in progress at Winfrith since 1977. These studies have examined the behaviour of concrete and metal structures under the impact of missiles typifying those derived either from the plant itself or from external sources, such as crashing aircraft. During 1986 the Winfrith programme was expanded to include studies of the behaviour of radioactive materials transport containers under impact conditions. This report initially describes the experimental facilities available for impact studies at Winfrith. These include both compressed air guns, capable of delivering payloads of up to 65 kg at sonic velocity or payloads up to 2 tonnes at speeds up to 45 ms-1, and drop test facilities for impact testing of models, up to full-scale radioactive materials transport flasks, at relatively low speeds. Supporting facilities include a small concrete manufacturing laboratory to produce concrete targets. Assessments of the resistance of concrete or metal structures to impact damage are performed using empirical or semi-empirical correlations, derived from data obtained in well-characterised experiments, or using structural dynamics finite element codes. The codes used by the analysts and the computing facilities available for impact analysis work are described. Finally the current programme of impact studies is reviewed, recent progress is summarised and future plans outlined. (author)

  17. Design of the Cross Section Shape of AN Aluminum Crash Box for Crashworthiness Enhancement of a CAR

    Science.gov (United States)

    Kim, S. B.; Huh, H.; Lee, G. H.; Yoo, J. S.; Lee, M. Y.

    This paper deals with the crashworthiness of an aluminum crash box for an auto-body with the various shapes of cross section such as a rectangle, a hexagon and an octagon. First, crash boxes with various cross sections were tested with numerical simulation to obtain the energy absorption capacity and the mean load. In case of the simple axial crush, the octagon shape shows higher mean load and energy absorption than the other two shapes. Secondly, the crash boxes were assembled to a simplified auto-body model for the overall crashworthiness. The model consists of a bumper, crash boxes, front side members and a sub-frame representing the behavior of a full car at the low speed impact. The analysis result shows that the rectangular cross section shows the best performance as a crash box which deforms prior to the front side member. The hexagonal and octagonal cross sections undergo torsion and local buckling as the width of cross section decreases while the rectangular cross section does not. The simulation result of the rectangular crash box was verified with the experimental result. The simulation result shows close tendency in the deformed shape and the load-displacement curve to the experimental result.

  18. Modeling the effects of AADT on predicting multiple-vehicle crashes at urban and suburban signalized intersections.

    Science.gov (United States)

    Chen, Chen; Xie, Yuanchang

    2016-06-01

    Annual Average Daily Traffic (AADT) is often considered as a main covariate for predicting crash frequencies at urban and suburban intersections. A linear functional form is typically assumed for the Safety Performance Function (SPF) to describe the relationship between the natural logarithm of expected crash frequency and covariates derived from AADTs. Such a linearity assumption has been questioned by many researchers. This study applies Generalized Additive Models (GAMs) and Piecewise Linear Negative Binomial (PLNB) regression models to fit intersection crash data. Various covariates derived from minor-and major-approach AADTs are considered. Three different dependent variables are modeled, which are total multiple-vehicle crashes, rear-end crashes, and angle crashes. The modeling results suggest that a nonlinear functional form may be more appropriate. Also, the results show that it is important to take into consideration the joint safety effects of multiple covariates. Additionally, it is found that the ratio of minor to major-approach AADT has a varying impact on intersection safety and deserves further investigations. PMID:26974024

  19. Full-scale crash test and FEM simulation of a crashworthy helicopter seat

    Institute of Scientific and Technical Information of China (English)

    HU Da-yong; ZHANG Xiang

    2012-01-01

    Crashworthy seat structure with considerable energy absorption capacity is a key component for aircraft to improve its crashworthiness and occupant survivability in emergencies. According to Federal Aviation Administration(FAA) regulations, seat performance must be certified by dynamic crash test which is quite expensive and time-consuming. For this reason, numerical simulation is a more efficient and economical approach to provide the possibility to assess seat performances and predict occupant responses. A numerical simulation of the crashworthy seat structure was presented and the results were also compared with the full-scale crash test data. In the numerical simulation, a full-scale three-dimensional finite element model of the seat/occupant structure was developed using a nonlinear and explicit dynamic finite element code LS-DYNA3D. Emphasis of the numerical simulation was on predicting the dynamic response of seat/occupant system,including the occupant motion which may lead to injuries,the occupant acceleration-time histories, and the energy absorbing behavior of the energy absorbers. The agreement between the simulation and the physical test suggestes that the developed numerical simulation can be a feasible substitute for the dynamic crash test.

  20. Aircraft Carriers

    DEFF Research Database (Denmark)

    Nødskov, Kim; Kværnø, Ole

    the majority of its foreign trade, as well as its oil imports, upon which the country is totally dependent. China therefore has good reasons for acquiring an aircraft carrier to enable it to protect its national interests. An aircraft carrier would also be a prominent symbol of China’s future status...... information is pieced together, then a picture is created of a Chinese aircraft carrier program, where Varyag will be made operational for training purposes. With this as the model, China will build a similar sized carrier themselves. If this project does become a reality, then it will take many years for...... Kuznetsov carrier. The SU-33 is, in its modernized version, technologically at the same level as western combat aircraft in both the offensive as well as the defensive roles. But Russia and China currently have an arms trade 6 dispute that is likely to prevent a deal, unless the dispute is resolved. As an...

  1. Driver inattention and driver distraction in serious casualty crashes: data from the Australian National Crash In-depth Study.

    Science.gov (United States)

    Beanland, Vanessa; Fitzharris, Michael; Young, Kristie L; Lenné, Michael G

    2013-05-01

    Driver inattention and driver distraction represent a major problem in road safety. Although both are believed to contribute to increased crash risk, there is currently limited reliable information on their role in crashes. The current study used in-depth data from the Australian National Crash In-depth Study to investigate the role of driver distraction and inattention in serious casualty crashes. The sample included 856 crashes from 2000 to 2011, in which at least one party was admitted to hospital due to crash-related injuries. Crashes were coded using a taxonomy of driver inattention that delineates five inattention subtypes: restricted attention, misprioritised attention, neglected attention, cursory attention, and diverted attention (distraction). Approximately 45% of crashes could not be coded due to insufficient information while in an additional 15% the participant indicated the "other driver was at fault" without specifying whether inattention was involved. Of the 340 remaining cases, most showed evidence of driver inattention (57.6%) or possible inattention (5.9%). The most common subtypes of inattention were restricted attention, primarily due to intoxication and/or fatigue, and diverted attention or distraction. The most common types of distraction involved voluntary, non-driving related distractions originating within the vehicle, such as passenger interactions. The current study indicates that a majority of serious injury crashes involve driver inattention. Most forms of inattention and distraction observed are preventable. This study demonstrates the feasibility of using in-depth crash data to investigate driver inattention in casualty crashes. PMID:23499981

  2. The impact of nitrogen oxides emissions from aircraft upon the atmosphere at flight altitudes—results from the aeronox project

    Science.gov (United States)

    Schumann, U.

    The AERONOX project investigated the emissions of nitrogen oxides (NO x) from aircraft engines and global air traffic at cruising altitudes, the resultant increase in NO x concentrations, and the effects on the composition of the atmosphere, in particular with respect to ozone formation in the upper troposphere and lower stratosphere. The project was structured into three subprojects: Engine exhaust emissions, physics and chemistry in the aircraft wake, and global atmospheric model simulations. A complementary program of work by aviation experts has provided detailed information on air traffic data which was combined with data on aircraft performance and emissions to produce a global emissions inventory. This summary gives an overview of the results of this project. Further details are given in the following papers of this issue and the final project report of 1995. The work resulted in improved predictive equations to determine NO x emissions at cruise conditions based on available data for aircraft/engine combinations, and NO x emission measurements on two engines in cruise conditions. This information was combined with a traffic database to provide a new global NO x emissions inventory. It was found that only minor chemical changes occur during the vortex regime of the emission plume; however, this result does not exclude the possibility of further changes in the dispersion phase. A variety of global models was set up to investigate the changes in NO x concentrations and photochemistry. Although aviation contributes only a small proportion (about 3%) of the total global NO x from all anthropogenic sources, the models show that aviation contributes a large fraction to the concentrations of NOX in the upper troposphere, in particular north of 30°N.

  3. Quantifying the Impact of BOReal Forest Fires on Tropospheric Oxidants Over the Atlantic Using Aircraft and Satellites (BORTAS) Experiment: Design, Execution, and Science Overview

    Science.gov (United States)

    Palmer, Paul I.; Parrington, Mark; Lee, James D.; Lewis, Alistair C.; Richard, Andrew R.; Bernath, Peter F.; Pawson, Steven; daSilva, Arlindo M.; Duck, Thomas J.; Waugh, David L.; Tarasick, Daivd W.; Andrews, Stephen; Aruffo, Eleonora; Bailey, Loren J.; Barrett, Lucy; Bauguitte, Stephan J.-B.; Curry, Kevin R.; DiCarlo, Piero; Chisholm, Lucy; Dan, Lin; Forster, Grant; Franklin, Jonathan E.; Gibson, Mark D.; Griffin, Debora; Moore, David P.

    2013-01-01

    We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of airmasses that contain the emission products from seasonal boreal wildfires and how these airmasses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada. The planned July 2010 deployment of the ARA was postponed by 12 months because of activities related to the dispersal of material emitted by the Eyjafjallaj¨okull volcano. However, most other planned model and measurement activities, including ground-based measurements at the Dalhousie University Ground Station (DGS), enhanced ozonesonde launches, and measurements at the Pico Atmospheric Observatory in the Azores, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 included the same measurements, but included the ARA, special satellite observations and a more comprehensive measurement suite at the DGS. Integrating these data helped us to describe pyrogenic plumes from wildfires on a wide spectrum of temporal and spatial scales. We interpret these data using a range of chemistry models, from a near-explicit gas-phase chemical mechanism to regional and global models of atmospheric transport and lumped chemistry. We also present an overview of some of the new science that has originated from this project.

  4. Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS experiment: design, execution and science overview

    Directory of Open Access Journals (Sweden)

    P. I. Palmer

    2013-07-01

    Full Text Available We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned July 2010 deployment of the ARA, which was postponed by 12 months due to UK-based flights related to the dispersal of material emitted by the Eyjafjallajökull volcano, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 involved the same atmospheric measurements, but included the ARA, special satellite observations and a more comprehensive ground-based measurement suite. The high-frequency aircraft data provided a comprehensive chemical snapshot of pyrogenic plumes from wildfires, corresponding to photochemical (and physical ages ranging from 45 sr 10 days, largely by virtue of widespread fires over Northwestern Ontario. Airborne measurements reported a large number of emitted gases including semi-volatile species, some of which have not been been previously reported in pyrogenic plumes, with the corresponding emission ratios agreeing with previous work for common gases. Analysis of the NOy data shows evidence of net ozone production in pyrogenic plumes, controlled by aerosol abundance, which increases as a function of photochemical age. The coordinated ground-based and sonde data provided detailed but spatially limited information that put the aircraft data into context of the longer burning season in the boundary layer. Ground

  5. Gender and Age Differences among Teen Drivers in Fatal Crashes.

    Science.gov (United States)

    Swedler, David I; Bowman, Stephen M; Baker, Susan P

    2012-01-01

    To identify age and gender differences among teen drivers in fatal crashes, we analyzed FARS data for 14,026crashes during 2007-2009. Compared with female teenagers, crashes of male teenagers were significantly more likely to involve BACs of 0.08% or more (21% vs. 12%), speeding (38% vs. 25%), reckless driving (17% vs. 14%), night driving (41% vs. 36%) and felony crashes (hit-and-run, homicide, or manslaughter) (8% vs. 6%) (all χ(2) p<0.001). Conversely, crashes of female teenagers were more likely to involve right angle ("t-bone") crashes (23% vs. 17%). Some crash characteristics associated with males and known to play a major role in crash causation also are more common in the youngest teenagers; for example, crashes of drivers age 15 or 16 were more likely than crashes of older teens to involve speeding or reckless driving. Crashes of drivers with BACs of 0.08% or higher increased with age in both genders. Some age effects differed by gender: for example, the proportion of crashes of female teens that involved speeding dropped from 38% to 22% between ages 15 and 19, while for males about 38% of crashes at each age involved speeding. The gender and age differences observed in teen drivers suggest opportunities for targeted driver training - for example, simulator training modules specifically tailored for male or female teenagers. Technology-based tools could also be developed to help parents to focus on the reckless driving tendencies of their sons. Insurance companies should consider ways to incentivize young males to drive more responsibly. PMID:23169121

  6. Earthquake Airbags, New Devices to Save Lives in Earthquakes, Tornados and Similar Disasters Resulting from Building Crashes

    Directory of Open Access Journals (Sweden)

    Amir Hashem Shahidi Bonjar

    2005-01-01

    Full Text Available Earthquake Airbag (EA is a new terminology being introduced for the earthquake literature of the world. According to literature surveys, this terminology has not been used previously. Based on many scientific reports, fatality rates are lower in vehicles equipped with airbags than unequipped ones. Accordingly, it was postulated that similar structures can be adopted in buildings to protect people and lower human casualties in building crashes. The data collected from simulation of collision-impact on fragile objects revealed that the safety advantage of airbags is that they can reduce impact injuries upon indoor people from falling debris in earthquakes and building crashes resulting from tornados, hurricanes or similar disasters.

  7. Explaining Differences in Crash and Injury Crash Outcomes in Red Light Camera Studies.

    Science.gov (United States)

    Langland-Orban, Barbara; Pracht, Etienne E; Large, John T; Zhang, Nanhua; Tepas, Joseph T

    2016-06-01

    Evaluations of red light camera (RLC) traffic safety programs have produced mixed results. Some conclude RLCs were associated with significant increases in motor vehicle crashes and injury crashes, whereas other research reports safety benefits. To understand the difference in findings, the present analysis assessed whether standards required for internal validity in quasi-experimental public health program evaluations were adhered to in frequently cited RLC analyses. Four evaluation standards were identified and used to assess the RLC analyses: lack of bias in the selection of both (a) treated sites and (b) comparison sites, (c) integration of relevant control variables in the analysis, and (d) full disclosure of results of the statistical analysis. Six leading RLC studies were then critiqued. Only two of the six studies adhered to the four standards and both concluded RLCs were associated with significant increases in crashes and injury or possible injury crashes. A third study reported an increase in fatal/injury crashes but did not test for statistical significance. Three studies reported equivocal findings; however, each failed to adhere to most standards. Differences in findings were attributed to the evaluation methods used. If implementing an RLC program, communities should use sound public health evaluation methods to assess effectiveness. PMID:25007792

  8. Modeling Situation Awareness and Crash Risk

    OpenAIRE

    Fisher, Donald L.; Strayer, David L.

    2014-01-01

    In this article we develop a model of the relationship between crash risk and a driver’s situation awareness. We consider a driver’s situation awareness to reflect the dynamic mental model of the driving environment and to be dependent upon several psychological processes including Scanning the driving environment, Predicting and anticipating hazards, Identifying potential hazards in the driving scene as they occur, Deciding on an action, and Executing an appropriate Response (SPIDER). Togeth...

  9. Can analyst predict stock market crashes?

    OpenAIRE

    Chong, Terence T. L.; Xiaolei Wang

    2013-01-01

    The frequency of financial market turmoil has been rising over the past two decades. While the incidence of market turmoil has increased, the performance of analysts during tumultuous times has not received much attention in the literature. This paper examines whether the accuracy of analyst forecasts on stock returns varies during tumultuous times. Our results indicate that analysts' forecast performance during stock market crashes drops significantly.

  10. Deleveraging, short sale constraints and market crash

    OpenAIRE

    Wu, Liang; Zhang, Lei; Fu, Zhiming

    2015-01-01

    In this paper, we develop a theory of market crashes resulting from a deleveraging shock. We consider two representative investors in a market holding different opinions about the public available information. The deleveraging shock forces the high confidence investors to liquidate their risky assets to pay back their margin loans. When short sales are constrained, the deleveraging shock creates a liquidity vacuum in which no trades can occur between the two representative investors until the...

  11. Motor Vehicle Crash Deaths PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2016-07-06

    This 60 second public service announcement is based on the July 2016 CDC Vital Signs report. In the U.S., about 90 people die in motor vehicle crashes each day and thousands more are injured, resulting in hundreds of millions of dollars in direct medical costs each year. Learn what you can do to stay safe.  Created: 7/6/2016 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 7/6/2016.

  12. The Stock Market Crashes of 1929 and 1987: Linking History and Personal Finance Education

    Science.gov (United States)

    Lopus, Jane S.

    2005-01-01

    This article discusses two twentieth-century stock market crashes: the crash of 1929 and the crash of 1987. When this material is presented to students, they see important parallels between the two historical events. But despite remarkable similarities in the severity and many other aspects of the two crashes, the crash of 1929 was followed by the…

  13. 41 CFR 102-34.295 - To whom do we send crash reports?

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false To whom do we send crash... MANAGEMENT Motor Vehicle Crash Reporting § 102-34.295 To whom do we send crash reports? Send crash reports as... agency directives. (b) If the motor vehicle is leased from GSA Fleet, report the crash to GSA...

  14. The structural integrity analysis of concrete containment vessels under external impacts

    International Nuclear Information System (INIS)

    This paper gives a three-dimensional dynamic finite element analysis of concrete containment vessels under impact loads. This analysis includes the non-linear behaviour of concrete, structural damping and cracking. A combination of solid isoparametric, panel and line elements representing vessel concrete, steel lining and prestressing tendons or conventional steel respectively is suggested. Three dimensional computer program DYCONT is developed which gives time dependent interactive calculations for stresses, deflections, cracks, reinforcement and suitable wall and dome thicknesses. An existing concrete containment vessel for PWR is examined under aircraft crash load. The analytical results are well compared with those available from the experimental model tests. (orig.)

  15. Development of SCR Aircraft takeoff and landing procedures for community noise abatement and their impact on flight safety

    Science.gov (United States)

    Grantham, W. D.; Smith, P. M.

    1980-01-01

    Piloted simulator studies to determine takeoff and landing procedures for a supersonic cruise transport concept that result in predicted community noise levels which meet current Federal Aviation Administration (FAA) standards are discussed. The results indicate that with the use of advanced procedures, the subject simulated aircraft meets the FAA traded noise levels during takeoff and landing utilizing average flight crew skills. The advanced takeoff procedures developed involved violating three of the current Federal Aviation Regulations (FAR) noise test conditions. These were: (1) thrust cutbacks at altitudes below 214 meters (700 ft); (2) thrust cutback level below those presently allowed; and (3) configuration change, other than raising the landing gear. It was not necessary to violate any FAR noise test conditions during landing approach. It was determined that the advanced procedures developed do not compromise flight safety. Automation of some of the aircraft functions reduced pilot workload, and the development of a simple head-up display to assist in the takeoff flight mode proved to be adequate.

  16. Signal analysis, modeling and simulation of vehicle crash dynamics

    OpenAIRE

    Midjena, Debela Yadeta; Muraspahic, Sanin

    2013-01-01

    Vehicle crash safety has been a strong point of interest for long time in many countries due to the reason that safety statistics show high fatality rate of vehicle occupants involved in road accidents. All vehicles which are going to appear on the road must go through several serious crash investigations to approve whether they conform to the relevant safety standards. There are large crash test facilities built by big companies for these operations. However, a wide and full-scal...

  17. Performing Network Level Crash Evaluation Using Skid Resistance

    OpenAIRE

    McCarthy, Ross James

    2015-01-01

    Evaluation of crash count data as a function of roadway characteristics allows Departments of Transportation to predict expected average crash risks in order to assist in identifying segments that could benefit from various treatments. Currently, the evaluation is performed using negative binomial regression, as a function of average annual daily traffic (AADT) and other variables. For this thesis, a crash study was carried out for the interstate, primary and secondary routes, in the...

  18. On the Fatal Crash Experience of Older Drivers

    OpenAIRE

    Kent, Richard; Henary, Basem; Matsuoka, Fumio

    2005-01-01

    This study describes the fatal crash experiences of older drivers. Data from two U.S. databases (NASS-CDS and FARS) were used. Several crash, vehicle, and occupant characteristics were compared across age groups, including vehicle type, crash direction (PDOF), severity (ΔV), and injured body region. A sub-set of 97 fatally injured drivers was chosen for a detailed case study. The mean travel speed, ΔV, and airbag deployment rate decreased significantly with age (p

  19. A Study into Impacts of Local Sound's Environment from Aircraft Noise Pollution%机场飞机噪声对区域声环境影响的研究

    Institute of Scientific and Technical Information of China (English)

    韩宝坤

    2011-01-01

    根据机场飞机噪声对周围敏感区域影响的状况,结合实测数据和环评预测结果,就飞机噪声对机场周围敏感区域的影响进行了分析研究,并提出了较为合理的飞机噪声控制建议参考。%The impacts on the local sound's environment by aircraft noise have been investigated, based on combined data sources from current sound environment measurement and estimates from environmental impacts projection, with special emphasis and considerations allowed to areas susceptible to aircraft noise disruption. Suggestions thus been put forward for further aircraft noise regulation.

  20. Automated Vehicle Crash Rate Comparison Using Naturalistic Data

    OpenAIRE

    Blanco, Myra; Atwood, Jon; Russell, Sheldon; Trimble, Tammy; McClafferty, Julie; Perez, Miguel

    2016-01-01

    This study assessed driving risk for the United States nationally and for the Google Self-Driving Car project. Driving safety on public roads was examined in three ways. The total crash rates for the Self-Driving Car and the national population were compared to (1) rates reported to the police, (2) crash rates for different types of roadways, and (3) scenarios that give rise to unreported crashes. First, crash rates from the Google Self-Driving Car project per million miles driven, broken dow...

  1. Aircraft cybernetics

    Science.gov (United States)

    1977-01-01

    The use of computers for aircraft control, flight simulation, and inertial navigation is explored. The man-machine relation problem in aviation is addressed. Simple and self-adapting autopilots are described and the assets and liabilities of digital navigation techniques are assessed.

  2. Enhanced FAA-Hybrid III dummy for aircraft occupant safety assessment

    NARCIS (Netherlands)

    Waagmeester, C.D.; Ratingen, M.R. van; Giavotto, V.; Notarnicola, L.; Goldner, S.

    2002-01-01

    Following an integral approach unique in aircraft safety, the European HeliSafe project aims to improve the survivability of helicopter crashes and to reduce the risk at injuries for occupants in cockpit and cabin. In the project, a modified FAA-Hybrid III is used for the baseline-, design- and conc

  3. Aircraft study of the impact of lake-breeze circulations on trace gases and particles during BAQS-Met 2007

    Directory of Open Access Journals (Sweden)

    K. L. Hayden

    2011-04-01

    Full Text Available High time-resolved aircraft data, concurrent surface measurements and air quality model simulations were explored to diagnose the processes influencing aerosol chemistry under the influence of lake-breeze circulations in a polluted region of southwestern Ontario, Canada. The analysis was based upon horizontal aircraft transects at multiple altitudes across an entire lake-breeze circulation. Air mass boundaries due to lake-breeze fronts were identified in the aircraft meteorological and chemical data, which were consistent with the frontal locations determined from surface analyses. Observations and modelling support the interpretation of a lake-breeze circulation where pollutants were lofted at a lake-breeze front, transported in the synoptic flow, caught in a downdraft over the lake, and then confined by onshore flow. The detailed analysis led to the development of conceptual models that summarize the complex 3-D circulation patterns and their interaction with the synoptic flow. The identified air mass boundaries, the interpretation of the lake-breeze circulation, and best estimates for air parcel circulation times in the lake-breeze circulation (1.2 to 3.0 h enabled formation rates of oxygenated organic aerosol (OOA/ΔCO and SO42− to be determined. The formation rate for OOA, relative to excess CO, was found to be 2.5–6.2 μg m−3 ppmv−1 h−1 and the SO42− formation rate was 1.8–4.6% h−1. The formation rates are enhanced relative to regional background rates implying that lake-breeze circulations are an important dynamic in the formation of SO42− and secondary organic aerosol. The presence of cumulus clouds associated with the lake-breeze fronts suggests that these enhancements could be due to cloud processes. Additionally, the effective confinement of pollutants along the shoreline may have limited pollutant dilution

  4. Aircraft study of the impact of lake-breeze circulations on trace gases and particles during BAQS-Met 2007

    Directory of Open Access Journals (Sweden)

    K. L. Hayden

    2011-10-01

    Full Text Available High time-resolved aircraft data, concurrent surface measurements and air quality model simulations were explored to diagnose the processes influencing aerosol chemistry under the influence of lake-breeze circulations in a polluted region of southwestern Ontario, Canada. The analysis was based upon horizontal aircraft transects conducted at multiple altitudes across an entire lake-breeze circulation. Air mass boundaries due to lake-breeze fronts were identified in the aircraft meteorological and chemical data, which were consistent with the frontal locations determined from surface analyses. Observations and modelling support the interpretation of a lake-breeze circulation where pollutants were lofted at a lake-breeze front, transported in the synoptic flow, caught in a downdraft over the lake, and then confined by onshore flow. The detailed analysis led to the development of conceptual models that summarize the complex 3-D circulation patterns and their interaction with the synoptic flow. The identified air mass boundaries, the interpretation of the lake-breeze circulation, and the air parcel circulation time in the lake-breeze circulation (3.0 to 5.0 h enabled formation rates of organic aerosol (OA/ΔCO and SO42− to be determined. The formation rate for OA (relative to excess CO in ppmv was found to be 11.6–19.4 μg m−3 ppmv−1 h−1 and the SO42− formation rate was 5.0–8.8% h−1. The formation rates are enhanced relative to regional background rates implying that lake-breeze circulations are an important dynamic in the formation of SO42− and secondary organic aerosol. The presence of cumulus clouds associated with the lake-breeze fronts suggests that these enhancements could be due to cloud processes. Additionally, the effective confinement of pollutants along the shoreline may have limited pollutant dilution leading to

  5. Identification and validation of a logistic regression model for predicting serious injuries associated with motor vehicle crashes.

    Science.gov (United States)

    Kononen, Douglas W; Flannagan, Carol A C; Wang, Stewart C

    2011-01-01

    A multivariate logistic regression model, based upon National Automotive Sampling System Crashworthiness Data System (NASS-CDS) data for calendar years 1999-2008, was developed to predict the probability that a crash-involved vehicle will contain one or more occupants with serious or incapacitating injuries. These vehicles were defined as containing at least one occupant coded with an Injury Severity Score (ISS) of greater than or equal to 15, in planar, non-rollover crash events involving Model Year 2000 and newer cars, light trucks, and vans. The target injury outcome measure was developed by the Centers for Disease Control and Prevention (CDC)-led National Expert Panel on Field Triage in their recent revision of the Field Triage Decision Scheme (American College of Surgeons, 2006). The parameters to be used for crash injury prediction were subsequently specified by the National Expert Panel. Model input parameters included: crash direction (front, left, right, and rear), change in velocity (delta-V), multiple vs. single impacts, belt use, presence of at least one older occupant (≥ 55 years old), presence of at least one female in the vehicle, and vehicle type (car, pickup truck, van, and sport utility). The model was developed using predictor variables that may be readily available, post-crash, from OnStar-like telematics systems. Model sensitivity and specificity were 40% and 98%, respectively, using a probability cutpoint of 0.20. The area under the receiver operator characteristic (ROC) curve for the final model was 0.84. Delta-V (mph), seat belt use and crash direction were the most important predictors of serious injury. Due to the complexity of factors associated with rollover-related injuries, a separate screening algorithm is needed to model injuries associated with this crash mode. PMID:21094304

  6. Risk assessment of aircraft accidents anywhere near an airport

    International Nuclear Information System (INIS)

    This work analyzes the more suitable areas to build new facilities, taking into account the conditions imposed by an airport located nearby. Initially, it describes the major characteristics of the airport. Then, the restrictions imposed to ensure the normal operation of the aircraft are analyzed. Following, there is a summary of the evolution of studies of aircraft accidents at nuclear facilities. In the second part, three models of aircraft crash probabilities are presented, all of them developed in the U.S.A, each with an increasing level of complexity in modeling the likelihood of accidents. The first model is the 'STD-3014' Department of Energy (DOE), the second is the 'ACRAM'(Aircraft Crash Risk Assessment Methodology) prepared by the 'Lawrence Livermore National Laboratory'(LLNL) and finally the more advanced 'ACRP-3', produced by the 'Transportation Research Board'. The results obtained with the three models establish that the risks imposed on the airport vicinity, remain low due to the improvement and innovation in the aircraft's safety, reducing the risk margin for the location of new nuclear facilities near an airport. (author)

  7. 77 FR 29247 - Federal Motor Vehicle Safety Standards; Occupant Crash Protection

    Science.gov (United States)

    2012-05-17

    ... Standards; Occupant Crash Protection AGENCY: National Highway Traffic Safety Administration (NHTSA... technical amendments to Federal Motor Vehicle Safety Standard (FMVSS) No. 208, Occupant Crash Protection... requirements for pressure vessels and explosive devices used in occupant crash protection systems, such as...

  8. Barrage balloons against aircraft threat: A well proven concept revisited

    International Nuclear Information System (INIS)

    Since the event of September 11, 2001 in New York City, many people started to speculate that the same type of attack could in future be brought against other installations. Indeed, the U.S. Nuclear Regulatory Commission decided to require for future plants to assess their resistance to the impact of a large civil airliner. Nuclear plant control authorities of other countries decided in a similar direction. The solutions to the technical problem is usually pursued in the direction of a reinforcement of external plant structures and, in some case, they may not be sufficient. Other solutions of more psychological nature have also been adopted. This paper aims at the demonstration that the use of barrage balloons, already adopted with success in both World Wars and also occasionally after these events, can afford a satisfactory solution to the protection problem at a reasonable cost. This solution is also applicable to existing plants. The history of barrage balloons is summarized. Modern technology offers electronic devices capable to detect in time an approaching threat and the paper describes a new barrage system based also on such new possibilities. If the aircraft crash problem is a real one or not for the next years, nobody knows for sure; however some considerations should be kept in mind: ·The fact that an accident of this kind 'anywhere' is an accident 'everywhere' as usual; ·The extremely uncertain political outlook worldwide, the peculiarities of the oil market and the possible nuclear renaissance.

  9. Injury Mechanisms and Severity in Narrow Offset Frontal Impacts

    OpenAIRE

    Pintar, Frank A.; Yoganandan, Narayan; Maiman, Dennis J.

    2008-01-01

    Current standard frontal crash tests include full frontal or 40% offset. Frontal impacts with offsets less than 40% and corner impacts have received little attention. Because of the limited engagement of vehicle structures that would permit less energy dissipation, these crashes have the potential for severe trauma to the near-side occupant. Narrow offset and corner-impact crashes under a frontal impact classification were analyzed using data obtained from the United States Department of Tran...

  10. Realizing stock market crashes: stochastic cusp catastrophe model of returns under time-varying volatility

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Kukačka, Jiří

    2015-01-01

    Roč. 15, č. 6 (2015), s. 959-973. ISSN 1469-7688 R&D Projects: GA ČR GA402/09/0965; GA ČR GA13-32263S EU Projects: European Commission 612955 - FINMAP Institutional support: RVO:67985556 Keywords : Stochastic cusp catastrophe model * Realized volatility * Bifurcations * Stock market crash Subject RIV: AH - Economics Impact factor: 0.653, year: 2014 http://library.utia.cas.cz/separaty/2014/E/barunik-0434202.pdf

  11. Matching or Crashing? Personality-based Team Formation in Crowdsourcing Environments

    OpenAIRE

    Lykourentzou, Ioanna; Antoniou, Angeliki; Naudet, Yannick

    2015-01-01

    "Does placing workers together based on their personality give better performance results in cooperative crowdsourcing settings, compared to non-personality based crowd team formation?" In this work we examine the impact of personality compatibility on the effectiveness of crowdsourced team work. Using a personality-based group dynamics approach, we examine two main types of personality combinations (matching and crashing) on two main types of tasks (collaborative and competitive). Our experi...

  12. Modelling physiological features of Human body behavior in car crash simulations

    OpenAIRE

    Behr, M.; GODIO,Y; LLARI,M; Brunet, C

    2007-01-01

    Human numerical models are widely used to investigate injury mechanisms involved in car crash configurations. One limitation of these models is linked to the time dependency of biological tissues mechanical properties, as a result of various physiological modifications. To answer this limitation, we present one possible approach to evaluate the influence of internal body pressures (mainly resulting from breathing) on the result of a frontal impact, by modelling main muscles responsible for re...

  13. Full-Scale Crash Test of a MD-500 Helicopter with Deployable Energy Absorbers

    Science.gov (United States)

    Kellas, Sotiris; Jackson, Karen E.; Littell, Justin D.

    2010-01-01

    A new externally deployable energy absorbing system was demonstrated during a full-scale crash test of an MD-500 helicopter. The deployable system is a honeycomb structure and utilizes composite materials in its construction. A set of two Deployable Energy Absorbers (DEAs) were fitted on the MD-500 helicopter for the full-scale crash demonstration. Four anthropomorphic dummy occupants were also used to assess human survivability. A demonstration test was performed at NASA Langley's Landing and Impact Research Facility (LandIR). The test involved impacting the helicopter on a concrete surface with combined forward and vertical velocity components of 40-ft/s and 26-ft/s, respectively. The objectives of the test were to evaluate the performance of the DEA concept under realistic crash conditions and to generate test data for validation of dynamic finite element simulations. Descriptions of this test as well as other component and full-scale tests leading to the helicopter test are discussed. Acceleration data from the anthropomorphic dummies showed that dynamic loads were successfully attenuated to within non-injurious levels. Moreover, the airframe itself survived the relatively severe impact and was retested to provide baseline data for comparison for cases with and without DEAs.

  14. CRASH SAFETY OF A TYPICAL BAY TABLE IN A RAILWAY VEHICLE

    Directory of Open Access Journals (Sweden)

    Emmanuel MATSIKA

    2015-12-01

    Full Text Available Increasingly, urban and high speed trains are incorporating tables (workstations as common railway vehicle interior furniture because passengers prefer seating by bay tables. Among table design characteristics, the most challenging is meeting crashworthiness requirements. Past accident data and sled test results have shown that in the event of railway vehicle frontal impact, occupants located in the bay seating are exposed to chest and abdominal injuries upon contact with tables resulting from secondary collision. In some cases tables have tended to be structurally weak; they easily detach from the side walls and/or floor mounting. Subsequently these become unguided missiles that strike occupants, resulting in injuries. This paper presents an analysis of the crash performance of a typical bay table. The results provide some understanding of the table’s crash safety, giving an indication of its impact aggression. Table materials are characterised using quasi-static compressive tests. In addition, experimental dynamic (impact tests are conducted using a pendulum representing a body block (mass. The results provide information about the possible loading of the table on the occupant in the event of a crash. Contact forces are compared with chest and abdominal injury tolerance thresholds to infer the collision injury potential. Recommendations are then made on design of bay tables to meet the “functional-strength-and-safety balance”.

  15. Sawtooth crashes at high beta on JET

    Energy Technology Data Exchange (ETDEWEB)

    Alper, B.; Huysmans, G.T.A.; Sips, A.C.C. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Nave, M.F.F. [Universidade Tecnica, Lisbon (Portugal). Inst. Superior Tecnico

    1994-07-01

    The sawtooth crashes on JET display features which depend on beta. The main observation is a transient bulging of flux surfaces (duration inferior to 30 microsec.), which is predominantly on the low field side and extends to larger radii as beta increases. This phenomenon reaches the plasma boundary when beta{sub N} exceeds 0.5 and in these cases is followed by an ELM within 50 microsec. These sawtooth/ELM events limit plasma performance. Modelling of mode coupling shows qualitative agreement between observations of the structure of the sawtooth precursor and the calculated internal kink mode at high beta. (authors). 6 refs., 5 figs.

  16. Data Mining on Crash Simulation Data

    OpenAIRE

    Kuhlmann, A.; Vetter, R. -M.; Luebbing, Ch.; Thole, C. -A.

    2005-01-01

    The work presented in this paper is part of the cooperative research project AUTO-OPT carried out by twelve partners from the automotive industries. One major work package concerns the application of data mining methods in the area of automotive design. Suitable methods for data preparation and data analysis are developed. The objective of the work is the re-use of data stored in the crash-simulation department at BMW in order to gain deeper insight into the interrelations between the geometr...

  17. Mechanisms of injury in automobile crashes.

    Science.gov (United States)

    Huelke, D F

    1972-02-01

    The only way to determine the causes of injury in automobile collisions is through examination of data collected in detailed investigation of crashes. Such data were gathered from a ten-year study of collisions that caused injury to the occupants of the cars. In a comparison of injuries in the newer model automobiles-vehicles equipped with the safety features-with those in older model cars not equipped with the present-day occupant protection devices, significant reduction in injury severity was noted. PMID:5059662

  18. Injury Severity of Motorcycle Riders Involved in Traffic Crashes in Hunan, China: A Mixed Ordered Logit Approach.

    Science.gov (United States)

    Chang, Fangrong; Li, Maosheng; Xu, Pengpeng; Zhou, Hanchu; Haque, Md Mazharul; Huang, Helai

    2016-01-01

    Issues related to motorcycle safety in China have not received enough research attention. As such, the causal relationship between injury outcomes of motorcycle crashes and potential risk factors remains unknown. This study intended to investigate the injury risk of motorcyclists involved in road traffic crashes in China. To account for the ordinal nature of response outcomes and unobserved heterogeneity, a mixed ordered logit model was employed. Given that the crash occurrence process is different between intersections and non-intersections, separate models were developed for these locations to independently estimate the impacts of various contributing factors on motorcycle riders' injury severity. The analysis was based on the police-reported crash dataset obtained from the Traffic Administration Bureau of Hunan Provincial Public Security Ministry. Factors associated with a substantially higher probability of fatalities and severe injuries included motorcycle riders older than 60 years, the absence of helmets, motorcycle riders identified to be equal duty, and when a motorcycle collided with a heavy vehicle during the night time without lighting. Crashes occurred along county roads with curve and slope alignment or at regions with higher GDP were associated with an elevated risk of fatality of motorcycle riders, while unsignalized intersections were related to less severe injuries. Findings of this study are beneficial in forming several targeted countermeasures for motorcycle safety in China, including designing roads with appropriate road delineation and street lighting, strict enforcement for speeding and red light violations, promoting helmet usage, and improving the conspicuity of motorcyclists. PMID:27428987

  19. Injury Severity of Motorcycle Riders Involved in Traffic Crashes in Hunan, China: A Mixed Ordered Logit Approach

    Directory of Open Access Journals (Sweden)

    Fangrong Chang

    2016-07-01

    Full Text Available Issues related to motorcycle safety in China have not received enough research attention. As such, the causal relationship between injury outcomes of motorcycle crashes and potential risk factors remains unknown. This study intended to investigate the injury risk of motorcyclists involved in road traffic crashes in China. To account for the ordinal nature of response outcomes and unobserved heterogeneity, a mixed ordered logit model was employed. Given that the crash occurrence process is different between intersections and non-intersections, separate models were developed for these locations to independently estimate the impacts of various contributing factors on motorcycle riders’ injury severity. The analysis was based on the police-reported crash dataset obtained from the Traffic Administration Bureau of Hunan Provincial Public Security Ministry. Factors associated with a substantially higher probability of fatalities and severe injuries included motorcycle riders older than 60 years, the absence of helmets, motorcycle riders identified to be equal duty, and when a motorcycle collided with a heavy vehicle during the night time without lighting. Crashes occurred along county roads with curve and slope alignment or at regions with higher GDP were associated with an elevated risk of fatality of motorcycle riders, while unsignalized intersections were related to less severe injuries. Findings of this study are beneficial in forming several targeted countermeasures for motorcycle safety in China, including designing roads with appropriate road delineation and street lighting, strict enforcement for speeding and red light violations, promoting helmet usage, and improving the conspicuity of motorcyclists.

  20. Injury Severity of Motorcycle Riders Involved in Traffic Crashes in Hunan, China: A Mixed Ordered Logit Approach

    Science.gov (United States)

    Chang, Fangrong; Li, Maosheng; Xu, Pengpeng; Zhou, Hanchu; Haque, Md. Mazharul; Huang, Helai

    2016-01-01

    Issues related to motorcycle safety in China have not received enough research attention. As such, the causal relationship between injury outcomes of motorcycle crashes and potential risk factors remains unknown. This study intended to investigate the injury risk of motorcyclists involved in road traffic crashes in China. To account for the ordinal nature of response outcomes and unobserved heterogeneity, a mixed ordered logit model was employed. Given that the crash occurrence process is different between intersections and non-intersections, separate models were developed for these locations to independently estimate the impacts of various contributing factors on motorcycle riders’ injury severity. The analysis was based on the police-reported crash dataset obtained from the Traffic Administration Bureau of Hunan Provincial Public Security Ministry. Factors associated with a substantially higher probability of fatalities and severe injuries included motorcycle riders older than 60 years, the absence of helmets, motorcycle riders identified to be equal duty, and when a motorcycle collided with a heavy vehicle during the night time without lighting. Crashes occurred along county roads with curve and slope alignment or at regions with higher GDP were associated with an elevated risk of fatality of motorcycle riders, while unsignalized intersections were related to less severe injuries. Findings of this study are beneficial in forming several targeted countermeasures for motorcycle safety in China, including designing roads with appropriate road delineation and street lighting, strict enforcement for speeding and red light violations, promoting helmet usage, and improving the conspicuity of motorcyclists. PMID:27428987

  1. Crash-Induced Vibration and Safety Assessment of Breakaway-Type Post Structures Made of High Anticorrosion Steels

    Directory of Open Access Journals (Sweden)

    Sang-Youl Lee

    2016-01-01

    Full Text Available This study deals with car crash effects and passenger safety assessment of post structures with breakaway types using high performance steel materials. To disperse the impact force when a car crashes into a post, the post could be designed with a breakaway feature. In this study, we used a new high anticorrosion steel for the development of advanced breakaways. Based on the improved Cowper-Symonds model, specific physical properties to the high anticorrosion steel were determined. In particular, the complex mechanism of breakaways was studied using various parameters. The parametric studies are focused on the various effects of car crash on the structural performance and passenger safety of breakaway-type posts. The combined effects of using different steel materials on the dynamic behavers are also investigated.

  2. Analyzing angle crashes at unsignalized intersections using machine learning techniques.

    Science.gov (United States)

    Abdel-Aty, Mohamed; Haleem, Kirolos

    2011-01-01

    A recently developed machine learning technique, multivariate adaptive regression splines (MARS), is introduced in this study to predict vehicles' angle crashes. MARS has a promising prediction power, and does not suffer from interpretation complexity. Negative Binomial (NB) and MARS models were fitted and compared using extensive data collected on unsignalized intersections in Florida. Two models were estimated for angle crash frequency at 3- and 4-legged unsignalized intersections. Treating crash frequency as a continuous response variable for fitting a MARS model was also examined by considering the natural logarithm of the crash frequency. Finally, combining MARS with another machine learning technique (random forest) was explored and discussed. The fitted NB angle crash models showed several significant factors that contribute to angle crash occurrence at unsignalized intersections such as, traffic volume on the major road, the upstream distance to the nearest signalized intersection, the distance between successive unsignalized intersections, median type on the major approach, percentage of trucks on the major approach, size of the intersection and the geographic location within the state. Based on the mean square prediction error (MSPE) assessment criterion, MARS outperformed the corresponding NB models. Also, using MARS for predicting continuous response variables yielded more favorable results than predicting discrete response variables. The generated MARS models showed the most promising results after screening the covariates using random forest. Based on the results of this study, MARS is recommended as an efficient technique for predicting crashes at unsignalized intersections (angle crashes in this study). PMID:21094345

  3. Annoyance and acceptability judgements of noise produced by three types of aircraft by residents living near JFK Airport

    Science.gov (United States)

    Borsky, P. N.

    1974-01-01

    A random sample of selected communities near JFK Airport were interviewed. Subsamples, with differing feelings of fear of aircraft crashes and different locations of residence were invited to participate in a laboratory experiment. The subjects were exposed to tape recordings of simulated flyovers of aircraft in approach and departure operations at nominal distances from the airport. The subjects judged the extent of noise annoyance and acceptability of the aircraft noises. Results indicate that level of noise is most significant in affecting annoyance judgements. Subjects with feelings of high fear report significantly more annoyance and less acceptability of aircraft noise than subjects with feelings of low fear.

  4. Automated dimensional inspection of cars in crash tests with digital photogrammetry

    Science.gov (United States)

    Beyer, Horst A.

    1991-09-01

    Changes in the shape of cars due to impact in crash tests are determined from the deformation vectors of points located in specific positions on the car. The coordinates of these points are measured before as well as after the test. Costs and measurement time can be significantly reduced by automated dimensional inspection with digital photogrammetry. This paper reports on a pilot test in which the measurement of a car prepared for a crash test was performed under practical conditions. It was shown that an accuracy of 1 mm in each coordinate axis within a measurement volume of 5 X 2 X 2 m3 can be achieved under factory- floor conditions with low-cost CCD cameras. A high level of automation and robustness was demonstrated. The measurements were performed in a very short time with model-driven techniques.

  5. Spatiotemporal and random parameter panel data models of traffic crash fatalities in Vietnam.

    Science.gov (United States)

    Truong, Long T; Kieu, Le-Minh; Vu, Tuan A

    2016-09-01

    This paper investigates factors associated with traffic crash fatalities in 63 provinces of Vietnam during the period from 2012 to 2014. Random effect negative binomial (RENB) and random parameter negative binomial (RPNB) panel data models are adopted to consider spatial heterogeneity across provinces. In addition, a spatiotemporal model with conditional autoregressive priors (ST-CAR) is utilised to account for spatiotemporal autocorrelation in the data. The statistical comparison indicates the ST-CAR model outperforms the RENB and RPNB models. Estimation results provide several significant findings. For example, traffic crash fatalities tend to be higher in provinces with greater numbers of level crossings. Passenger distance travelled and road lengths are also positively associated with fatalities. However, hospital densities are negatively associated with fatalities. The safety impact of the national highway 1A, the main transport corridor of the country, is also highlighted. PMID:27294863

  6. Lumbar load attenuation for rotorcraft occupants using a design methodology for the seat impact energy-absorbing system

    Science.gov (United States)

    Moradi, Rasoul; Beheshti, Hamid; Lankarani, Hamid

    2012-12-01

    Aircraft occupant crash-safety considerations require a minimum cushion thickness to limit the relative vertical motion of the seat-pelvis during high vertical impact loadings in crash landings or accidents. In military aircraft and helicopter seat design, due to the potential for high vertical accelerations in crash scenarios, the seat system must be provided with an energy absorber to attenuate the acceleration level sustained by the occupants. Because of the limited stroke available for the seat structure, the design of the energy absorber becomes a trade-off problem between minimizing the stroke and maximizing the energy absorption. The available stroke must be used to prevent bottoming out of the seat as well as to absorb maximum impact energy to protect the occupant. In this study, the energy-absorbing system in a rotorcraft seat design is investigated using a mathematical model of the occupant/seat system. Impact theories between interconnected bodies in multibody mechanical systems are utilized to study the impact between the seat pan and the occupant. Experimental responses of the seat system and the occupant are utilized to validate the results from this study for civil and military helicopters according to FAR 23 and 25 and MIL-S-58095 requirements. A model for the load limiter is proposed to minimize the lumbar load for the occupant by minimizing the relative velocity between the seat pan and the occupant's pelvis. The modified energy absorber/load limiter is then implemented for the seat structure so that it absorbs the energy of impact in an effective manner and below the tolerable limit for the occupant in a minimum stroke. Results show that for a designed stroke, the level of occupant lumbar spine injury would be significantly attenuated using this modified energy-absorber system.

  7. Simulation of loading conditions for a type A package containing Americium-241 involved in an airplane crash at Detroit Metro Airport in January 1983

    International Nuclear Information System (INIS)

    On January 11, 1983, a United Airlines DC-8F cargo aircraft crashed shortly after takeoff from Detroit Metro Airport. A lower rear cargo pit had a type A package containing 10,000 241Am solid-form sources, each of 1.5-μCi strength, used in smoke detectors. Although burned and somewhat battered, the 1-gal metal can holding all these sources was recovered completely intact with no release of radioactive material to the environment or loss of any sources. This report describes Lawrence Livermore National Laboratory's attempt to reconstruct, as closely as practical, the mechanical and thermal environments experienced by this can during and immediately after the accident. Mechanical loading of the metal can in a shipping carton was simulated by impacts from a 16-lb pendulum mass falling through vertical displacements of up to 6 ft. Internal damage ranged from imperceptible to sufficient to demolish internal plastic jars and to produce major deformation of the metal can. The thermal environment was best reproduced by the simple burning of the outer shipping carton. 6 references, 27 figures

  8. APPLICATION FOR AIRCRAFT TRACKING

    OpenAIRE

    Ostroumov, Ivan; Kuz’menko, Natalia

    2011-01-01

    Abstract. In the article the important problems of software development for aircraft tracking have beendiscussed. Position reports of ACARS have been used for aircraft tracking around the world.An algorithm of aircraft coordinates decoding and visualization of aircraft position on the map has beenrepresented.Keywords: ACARS, aircraft, internet, position, software, tracking.

  9. Strategic Noise Mapping of Herakleion: The Aircraft Noise Impact as a factor of the Int. Airport relocation

    Directory of Open Access Journals (Sweden)

    Vogiatzis Konstantinos

    2014-09-01

    Full Text Available In the framework of the European Directive 2002/49/EC, the city of Herakleion in Crete Island (Greece recently completed (2013 its Strategic Noise Map (SNM and relevant Noise Action Plan (NAP. Strategic noise mapping and action plans are important tools to define the main strategies to reduce noise exposure of residents and introduce and preserve "quite zones". Within this framework and as a part of the Herakleion city Strategic Noise Mapping general a specific analysis was introduced in the urban area of Alikarnassos (east part of the city adjacent to the International Airport “Nikos Kazantzakis”. The 2nd biggest airport in Greece, airport is proposed to be relocated in Kastelli area (some 37 km south of the Herakleion city centre, far away from dense populated areas, within the next decade but in the mean time, air traffic (take of, taxi and landing procedures, especially during the extended spring and summer period, are affecting the city. This paper analyzes the extended acoustic measurement monitoring program and the modelling of environmental noise levels within the city’s SNM introducing - state of the art - qualitative surveys on the sound perception and noise annoyance by the residents as well as in depth analysis of the urban and architectural tissue. All these results have been transcribed in several maps introducing a very comprehensive evaluation tool towards an efficient noise action plan leading to the eventual relocation of the airport. This paper presents the main results of this research aiming to the evaluation of the inffluence at the inhabitants’ sonic comfort from aircraft operation.

  10. Countermeasures for Reducing Alcohol-Related Crashes.

    Science.gov (United States)

    Voas, R B

    2000-01-01

    Programs to prevent alcohol-related crashes occur at several levels. Although most of the public thinks of drunk-driving prevention only in terms of the criminal justice system, much can be done to prevent alcohol-related highway deaths before the drinking-and-driving offender gets on the road. In recent years, the field of alcohol safety has merged with the area of public health concerned with preventing alcohol- and drug-related traumatic injury and death. This paper provides an overview of the status of road safety programs directed at reducing impaired driving. It covers ten topics falling into the three levels of prevention: primary programs to reduce alcohol consumption; secondary programs to prevent driving after drinking; and tertiary programs to prevent recidivism among convicted drinking drivers. PMID:26256029

  11. Impact load time histories for viscoelastic missiles

    International Nuclear Information System (INIS)

    Generation of the impact load time history at the contact point between a viscoelastic missile and its targets is presented. In the past, in the case of aircraft striking containment shell structure, the impact load history was determined on the basis of actual measurements by subjecting a rigid wall to aircraft crash. The effects of elastic deformation of the target upon the impact load time history is formulated in this paper. The missile is idealized by a linear mass-spring-dashpot combination using viscoelastic models. These models can readily be processed taking into account the elastic as well as inelastic deformations of the missiles. The target is assumed to be either linearly elastic or rigid. In the case of the linearly elastic target, the normal mode theory is used to express the time-dependent displacements of the target which is simulated by lumped masses, elastic properties and dashpots in discrete parts. In the case of Maxwell viscoelastic model, the time-dependent displacements of the missile and the target are given in terms of the unknown impact load time history. This leads to an integral equation which may be solved by Laplace transformation. The normal mode theory is provided. Examples are given for bricks with viscoelastic materials as missiles against a rigid target. (Auth.)

  12. Bayesian log-periodic model for financial crashes

    DEFF Research Database (Denmark)

    Rodríguez-Caballero, Carlos Vladimir; Knapik, Oskar

    2014-01-01

    This paper introduces a Bayesian approach in econophysics literature about financial bubbles in order to estimate the most probable time for a financial crash to occur. To this end, we propose using noninformative prior distributions to obtain posterior distributions. Since these distributions...... part of the study, we analyze a well-known example of financial bubble – the S&P 500 1987 crash – to show the usefulness of the three methods under consideration and crashes of Merval-94, Bovespa-97, IPCMX-94, Hang Seng-97 using the simplest method. The novelty of this research is that the Bayesian...

  13. Projecting Fatalities in Crashes Involving Older Drivers, 2000-2025

    Energy Technology Data Exchange (ETDEWEB)

    Hu, P.S.

    2001-03-23

    As part of this research effort, we developed a new methodology for projecting elderly traffic crash fatalities. This methodology separates exposure to crashes from crash risk per se, and further divides exposure into two components, the number of miles driven and the likelihood of being a driver. This component structure permits conceptually different determinants of traffic fatalities to be projected separately and has thorough motivation in behavioral theory. It also permits finer targeting of particular aspects of projections that need improvement and closer linking of projections to possible policy instruments for influencing them.

  14. Aircraft type influence on contrail properties

    Directory of Open Access Journals (Sweden)

    P. Jeßberger

    2013-05-01

    Full Text Available The investigation of the impact of aircraft parameters on contrail properties helps to better understand the climate impact from aviation. Yet, in observations, it is a challenge to separate aircraft and meteorological influences on contrail formation. During the CONCERT campaign in November 2008, contrails from 3 Airbus passenger aircraft of type A319-111, A340-311 and A380-841 were probed at cruise under similar meteorological conditions with in-situ instruments on board the DLR research aircraft Falcon. Within the 2 min old contrails detected near ice saturation, we find similar effective diameters Deff (5.2–5.9 μm, but differences in particle number densities nice (162–235 cm−3 and in vertical contrail extensions (120–290 m, resulting in large differences in contrail optical depths τ (0.25–0.94. Hence larger aircraft produce optically thicker contrails. Based on the observations, we apply the EULAG-LCM model with explicit ice microphysics and in addition the Contrail and Cirrus Prediction model CoCiP to calculate the aircraft type impact on young contrails under identical meteorological conditions. The observed increase in τ for heavier aircraft is confirmed by the models, yet for generally smaller τ. An aircraft dependence of climate relevant contrail properties persists during contrail lifetime, adding importance to aircraft dependent model initialization. We finally derive an analytical relationship between contrail, aircraft and meteorological parameters. Near ice saturation, contrail width × τ scales linearly with fuel flow rate as confirmed by observations. For higher saturation ratios approximations from theory suggest a non-linear increase in the form (RHI–12/3. Summarized our combined results could help to more accurately assess the climate impact from aviation using an aircraft dependent contrail parameterization.

  15. Aircraft and Pavement Deicer and Anti-Icer Forensics: Which Formulations Reach the Receiving Water and What are Their Potential Impacts

    Science.gov (United States)

    To characterize the effects from runoff of aircraft deicer and anti-icer fluid (ADAF) and pavement deicer formulations (PDF) on receiving water, multiple deicing and anti-icing formulations must be considered. ADAF formulations used on aircraft include Type I fluids (deicers) and Type IV fluids (an...

  16. The resistance to impact of spent Magnox fuel transport flasks

    International Nuclear Information System (INIS)

    This book completes the papers of the four-year programme of research and demonstrations embarked upon by the CEGB in 1981, culminating in the spectacular train crash at Old Dalby in July 1984. It explains the CEGB's operations in relation to the transportation of spent Magnox fuel. The public tests described in this book are more effective in improving public understanding and confidence than any amount of explanations could have been, raising the wider question of how best the scientific community can respond to the legitimate concerns of the man and woman in the street about the generating of electricity from nuclear power. The contents are: Taking care; irradiated fuel transport in the UK; programming for flask safety; the use of scale models in impact testing; flask analytical studies; drop test facilities; demonstration drop test; a study of flask transport impact hazards; impact of Magnox irradiated fuel transport flasks into rock and concrete; rail crash demonstration scenarios; horizontal impact testing of quarter scale flasks using masonry targets; horizontal crash testing and analysis of model flatrols; flatrol test; analysis of full scale impact into an abutment; analysis of primary impact forces in the train crash demonstration; horizontal impact tests of quarter scale Magnox flasks and stylised model locomotives; predictive estimates for behaviour in the train crash demonstration; design and organization of the crash; execution of the crash demonstration by British Rail; instrumentation for the train crash demonstration; photography for the crash demonstration; a summary of the CEGB's flask accident impact studies

  17. Research on Emerging and Descending Aircraft Noise

    Directory of Open Access Journals (Sweden)

    Monika Bartkevičiūtė

    2013-12-01

    Full Text Available Along with an increase in the aircraft engine power and growth in air traffic, noise level at airports and their surrounding environs significantly increases. Aircraft noise is high level noise spreading within large radius and intensively irritating the human body. Air transport is one of the main sources of noise having a particularly strong negative impact on the environment. The article deals with activities and noises taking place in the largest nationwide Vilnius International Airport.The level of noise and its dispersion was evaluated conducting research on the noise generated by emerging and descending aircrafts in National Vilnius Airport. Investigation was carried out at 2 measuring points located in a residential area. There are different types of aircrafts causing different sound levels. It has been estimated the largest exceedances that occur when an aircraft is approaching. In this case, the noisiest types of aircrafts are B733, B738 and AT72. The sound level varies from 70 to 85 dBA. The quietest aircrafts are RJ1H and F70. When taking off, the equivalent of the maximum sound level value of these aircrafts does not exceed the authorized limits. The paper describes the causes of noise in aircrafts, the sources of origin and the impact of noise on humans and the environment.Article in Lithuanian

  18. Using unmanned aircraft to measure the impact of pollution plumes on atmospheric heating rates and cloud properties during the Cheju ABC Plume-Asian Monsoon Experiment (CAPMEX)

    Science.gov (United States)

    Venkata Ramana, M.; Ramanathan, V.; Nguyen, H.; Xu, Y.; Pistone, K.; Corrigan, C.; Feng, Y.; Zhu, A.; Kim, S.; Yoon, S.; Carmichael, G. R.; Schauer, J. J.

    2009-12-01

    The CAPMEX (Cheju ABC Plume-Asian Monsoon Experiment) campaign took place off the Coast of Cheju Island in South Korea to take advantage of the unique event associated with the shutdown of anthropogenic emissions surrounding Beijing during the Olympics in summer 2008. CAPMEX studied pollution plumes before, during, and after the Beijing reductions using ground-level and high-elevation measurements, i.e., from unmanned aircrafts. Additionally, the campaign documented the effect on solar heating and clouds due to aerosols carried by the long range transport of pollution plumes. The unmanned aerial vehicle (UAV) measurement component of this campaign took place during Aug 9 to Sept 30, 2008. The AUAV payload was mission-specific and was outfitted to perform a particular set of measurements. These measurements include aerosol concentration, aerosol size distribution, aerosol absorption, cloud drop size distribution, solar radiation fluxes (visible and broadband), and spectral radiative fluxes. Throughout the CAPMEX experiment, long-range transport of aerosols from Beijing, Shanghai and Marine plumes were sampled in aerosol layers up to 3-4 km above sea level. During this period, we captured both heavy and light pollution events and witnessed air masses from both pristine oceanic sources and from major cities including Beijing and Shanghai. Analysis of specific plumes allowed us to quantify the impact of anthropogenic pollution on heating rates and cloud properties.

  19. Fatigue-related crashes involving express buses in Malaysia: will the proposed policy of banning the early-hour operation reduce fatigue-related crashes and benefit overall road safety?

    Science.gov (United States)

    Mohamed, Norlen; Mohd-Yusoff, Mohammad-Fadhli; Othman, Ilhamah; Zulkipli, Zarir-Hafiz; Osman, Mohd Rasid; Voon, Wong Shaw

    2012-03-01

    Fatigue-related crashes have long been the topic of discussion and study worldwide. The relationship between fatigue-related crashes and time of day is well documented. In Malaysia, the possibility of banning express buses from operating during the early-hours of the morning has emerged as an important consideration for passenger safety. This paper highlights the findings of an impact assessment study. The study was conducted to determine all possible impacts prior to the government making any decision on the proposed banning. This study is an example of a simple and inexpensive approach that may influence future policy-making process. The impact assessment comprised two major steps. The first step involved profiling existing operation scenarios, gathering information on crashes involving public express buses and stakeholders' views. The second step involved a qualitative impact assessment analysis using all information gathered during the profiling stage to describe the possible impacts. Based on the assessment, the move to ban early-hour operations could possibly result in further negative impacts on the overall road safety agenda. These negative impacts may occur if the fundamental issues, such as driving and working hours, and the need for rest and sleep facilities for drivers, are not addressed. In addition, a safer and more accessible public transportation system as an alternative for those who choose to travel at night would be required. The proposed banning of early-hour operations is also not a feasible solution for sustainability of express bus operations in Malaysia, especially for those operating long journeys. The paper concludes by highlighting the need to design a more holistic approach for preventing fatigue-related crashes involving express buses in Malaysia. PMID:22239931

  20. Numerical Reconstruction and Injury Biomechanism in a Car-Pedestrian Crash Accident

    Institute of Scientific and Technical Information of China (English)

    ZOU Dong-hua; LI Zheng-dong; SHAO Yu; FENG Hao; CHEN Jian-guo; LIU Ning-guo; HUANG Ping; CHEN Yi-jiu

    2012-01-01

    Objective To reconstruct a car-pedestrian crash accident using numerical simulation technology and explore the injury biomechanism as forensic evidence for injury identification.Methods An integration of multi-body dynamic,finite elcment (FE),and classical method was applied to a car-pedestrian crash accident.The location of the collision and the details of the traffic accident were determined by vehicle trace verification and autopsy.The accident reconstruction was performed by coupling the three-dimensional car behavior from PC-CRASH with a MADYMO dummy model.The collision FE models of head and leg,developed from CT scans of human remains,were loaded with calculated dummy collision parameters.The data of the impact biomechanical responses were extracted in terms of von Mises stress,relative displacement,strain and stress fringes.Results The accident reconstruction results were identical with the examined ones and the biomechanism of head and leg injuries,illustrated through the FE methods,were consistent with the classical injury theories.Conclusion The numerical simulation technology is proved to be effective in identifying traffic accidents and exploring of injury biomechanism.

  1. Assessment of aircraft risk reduction at Pantex Plant

    International Nuclear Information System (INIS)

    The possibility of an aircraft crashing into the Department of Energy's (DOE) Pantex plant facility has been of concern in risk assessments. In response to public concerns, and in an effort to reduce risks associated with overflights of Pantex, several changes to navigational aids at Amarillo International Airport have been implemented. For over one year, a radar airspace monitor and recording system has been connected to the airport surveillance radar at Amarillo to record the flight paths, aircraft types, and traffic density of aircraft in the vicinity of the Pantex plant. The data has provided a better understanding of the overflight risk at Pantex as well as a means to measure the effectiveness of risk reduction efforts

  2. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A.G.; Stordal, F.; Knudsen, S. [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  3. Injury Risk for Rear-Seated Occupants in Small Overlap Crashes

    OpenAIRE

    Arbogast, Kristy B.; Locey, Caitlin M.; Hammond, Rachel; Belwadi, Aditya

    2013-01-01

    Small overlap crashes, where the primary crash engagement is outboard from the longitudinal energy absorbing structures of the vehicle, have received recent interest as a crash dynamic that results in high likelihood of injury. Previous analyses of good performing vehicles showed that 24% of crashes with AIS 3+ injuries to front seat occupants were small overlap crashes. However, similar evaluations have not been conducted for those rear seated. Vehicle dynamics suggest that rear seat occupan...

  4. Linux Crash Dump的设计与实现%AN INTRODUCTION TO DESIGN AND IMPLEMENTATION OF Linux Crash Dump

    Institute of Scientific and Technical Information of China (English)

    王勇; 沈亚谦; 潘金贵

    2002-01-01

    本文介绍了Linux Crash Dump的设计与实现方法.Linux Crash Dump提供了一种保存系统在发生Crash时内存映象的能力.通过对Dump结果的分析,可以有效地帮助诊断系统出错的原因.本文介绍了如何进行Crash Dump,以及Dump的数据的组织和保存方法等.

  5. A multinomial-logit ordered-probit model for jointly analyzing crash avoidance maneuvers and crash severity

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Prato, Carlo Giacomo

    the United States National Automotive Sampling System General Estimates System (GES) crash database for the years 2005-2009. Results show (i) the correlation between crash avoidance maneuvers and crash severity, and (ii) the link between drivers' attributes, risky driving behavior, road......' propensity to engage in various corrective maneuvers in the case of the critical event of vehicle travelling. Five lateral and speed control maneuvers are considered: “braking”, “steering”, “braking & steering”, and “other maneuvers”, in addition to a “no action” option. The analyzed data are retrieved from...

  6. Frequency Analysis of Aircraft hazards for License Application

    International Nuclear Information System (INIS)

    The preclosure safety analysis for the monitored geologic repository at Yucca Mountain must consider the hazard that aircraft may pose to surface structures. Relevant surface structures are located beneath the restricted airspace of the Nevada Test Site (NTS) on the eastern slope of Yucca Mountain, near the North Portal of the Exploratory Studies Facility Tunnel (Figure 1). The North Portal is located several miles from the Nevada Test and Training Range (NTTR), which is used extensively by the U.S. Air Force (USAF) for training and test flights (Figure 1). The NTS airspace, which is controlled by the U.S. Department of Energy (DOE) for NTS activities, is not part of the NTTR. Agreements with the DOE allow USAF aircraft specific use of the airspace above the NTS (Reference 2.1.1 [DIRS 103472], Section 3.1.1 and Appendix A, Section 2.1; and Reference 2.1.2 [DIRS 157987], Sections 1.26 through 1.29). Commercial, military, and general aviation aircraft fly within several miles to the southwest of the repository site in the Beatty Corridor, which is a broad air corridor that runs approximately parallel to U.S. Highway 95 and the Nevada-California border (Figure 2). These aircraft and other aircraft operations are identified and described in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Sections 6 and 8). The purpose of this analysis is to estimate crash frequencies for aircraft hazards identified for detailed analysis in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Section 8). Reference 2.1.3, Section 8, also identifies a potential hazard associated with electronic jamming, which will be addressed in this analysis. This analysis will address only the repository and not the transportation routes to the site. The analysis is intended to provide the basis for: (1) Categorizing event sequences related to aircraft hazards; (2) Identifying design or operational requirements related to aircraft hazards

  7. Heavy Vehicle Crash Characteristics in Oman; 2009–2011

    Directory of Open Access Journals (Sweden)

    Islam Al-Bulushi

    2015-05-01

    Full Text Available In recent years, Oman has seen a shift in the burden of diseases towards road accidents. The main objective of this paper, therefore, is to describe key characteristics of heavy vehicle crashes in Oman and identify the key driving behaviours that influence fatality risks. Crash data from January 2009 to December 2011 were examined and it was found that, of the 22,543 traffic accidents that occurred within this timeframe, 3,114 involved heavy vehicles. While the majority of these crashes were attributed to driver behaviours, a small proportion was attributed to other factors. The results of the study indicate that there is a need for a more thorough crash investigation process in Oman. Future research should explore the reporting processes used by the Royal Oman Police, cultural influences on heavy vehicle operations in Oman and improvements to the current licensing system.

  8. Determinants of road traffic crash fatalities across Indian States

    NARCIS (Netherlands)

    M. Grimm (Michael); C. Treibich (Carole)

    2012-01-01

    textabstractObjective: This paper explores the determinants of road traffic crash fatalities in India. As potential factors, the analysis considers, besides income, the sociodemographic populationstructure, motorization levels, road and health infrastructure and road rule enforcement. Methods: An or

  9. Relationship between organisational safety culture dimensions and crashes.

    Science.gov (United States)

    Varmazyar, Sakineh; Mortazavi, Seyed Bagher; Arghami, Shirazeh; Hajizadeh, Ebrahim

    2016-01-01

    Knowing about organisational safety culture in public transportation system can provide an appropriate guide to establish effective safety measures and interventions to improve safety at work. The aim of this study was investigation of association between safety culture dimensions (leadership styles and company values, usage of crashes information and prevention programmes, management commitment and safety policy, participation and control) with involved self-reported crashes. The associations were considered through Spearman correlation, Pearson chi-square test and logistic regression. The results showed an association among self-reported crashes (occurrence or non-occurrence) and factors including leadership styles and company values; management commitment and safety policy; and control. Moreover, it was found a negative correlation and an odds ratio less than one between control and self-reported crashes. PMID:25494102

  10. Screening of external hazards for NPP with bank type reactor. Modeling of safety related systems and equipment for RBMK. Probabilistic assessment of NPP safety on aircraft impact. Progress report

    International Nuclear Information System (INIS)

    This progress report was produced within the frame of IAEA research project on screening the hazards for NPP with bank type reactor. It covers the following tasks; development of the model for the primary loop system of RBMK; developing the models for safety related equipment of RBMK; developing of models for safety related models of EGP-6 type reactor (Bilibinskaya Nuclear Co-generated heat and Power Plant); and probabilistic assessment of NPP safety on aircraft impact

  11. A fuzzy logic approach to modeling a vehicle crash test

    OpenAIRE

    Pawlus, Witold; Karimi, Hamid Reza; Robbersmyr, Kjell G.

    2012-01-01

    This paper presents an application of fuzzy approach to vehicle crash modeling. A typical vehicle to pole collision is described and kinematics of a car involved in this type of crash event is thoroughly characterized. The basics of fuzzy set theory and modeling principles based on fuzzy logic approach are presented. In particular, exceptional attention is paid to explain the methodology of creation of a fuzzy model of a vehicle collision. Furthermore, the simulation results are presented and...

  12. Dynamics of a financial market index after a crash

    OpenAIRE

    Fabrizio Lillo; Mantegna, Rosario N.

    2002-01-01

    We discuss the statistical properties of index returns in a financial market just after a major market crash. The observed non-stationary behavior of index returns is characterized in terms of the exceedances over a given threshold. This characterization is analogous to the Omori law originally observed in geophysics. By performing numerical simulations and theoretical modelling, we show that the nonlinear behavior observed in real market crashes cannot be described by a GARCH(1,1) model. We ...

  13. Trade Deficit News, Systematic Risk and the Crash of 1987

    OpenAIRE

    Willem Thorbecke

    1994-01-01

    News of enormous trade deficits began affecting asset prices in the mid-1980s. Some have suggested that trade deficit news contributed to the October 1987 stock market crash. This argument would be more compelling if the trade deficit were a source of systematic risk to asset prices, since then trade deficit news could have contributed to the increased perception of the riskiness of holding equities that occurred just before the crash. Here the Arbitrage Pricing Theory is used to demonstrate ...

  14. Forensic odontological observations in the victims of DANA air crash

    OpenAIRE

    Obafunwa, John Oladapo; Ogunbanjo, Victor Olabode; Ogunbanjo, Ogunbiyi Babatunde; Soyemi, Sunday Sokunle; Faduyile, Francis Adedayo

    2015-01-01

    Introduction Forensic odontology or forensic dentistry is that aspect of forensic science that uses the application of dental science for the identification of unknown human remains and bite marks. Deaths resulting from mass disasters such as plane crash or fire incidence have always been given mass burial in Nigeria. This was obviously due to the fact that Forensic Pathologists whose roles involve disaster victim identification were not available at that time. However, in the DANA air crash ...

  15. Large plastic deformations of a spherical shell under impact

    International Nuclear Information System (INIS)

    An approximate solution to the problem of a spherical cap impacted by a rigid mass is derived. The dimensions of the mass are assumed finite but small as compared to the characteristic dimension of the shell. Following a static solution of a similar problem by Updike a simple mechanism of deformation is assumed in which plastic deformations are spreading out from the center towards the periphery of the shell. This mechanism permits to consider the shell as a one-degree-of-freedom dynamical system. In the method used no restrictions are set on the value of permanent deflections attained. As a result of numerical computations plots of the central deflections versus time and maximum central deflections as a function of the kinetic energy input were obtained. The presented solution might be of some value in the design of nuclear power plant containment structures for aircraft crash impact forces. (orig./HP)

  16. Corrosion Sensor Development for Condition-Based Maintenance of Aircraft

    OpenAIRE

    Gino Rinaldi; Trisha Huber; Heather McIntosh; Les Lebrun; Heping Ding; John Weber

    2012-01-01

    Aircraft routinely operate in atmospheric environments that, over time, will impact their structural integrity. Material protection and selection schemes notwithstanding, recurrent exposure to chlorides, pollution, temperature gradients, and moisture provide the necessary electrochemical conditions for the development and profusion of corrosion in aircraft structures. For aircraft operators, this becomes an important safety matter as corrosion found in a given aircraft must be assumed to be p...

  17. Turboelectric Aircraft Drive Key Performance Parameters and Functional Requirements

    Science.gov (United States)

    Jansen, Ralph H.; Brown, Gerald V.; Felder, James L.; Duffy, Kirsten P.

    2016-01-01

    The purpose of this paper is to propose specific power and efficiency as the key performance parameters for a turboelectric aircraft power system and investigate their impact on the overall aircraft. Key functional requirements are identified that impact the power system design. Breguet range equations for a base aircraft and a turboelectric aircraft are found. The benefits and costs that may result from the turboelectric system are enumerated. A break-even analysis is conducted to find the minimum allowable electric drive specific power and efficiency that can preserve the range, initial weight, operating empty weight, and payload weight of the base aircraft.

  18. Finite element analysis of the impact response of reinforced concrete structures using DYNA3D

    International Nuclear Information System (INIS)

    Reinforced concrete structures in nuclear installations are potentially subject to accidental impact from external or internally generated hazards. These include: soft impacts such as aircraft crash on containment structures; and hard impacts such as heavy dropped loads on pond floors, or plant-generated fragments on structural and protective walls. The explicit finite element code DYNA3D has been used extensively for analysis of the response of structures to dynamic loadings, and a constitutive material model for reinforced concrete has been developed within DYNA3D to represent local cracking and crushing due to impact loads, as well as treating the elastic and plastic global response modes of the structure. This model has been extensively validated against impact tests for simulated aircraft impact on containment structures, but more recent interest has concentrated on analysis of hard impacts on floors and walls. Whilst a simplified constitutive model is adequate for the response to soft impacts, in which the dominant response mode is flexural, the local damage and high rates experienced in hard impacts have required further development of the material model. This paper describes the main features of the constitutive model, and presents the results of a validation case of a heavy dropped load on a reinforced concrete floor. (author)

  19. Definition of 1992 Technology Aircraft Noise Levels and the Methodology for Assessing Airplane Noise Impact of Component Noise Reduction Concepts

    Science.gov (United States)

    Kumasaka, Henry A.; Martinez, Michael M.; Weir, Donald S.

    1996-01-01

    This report describes the methodology for assessing the impact of component noise reduction on total airplane system noise. The methodology is intended to be applied to the results of individual study elements of the NASA-Advanced Subsonic Technology (AST) Noise Reduction Program, which will address the development of noise reduction concepts for specific components. Program progress will be assessed in terms of noise reduction achieved, relative to baseline levels representative of 1992 technology airplane/engine design and performance. In this report, the 1992 technology reference levels are defined for assessment models based on four airplane sizes - an average business jet and three commercial transports: a small twin, a medium sized twin, and a large quad. Study results indicate that component changes defined as program final goals for nacelle treatment and engine/airframe source noise reduction would achieve from 6-7 EPNdB reduction of total airplane noise at FAR 36 Stage 3 noise certification conditions for all of the airplane noise assessment models.

  20. Linux Crash Dump分析工具的设计与实现%The Design and Implementation of an Analysis Tool of Linux Crash Dump

    Institute of Scientific and Technical Information of China (English)

    沈亚谦; 王勇; 潘金贵

    2002-01-01

    提出了一种利用Linux Crash Dump以及对Dump的分析来进行Linux系统调试的方法.着重描述了在目前Linux系统中添加Crash Dump功能的方法和Linux Crash Dump分析工具的具体实现方案.

  1. Investigating the Effects of Side Airbag Deployment in Real-World Crashes Using Crash Comparison Techniques

    OpenAIRE

    Loftis, Kathryn L.; Weaver, Ashley A.; Stitzel, Joel D.

    2011-01-01

    The objective of this study was to investigate side airbag (SAB) deployment in near side crashes and compare injuries and contact points between occupants with and without SAB deployment. Using NASS 2000–2008 and selecting for near side cases, with PDOF ± 20 degrees from 90 or 270, for non-pregnant adult belted occupants, there were 20,253 (weighted) SAB deployments. NASS showed that SABs have been increasing within the fleet, comprising 2% of airbags in 2000 and increasing to 33% of airbags ...

  2. Role of Motorcycle Running Lights in Reducing Motorcycle Crashes during Daytime; A Review of the Current Literature.

    Science.gov (United States)

    Davoodi, Seyed Rasoul; Hossayni, Seyed Mohamad

    2015-07-01

    In comparison to other transportation modes, riding motorcycle is prone to accidents. Motorcyclists are more exposed to physical injury than the car drivers. Many multi-vehicle motorcycles crashes occur, there is right-of- way violation takes place in which another vehicle turns in fronts of a motorcycle, or a sudden cross of path of an on-coming motorcycle. One main factor which leads to high rate of motorcycle crashes is lack of conspicuity of motorcycles by other road users especially during day time traffic. This paper highlights previous studies on the implementation of motorcycle DRLs, focusing on the efficacy of the DRLs to improve motorcycle conspicuity. This paper reviews the impacts of DRL by motorcyclists on multi-vehicle motorcycle crash. The three categories of effects of motorcycle DRLs were reviewed. All literature, supporting that operating headlights during daytime appears to be an influential and effective approach to reduce rate of collision by improving motorcycle's conspicuity in traffic. The motorcycle DRLs managed to reduce about 4 to 20% of motorcycle crash risk. This paper also recommends that motorcycle DRLs must be used globally, especially in countries with high motorcycle accidents to improve the safety of the riders as well as their pillion riders. PMID:27162907

  3. Role of Motorcycle Running Lights in Reducing Motorcycle Crashes during Daytime; A Review of the Current Literature

    Directory of Open Access Journals (Sweden)

    Seyed Rasoul Davoodi

    2015-07-01

    Full Text Available In comparison to other transportation modes, riding motorcycle is prone to accidents. Motorcyclists are more exposed to physical injury than the car drivers. Many multi-vehicle motorcycles crashes occur, there is right-of- way violation takes place in which another vehicle turns in fronts of a motorcycle, or a sudden cross of path of an on-coming motorcycle. One main factor which leads to high rate of motorcycle crashes is lack of conspicuity of motorcycles by other road users especially during day time traffic. This paper highlights previous studies on the implementation of motorcycle DRLs, focusing on the efficacy of the DRLs to improve motorcycle conspicuity. This paper reviews the impacts of DRL by motorcyclists on multi-vehicle motorcycle crash. The three categories of effects of motorcycle DRLs were reviewed. All literature, supporting that operating headlights during daytime appears to be an influential and effective approach to reduce rate of collision by improving motorcycle’s conspicuity in traffic. The motorcycle DRLs managed to reduce about 4 to 20% of motorcycle crash risk. This paper also recommends that motorcycle DRLs must be used globally, especially in countries with high motorcycle accidents to improve the safety of the riders as well as their pillion riders.

  4. The Development of Two Composite Energy Absorbers for Use in a Transport Rotorcraft Airframe Crash Testbed (TRACT 2) Full-Scale Crash Test

    Science.gov (United States)

    Littell, Justin D.; Jackson, Karen E.; Annett, Martin S.; Seal, Michael D.; Fasanella, Edwin L.

    2015-01-01

    Two composite energy absorbers were developed and evaluated at NASA Langley Research Center through multi-level testing and simulation performed under the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program. A conical-shaped energy absorber, designated the conusoid, was evaluated that consisted of four layers of hybrid carbon-Kevlar plain weave fabric oriented at [+45deg/-45deg/-45deg/+45deg] with respect to the vertical direction. A sinusoidal-shaped energy absorber, designated the sinusoid, was developed that consisted of hybrid carbon-Kevlar plain weave fabric face sheets, two layers for each face sheet oriented at +/-45deg with respect to the vertical direction, and a closed-cell ELFOAM P200 polyisocyanurate (2.0-lb/cu ft) foam core. The design goal for the energy absorbers was to achieve average floor-level accelerations of between 25- and 40-g during the full-scale crash test of a retrofitted CH-46E helicopter airframe, designated TRACT 2. Variations in both designs were assessed through dynamic crush testing of component specimens. Once the designs were finalized, subfloor beams of each configuration were fabricated and retrofitted into a barrel section of a CH-46E helicopter. A vertical drop test of the barrel section was conducted onto concrete to evaluate the performance of the energy absorbers prior to retrofit into TRACT 2. The retrofitted airframe was crash tested under combined forward and vertical velocity conditions onto soft soil. Finite element models were developed of all test articles and simulations were performed using LS-DYNA, a commercial nonlinear explicit transient dynamic finite element code. Test-analysis results are presented for each energy absorber as comparisons of time-history responses, as well as predicted and experimental structural deformations and progressive damage under impact loading for each evaluation level.

  5. Effects of Dram Shop, Responsible Beverage Service Training, and State Alcohol Control Laws on Underage Drinking Driver Fatal Crash Ratios

    Science.gov (United States)

    Scherer, Michael; Fell, James C.; Thomas, Sue; Voas, Robert B.

    2015-01-01

    Objectives In this study, we aimed to determine whether three minimum legal drinking age 21 (MLDA-21) laws—dram shop liability, responsible beverage service (RBS) training, and state control of alcohol sales—have had an impact on underage drinking-and-driving fatal crashes using annual state-level data, and compared states with strong laws to those with weak laws to examine their effect on beer consumption and fatal crash ratios. Methods Using the Fatality Analysis Reporting System, we calculated the ratio of drinking to nondrinking drivers under age 21 involved in fatal crashes as our key outcome measure. We used structural equation modeling to evaluate the three MLDA-21 laws. We controlled for covariates known to impact fatal crashes including: 17 additional MLDA-21 laws; administrative license revocation; blood alcohol concentration limits of .08 and .10 for driving; seat belt laws; sobriety checkpoint frequency; unemployment rates; and vehicle miles traveled. Outcome variables, in addition to the fatal crash ratios of drinking to nondrinking drivers under age 21 included state per capita beer consumption. Results Dram shop liability laws were associated with a 2.4% total effect decrease (direct effects: β = .019, p = .018). Similarly, RBS training laws were associated with a 3.6% total effect decrease (direct effects: β = .048, p = .001) in the ratio of drinking to nondrinking drivers under age 21 involved in fatal crashes. There was a significant relationship between dram shop liability law strength and per capita beer consumption, F (4, 1528) = 24.32, p < .001, partial η2 = .016, showing states with strong dram shop liability laws (Mean (M) = 1.276) averaging significantly lower per capita beer consumption than states with weak laws (M = 1.340). Conclusions Dram shop liability laws and RBS laws were both associated with significantly reduced per capita beer consumption and fatal crash ratios. In practical terms, this means that dram shop liability laws

  6. Modeling Composite Laminate Crushing for Crash Analysis

    Science.gov (United States)

    Fleming, David C.; Jones, Lisa (Technical Monitor)

    2002-01-01

    Crash modeling of composite structures remains limited in application and has not been effectively demonstrated as a predictive tool. While the global response of composite structures may be well modeled, when composite structures act as energy-absorbing members through direct laminate crushing the modeling accuracy is greatly reduced. The most efficient composite energy absorbing structures, in terms of energy absorbed per unit mass, are those that absorb energy through a complex progressive crushing response in which fiber and matrix fractures on a small scale dominate the behavior. Such failure modes simultaneously include delamination of plies, failure of the matrix to produce fiber bundles, and subsequent failure of fiber bundles either in bending or in shear. In addition, the response may include the significant action of friction, both internally (between delaminated plies or fiber bundles) or externally (between the laminate and the crushing surface). A figure shows the crushing damage observed in a fiberglass composite tube specimen, illustrating the complexity of the response. To achieve a finite element model of such complex behavior is an extremely challenging problem. A practical crushing model based on detailed modeling of the physical mechanisms of crushing behavior is not expected in the foreseeable future. The present research describes attempts to model composite crushing behavior using a novel hybrid modeling procedure. Experimental testing is done is support of the modeling efforts, and a test specimen is developed to provide data for validating laminate crushing models.

  7. Crash testing of nuclear fuel shipping containers

    International Nuclear Information System (INIS)

    In an attempt to understand the dynamics of extra severe transportation accidents and to evaluate state-of-the-art computational techniques for predicting the dynamic response of shipping casks involved in vehicular system crashes, the Environmental Control Technology Division of ERDA undertook a program with Sandia to investigate these areas. The program encompasses the following distinct major efforts. The first of these utilizes computational methods for predicting the effects of the accident environment and, subsequently, to calculate the damage incurred by a container as the result of such an accident. The second phase involves the testing of 1/8-scale models of transportation systems. Through the use of instrumentation and high-speed motion photography the accident environments and physical damage mechanisms are studied in detail. After correlating the results of these first two phases, a full scale event involving representative hardware is conducted. To date two of the three selected test scenarios have been completed. Results of the program to this point indicate that both computational techniques and scale modeling are viable engineering approaches to studying accident environments and physical damage to shipping casks

  8. Safety analysis of casks under extreme impact conditions

    International Nuclear Information System (INIS)

    The determination of the inherent safety of casks also under extreme impact conditions has been of increasing interest since the terrorist attacks from 11th September 2001. For nearly three decades BAM has been investigating cask safety under severe accident conditions like drop tests from more than 9 m onto different targets and without impact limiters as well as artificially damaged prototype casks. One of the most critical scenarios for a cask is the centric impact of a dynamic load onto the lid seal system. This can be caused e.g. by direct aircraft crash or its engine as well as by an impact due to the collapse of a building e.g. a nuclear facility storage hall. In this context BAM is developing methods to calculate the deformation of cask components and - with respect to leak tightness - relative displacements between the metallic seals and their counterparts. This paper presents reflections on modelling of cask structures for Finite Element analyses and discusses calculated results of stresses and deformations. Another important aspect is the behaviour of a cask under a lateral impact by aircraft and fragments of a building. Examples of the kinetic reaction (cask acceleration due to the fragments, subsequent contact with neighbouring structures like ground, buildings or casks) are shown and discussed in correlation to cask stresses which are to be expected

  9. Vehicular Causation Factors and Conceptual Design Modifications to Reduce Aortic Strain in Numerically Reconstructed Real World Nearside Lateral Automotive Crashes

    Directory of Open Access Journals (Sweden)

    Aditya Belwadi

    2015-01-01

    Full Text Available Aortic injury (AI leading to disruption of the aorta is an uncommon but highly lethal consequence of trauma in modern society. Most recent estimates range from 7,500 to 8,000 cases per year from a variety of causes. It is observed that more than 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest cavity. It is evident that effective means of substantially improving the outcome of motor vehicle crash-induced AIs is by preventing the injury in the first place. In the current study, 16 design of computer experiments (DOCE were carried out with varying levels of principal direction of force (PDOF, impact velocity, impact height, and impact position of the bullet vehicle combined with occupant seating positions in the case vehicle to determine the effects of these factors on aortic injury. Further, a combination of real world crash data reported in the Crash Injury Research and Engineering Network (CIREN database, Finite Element (FE vehicle models, and the Wayne State Human Body Model-II (WSHBM-II indicates that occupant seating position, impact height, and PDOF, in that order play, a primary role in aortic injury.

  10. Finite element crash simulations of the human body: Passive and active muscle modelling

    Indian Academy of Sciences (India)

    S Mukherjee; A Chawla; B Karthikeyan; A Soni

    2007-08-01

    Conventional dummy based testing procedures suffer from known limitations. This report addresses issues in finite element human body models in evaluating pedestrian and occupant crash safety measures. A review of material properties of soft tissues and characterization methods show a scarcity of material properties for characterizing soft tissues in dynamic loading. Experiments imparting impacts to tissues and subsequent inverse finite element mapping to extract material properties are described. The effect of muscle activation due to voluntary and non-voluntary reflexes on injuries has been investigated through finite element modelling.

  11. Analysis of road traffic crash injuries - a technique producing large un-decalcified histological sections

    DEFF Research Database (Denmark)

    Uhrenholt, Lars; Gregersen, Markil Ebbe Gregers; Vesterby, Annie;

    Introduction:The lower cervical spine facet joints are important structures in cases of chronic pain syndromes following road traffic crashes. Pathophysiological segmental kinematics may occur, particularly during rear-impact collisions, which may cause injury to these joints. Detailed anatomical...... that prepares large un-frozen un-decalcified cervical spine specimens for analysis. Materials and Methods:The cervical spine segments from C4 to C7 are removed en bloc during autopsy. The specimen is fixed throughout in 70% increasing to 99% ethanol and embedded un-decalcified in hardening methyl methacrylate...

  12. Modelling the hierarchical structure of road crash data : application to severity analysis

    OpenAIRE

    Lenguerrand, E.; MARTIN,JL; Laumon, B.

    2006-01-01

    Road crashes have an unquestionably hierarchical crash-car-occupant structure. Multilevel models are used with correlated data, but their application to crash data can be difficult. The number of sub-clusters per cluster is small, with less than two cars per crash and less than two occupants per car, whereas the number of clusters can be high, with several hundred/thousand crashes. Application of the Monte-Carlo method on observed and simulated French road crash data between 1996 and 2000 all...

  13. The contribution of aircraft emissions to the atmospheric sulfur budget

    Energy Technology Data Exchange (ETDEWEB)

    Kjellstroem, E. [Stockholm Univ. (Sweden). Dept. of Meteorology; Feichter, J. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Sausen, R.; Hein, R. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1998-01-01

    An atmospheric general circulation model including the atmospheric sulfur cycle has been used to investigate the impact of aircraft sulfur emissions on the global sulfur budget of the atmosphere. The relative contribution from aircraft sulfur to the atmospheric sulfate burden is larger than the ratio between aircraft emissions and surface emissions due to the calculated long turn-over time of aircraft sulfate (about 12 days). However, in terms of the sulfate mass balance, aircraft emissions are small, contributing about 1% of the total sulfate mass north of 40 deg C where the aircraft emissions are largest. Despite this small contribution to sulfate mass, the aircraft emissions could potentially significantly enhance the background number concentration of aerosol particles. Based on the model calculations the increased stratospheric background aerosol mass observed during the last decades can not be explained by increased aircraft sulfur emissions 50 refs, 9 figs, 4 tabs

  14. Propulsion controlled aircraft computer

    Science.gov (United States)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  15. Support vector machine in crash prediction at the level of traffic analysis zones: Assessing the spatial proximity effects.

    Science.gov (United States)

    Dong, Ni; Huang, Helai; Zheng, Liang

    2015-09-01

    In zone-level crash prediction, accounting for spatial dependence has become an extensively studied topic. This study proposes Support Vector Machine (SVM) model to address complex, large and multi-dimensional spatial data in crash prediction. Correlation-based Feature Selector (CFS) was applied to evaluate candidate factors possibly related to zonal crash frequency in handling high-dimension spatial data. To demonstrate the proposed approaches and to compare them with the Bayesian spatial model with conditional autoregressive prior (i.e., CAR), a dataset in Hillsborough county of Florida was employed. The results showed that SVM models accounting for spatial proximity outperform the non-spatial model in terms of model fitting and predictive performance, which indicates the reasonableness of considering cross-zonal spatial correlations. The best model predictive capability, relatively, is associated with the model considering proximity of the centroid distance by choosing the RBF kernel and setting the 10% of the whole dataset as the testing data, which further exhibits SVM models' capacity for addressing comparatively complex spatial data in regional crash prediction modeling. Moreover, SVM models exhibit the better goodness-of-fit compared with CAR models when utilizing the whole dataset as the samples. A sensitivity analysis of the centroid-distance-based spatial SVM models was conducted to capture the impacts of explanatory variables on the mean predicted probabilities for crash occurrence. While the results conform to the coefficient estimation in the CAR models, which supports the employment of the SVM model as an alternative in regional safety modeling. PMID:26091769

  16. A Poisson-lognormal conditional-autoregressive model for multivariate spatial analysis of pedestrian crash counts across neighborhoods.

    Science.gov (United States)

    Wang, Yiyi; Kockelman, Kara M

    2013-11-01

    This work examines the relationship between 3-year pedestrian crash counts across Census tracts in Austin, Texas, and various land use, network, and demographic attributes, such as land use balance, residents' access to commercial land uses, sidewalk density, lane-mile densities (by roadway class), and population and employment densities (by type). The model specification allows for region-specific heterogeneity, correlation across response types, and spatial autocorrelation via a Poisson-based multivariate conditional auto-regressive (CAR) framework and is estimated using Bayesian Markov chain Monte Carlo methods. Least-squares regression estimates of walk-miles traveled per zone serve as the exposure measure. Here, the Poisson-lognormal multivariate CAR model outperforms an aspatial Poisson-lognormal multivariate model and a spatial model (without cross-severity correlation), both in terms of fit and inference. Positive spatial autocorrelation emerges across neighborhoods, as expected (due to latent heterogeneity or missing variables that trend in space, resulting in spatial clustering of crash counts). In comparison, the positive aspatial, bivariate cross correlation of severe (fatal or incapacitating) and non-severe crash rates reflects latent covariates that have impacts across severity levels but are more local in nature (such as lighting conditions and local sight obstructions), along with spatially lagged cross correlation. Results also suggest greater mixing of residences and commercial land uses is associated with higher pedestrian crash risk across different severity levels, ceteris paribus, presumably since such access produces more potential conflicts between pedestrian and vehicle movements. Interestingly, network densities show variable effects, and sidewalk provision is associated with lower severe-crash rates. PMID:24036167

  17. The tole of towing services at motor vehicle crashes.

    Science.gov (United States)

    Dean, L; Jame, W; Ryan, G A

    1975-08-16

    A survey of tow truck services operating in a defined area of the south-east suburbs of Melbourne was undertaken to determine their potential for delivering emergency medical care at the scene of crashes. Most towing firms have an association with a panel-beating shop, and operate within a limited area of one to three miles radius. The rapid response of tow trucks to crash scenes is due to their well-developed intelligence network of "spotters" and the short distances the trucks travel. Very little first aid is provided by the drivers, although one-fifth had some first aid training at some time. In about one-half of the calls to crashes a damaged vehicle is still at the scene, in about 20% an ambulance is called, and in about 5% a hospital admission occurs. Direct observation of 22 crashes suggests that on average, tow trucks arrive at a crash scene five minutes before the ambulance, and fifteen minutes before the police. There is a good case for making first aid training a preerequisite for issue of a tow truck operator's license. PMID:1160789

  18. Urban sprawl as a risk factor in motor vehicle crashes

    Science.gov (United States)

    Ewing, Reid; Hamidi, Shima; Grace, James B.

    2016-01-01

    A decade ago, compactness/sprawl indices were developed for metropolitan areas and counties which have been widely used in health and other research. In this study, we first update the original county index to 2010, then develop a refined index that accounts for more relevant factors, and finally seek to test the relationship between sprawl and traffic crash rates using structural equation modelling. Controlling for covariates, we find that sprawl is associated with significantly higher direct and indirect effects on fatal crash rates. The direct effect is likely due to the higher traffic speeds in sprawling areas, and the indirect effect is due to greater vehicle miles driven in such areas. Conversely, sprawl has negative direct relationships with total crashes and non-fatal injury crashes, and these offset (and sometimes overwhelm) the positive indirect effects of sprawl on both types of crashes through the mediating effect of increased vehicle miles driven. The most likely explanation is the greater prevalence of fender benders and other minor accidents in the low speed, high conflict traffic environments of compact areas, negating the lower vehicle miles travelled per capita in such areas.

  19. Human fatigue and the crash of the airship Italia

    Directory of Open Access Journals (Sweden)

    Gregg A. Bendrick

    2016-07-01

    Full Text Available The airship Italia, commanded by General Umberto Nobile, crashed during its return flight from the North Pole in 1928. The cause of the accident was never satisfactorily explained. We present evidence that the crash may have been fatigue-related. Nobile's memoirs indicate that at the time of the crash he had been awake for at least 72 h. Sleep deprivation impairs multiple aspects of cognitive functioning necessary for exploration missions. Just prior to the crash, Nobile made three command errors, all of which are of types associated with inadequate sleep. First, he ordered a release of lift gas when he should have restarted engines (an example of incorrect data synthesis, with deterioration of divergent thinking; second, he inappropriately ordered the ship above the cloud layer (a deficiency in the assessment of relative risks; and third, he remained above the cloud layer for a prolonged period of time (examples of attention to secondary problems, and calculation problems. We argue that as a result of these three errors, which would not be expected from such an experienced commander, there was no longer enough static lift to maintain level flight when the ship went below the cloud layer. Applying Circadian Performance Simulation Software to the sleep–wake patterns described by Nobile in his memoirs, we found that the predicted performance for someone awake as long as he had been is extremely low. This supports the historical evidence that human fatigue contributed to the crash of the Italia.

  20. Mapping Bicycle Crash Risk Patterns on the Local Scale

    Directory of Open Access Journals (Sweden)

    Martin Loidl

    2016-09-01

    Full Text Available Currently, mainly aggregated statistics are used for bicycle crash risk calculations. Thus, the understanding of spatial patterns at local scale levels remains vague. Using an agent-based flow model and a bicycle crash database covering 10 continuous years of observation allows us to calculate and map the crash risk on various spatial scales for the city of Salzburg (Austria. In doing so, we directly account for the spatial heterogeneity of crash occurrences. Additionally, we provide a measure for the statistical robustness on the level of single reference units and consider modifiable areal unit problem (MAUP effects in our analysis. This study is the first of its kind. The results facilitate a better understanding of spatial patterns of bicycle crash rates on the local scale. This is especially important for cities that strive to improve the safety situation for bicyclists in order to address prevailing safety concerns that keep people from using the bicycle as a utilitarian mode of (urban transport.

  1. Real-world car-to-pedestrian-crash data from an urban centre

    Directory of Open Access Journals (Sweden)

    Matthes Gerrit

    2010-02-01

    Full Text Available Abstract Background Pedestrians are at a high risk for crash and injury. This study aims at comparing data from real world crashes with data gathered from experimental settings. Methods IMPAIR (In-Depth Medical Pedestrian Accident Investigation and Reconstruction was a prospective, observational study performed in a metropolitan area. Data was collected on-scene, from clinical records, and interviews. Data comprise crash data, details on injury pattern and injury severity. Results Thirty-seven pedestrians (of which 19 males with a mean 37.1 years of age were included in the study. The mean collision speed was 49.5 km/h (SD 13.7, range, 28 - 93. The mean ISS (31.0, SD 25.4 and the 24% fatality rate indicate a substantial trauma load. The most common AIS 4+ injuries were to the head (23 subjects, followed by chest (8, pelvis (4, and abdomen (2. An association of impact side and injury side (right/left was found for abdominal, chest, pelvic, and upper limb injuries. Primary head impacts were documented on the windscreen (19 subjects, hood (10, A-pillar (2, and edge of the car roof (2. With bivariate analysis, a significant increase of MAIS 4+ head injury risk was found for collision speeds of >40 km/h (OR 9.00, 95% CI 1.96-41.36. Conclusion The real-world data from this study is in agreement with previous findings from biomechanical models and other simulations. This data suggest that there may be reason to include further pedestrian regulations in EuroNCAP.

  2. Option pricing during post-crash relaxation times

    Science.gov (United States)

    Dibeh, Ghassan; Harmanani, Haidar M.

    2007-07-01

    This paper presents a model for option pricing in markets that experience financial crashes. The stochastic differential equation (SDE) of stock price dynamics is coupled to a post-crash market index. The resultant SDE is shown to have stock price and time dependent volatility. The partial differential equation (PDE) for call prices is derived using risk-neutral pricing. European call prices are then estimated using Monte Carlo and finite difference methods. Results of the model show that call option prices after the crash are systematically less than those predicted by the Black-Scholes model. This is a result of the effect of non-constant volatility of the model that causes a volatility skew.

  3. Estimating national road crash fatalities using aggregate data.

    Science.gov (United States)

    Ahmed, Anwaar; Khan, Beenish Akbar; Khurshid, Muhammad Bilal; Khan, Muhammad Babar; Waheed, Abdul

    2016-09-01

    Injuries and fatalities from road traffic crashes have emerged a major public health challenge in Pakistan. Reliable estimates of road crash fatalities (RCF) of a country, is a vital element needed for identification and control of key risk factors, road-safety improvement efforts and prioritizing national health. Reliability of current annual RCF estimates for Pakistan becomes highly questionable due to serious underreporting. This study aimed to predict annual RCF for Pakistan using data from World Health Organization and International Road Federation sources. An ordinary least square (OLS) regression model that relates fatality rate with different explanatory variables was developed. RCF were predicted for Pakistan for year 2012 and 2013, and results were compared with national police reported estimates. Study results indicated that there is serious underreporting of RCF in Pakistan and immediate measures are needed to improve the existing road crash recording and reporting system at the national and subnational levels. PMID:25571957

  4. Car Crash Risk May Nearly Double in People Prone to Fainting

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_157512.html Car Crash Risk May Nearly Double in People Prone to ... as likely as others to get into a car crash, a new study finds. The researchers say the ...

  5. Drowsiness, counter-measures to drowsiness, and the risk of a motor vehicle crash

    OpenAIRE

    Cummings, P; Koepsell, T; Moffat, J; Rivara, F

    2001-01-01

    Objectives—Knowledge of how different indicators of drowsiness affect crash risk might be useful to drivers. This study sought to estimate how drowsiness related factors, and factors that might counteract drowsiness, are related to the risk of a crash.

  6. Crash Risk Soars When Truck Drivers Don't Treat Sleep Apnea

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_157882.html Crash Risk Soars When Truck Drivers Don't Treat ... their treatment program are much more likely to crash, a new study finds. "The most surprising result ...

  7. Pot-Linked Fatal Car Crashes Doubled in One State After Legalization

    Science.gov (United States)

    ... news/fullstory_158760.html Pot-Linked Fatal Car Crashes Doubled in One State After Legalization Experts say ... 2016 (HealthDay News) -- The number of fatal car crashes involving marijuana more than doubled after Washington state ...

  8. A different perspective on conspicuity related motorcycle crashes.

    Science.gov (United States)

    de Craen, Saskia; Doumen, Michelle J A; van Norden, Yvette

    2014-02-01

    The most common type of conflict in which a motorcyclist is injured or killed is a collision between a motorcycle and a car, often in priority situations. Many studies on motorcycle safety focus on the question why car drivers fail to give priority and on the poor conspicuity of motorcycles. The concept of 'looked-but-failed-to-see' crashes is a recurring item. On the other hand, it is not entirely unexpected that motorcycles have many conflicts with cars; there simply are so many cars on the road. This paper tries to unravel whether - acknowledging the differences in exposure - car drivers indeed fail to yield for motorcycles more often than for other cars. For this purpose we compared the causes of crashes on intersections (e.g. failing to give priority, speeding, etc.) between different crash types (car-motorcycle or car-car). In addition, we compared the crash causes of dual drivers (i.e. car drivers who also have their motorcycle licence) with regular car drivers. Our crash analysis suggests that car drivers do not fail to give priority to motorcycles relatively more often than to another car when this car/motorcycle approaches from a perpendicular angle. There is only one priority situation where motorcycles seem to be at a disadvantage compared to cars. This is when a car makes a left turn, and fails to give priority to an oncoming motorcycle. This specific crash scenario occurs more often when the oncoming vehicle is a motorcycle than when it is a car. We did not find a significant difference between dual drivers and regular car drivers in how often they give priority to motorcycles compared to cars. PMID:24291070

  9. Cyclists and drivers in road interactions: A comparison of perceived crash risk

    OpenAIRE

    CHAURAND, Nadine; Delhomme, Patricia

    2013-01-01

    Today’s increase in the number of cyclists has triggered a change in the interactions to be handled by road users. However, few studies have investigated crash risk perceived by cyclists interacting with other users, and few have compared cyclists’ and drivers’ perceptions of crash risk in bike–car interactions,the most dangerous situation for cyclists. Our aims here are to study perceived crash risk (no matter the seriousness of the crash) in six common road situation...

  10. Analysis of NTSB Aircraft-Assisted Pilot Suicides: 1982-2014.

    Science.gov (United States)

    Politano, P Michael; Walton, Robert O

    2016-04-01

    On March 24, 2015, a Germanwings aircraft crashed in the Alps. The suicidal copilot killed himself and 150 others. Pilot suicide is rare, but does happen. This research analyzed the National Transportation Safety Board's accident database (eADMS) looking for pilots who died by suicide in flight. Fifty-one suicides were identified. Gender, age, and other characteristics were examined. Average age of suicidal pilots was 38, significantly different from the average age of 45 for all male pilots involved in aircraft accidents. A discriminant function accurately identified suicidal incidents at 96%. There was a high false-positive rate limiting the usefulness of the discriminant function. PMID:27094027

  11. The analysis of the containment building for global effects of an aircraft crash

    International Nuclear Information System (INIS)

    The aim of the analysis was to establish the displacement and stress states for the whole building in four time points during the transient as well as determine the acceleration time histories, and acceleration response spectra for five points inside the containment building. The five points inside the containment were located between the foundation slab and the upper edge of the containment building. The total amount of nodal points in the model was 800 and the total amount of degrees of freedom was 4300; the amount of quadrilateral shell elements was 900. STARDYNE AND SAPOV programs and direct integration were used for analysis. As for the results of the analysis the following statements can be made: The results calculated by SAPIV and STARDYNE programs are essentially identical. Only the more refined LCCT-11 shell element used in STARDYNE instead of LCCT-9 element used in SAPIV causes the STARDYNE model to be more flexible and this shows in the response histories as a certain phase lag. STARDYNE response leaves gradually behind SAPIV response. The unexpected thing in acceleration responses was that the response in horizontal direction perpendicular to the load application direction was twice as large as the acceleration response in load application direction. (orig./HP)

  12. 78 FR 53386 - Federal Motor Vehicle Safety Standards; Occupant Crash Protection

    Science.gov (United States)

    2013-08-29

    ... 20 mph to 25 mph rigid barrier crash test (65 FR 30680). \\11\\ On September 2, 1993, NHTSA amended... considering unbelted crash test requirements date back to the 1970s (35 FR 16927).\\14\\ To do so without a...; Occupant Crash Protection AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT....

  13. Research on Emerging and Descending Aircraft Noise

    OpenAIRE

    Monika Bartkevičiūtė; Raimondas Grubliauskas

    2013-01-01

    Along with an increase in the aircraft engine power and growth in air traffic, noise level at airports and their surrounding environs significantly increases. Aircraft noise is high level noise spreading within large radius and intensively irritating the human body. Air transport is one of the main sources of noise having a particularly strong negative impact on the environment. The article deals with activities and noises taking place in the largest nationwide Vilnius International Airport.T...

  14. Aging aircraft wiring: a proactive management methodology

    OpenAIRE

    Tambouratzis, Vasileios.

    2001-01-01

    During the last years, military budgets have been dramatically reduced and the services have been unable to acquire sufficient new systems. Military aviation is one of the areas that have been severely impacted. The result is that the current fleet faces significant aging aircraft problems. Aircraft wiring is one of the areas that have severely affected by the aging process. Recent accidents involving aging wiring problems and reduced operational readiness due to aging wiring have made clear ...

  15. Crashworthiness of composite seats for civil aircraft

    OpenAIRE

    Stephens, V. M.

    1992-01-01

    A study has been conducted into the design of civil aircraft seats which are forward-facing and use the lap-belt method of restraint. Within these terms of reference, the response of the seat restraint occupant system (SROS) to impact loading has been analysed using physical (dynamic testing) and analytical (computer simulation) modelling techniques. With the increasing use of fibre-reinforced polymer composites in aircraft for weight efficiency, and the consequent appearance of composite se...

  16. Numerical simulation on response and damage of nuclear containment under aircraft impact%飞机对核安全壳撞击破坏效应的数值模拟

    Institute of Scientific and Technical Information of China (English)

    张涛; 方秦; 吴昊; 龚自明

    2014-01-01

    To analyze the damage failure of the nuclear containment under the impact of large aircrafts, the refined finite element models of aircraft A320 and the Lingao nuclear containment were established. The process of the im-pact was simulated by using the commercial finite element software LS-DYNA. The results show that there are three noticeable peaks in the process, corresponding to the impact of the cockpit, engines and wings( fuel tank) respec-tively. The maximum peak load is mainly caused by the impact of the engines. Compared with other related litera-tures, the impact load-time curve is similar. But the time duration and the peak load are obviously different for the differences of the aircraft type, mass and impacting velocity. Under the take-off and landing velocity of 100 m/s, containment is seriously damaged and the impacting centre suffers localized perforation, very probably leading to nuclear leakage.%为了研究大型商用客机撞击核电站安全壳的破坏效应,通过建立精细化的空客A320以及岭澳核电站安全壳有限元模型,采用LS-DYNA软件对飞机撞击安全壳进行了数值模拟。分析结果表明:A320撞击力时程曲线出现3次明显的峰值,分别对应驾驶舱、引擎以及机翼(油箱)受撞击产生,其中引擎撞击导致最大峰值荷载。得到的撞击力时程曲线形状与已有研究结论相似,但因飞机型号、质量及撞击速度不同,撞击持续时间、峰值荷载大小及出现时刻存在明显差别。在飞机速度为100 m/s撞击下安全壳损伤严重,撞击中心发生局部穿透并很有可能引发核泄漏。

  17. Thermal performance of aircraft polyurethane seat cushions

    Science.gov (United States)

    Kourtides, D. A.; Parker, J. A.

    1982-01-01

    Measurements were conducted on 7.6 x 7.6 cm samples of polyurethane seat cushion material in a modified National Bureau of Standards smoke density chamber to simulate real life conditions for an onboard aircraft fire or post-crash fire. In this study, a non-flaming heat radiation condition was simulated. Two aluminized polymeric fabrics (Norfab 11HT-26-A and Preox 1100-4) and one neoprene type material in two thicknesses (Vonar 2 and 3) were tested as heat blocking layers to protect the urethane foam from rapid heat degradation. Thermogravimetric analysis and differential scanning calorimetry were performed to characterize thermally the materials tested. It was found that Vonar 2 or 3 provided approximately equal thermal protection to F.R. urethane as the aluminized fabrics, but at a significant weight penalty. The efficiency of the foams to absorb heat per unit mass loss when protected with the heat blocking layer decreases in the heating range of 2.5-5.0 W/sq cm, but remains unchanged or slightly increases in the range of 5.0-7.5 W/sq cm. The results show that at all heat flux ranges tested the usage of a heat blocking layer in aircraft seats significantly improves their thermal performance.

  18. Two-fractal overlap time series: Earthquakes and market crashes

    Indian Academy of Sciences (India)

    Bikas K Chakrabarti; Arnab Chatterjee; Pratip Bhattacharyya

    2008-08-01

    We find prominent similarities in the features of the time series for the (model earthquakes or) overlap of two Cantor sets when one set moves with uniform relative velocity over the other and time series of stock prices. An anticipation method for some of the crashes have been proposed here, based on these observations.

  19. Car-Crash Experiment for the Undergraduate Laboratory

    Science.gov (United States)

    Ball, Penny L.; And Others

    1974-01-01

    Describes an interesting, inexpensive, and highly motivating experiment to study uniform and accelerated motion by measuring the position of a car as it crashes into a rigid wall. Data are obtained from a sequence of pictures made by a high speed camera. (Author/SLH)

  20. Crash simulations of wheelchair-occupant systems in transport.

    Science.gov (United States)

    Kang, W; Pilkey, W D

    1998-01-01

    A nonlinear multirigid body dynamic computer model has been developed to simulate the dynamic responses of a wheelchair-occupant system in a vehicle during a crash. The occupant, restrained by safety belts, is seated in a wheelchair that is, in turn, tied down in a vehicle. Validated extensively by crash sled tests at three laboratories, this model has been used to predict the responses of wheelchair-occupant systems in various crash environments. To evaluate the crashworthiness of different wheelchair tie-downs, the sensitivity of several design parameters, such as tiedown stiffness, wheel stiffness, and tiedown positions, has been studied using this model, and optimal values of these parameters for the wheelchair-occupant system have been obtained. Moreover, the model has been used to study the sensitivity of crash sled test pulse corridors in an effort to develop a sled test standard. It has been found that an existing ISO corridor allows large variation and should be "tightened." The model was implemented using a version of the multibody dynamic simulator, the Articulated Total Body program. PMID:9505255