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Sample records for 3d cmm strain-gauge

  1. 3D CMM Strain-Gauge Triggering Probe Error Characteristics Modeling

    Achiche, Sofiane; Wozniak, Adam; Fan, Zhun;

    2008-01-01

    The error values of CMMs depends on the probing direction; hence its spatial variation is a key part of the probe inaccuracy. This paper presents genetically-generated fuzzy knowledge bases (FKBs) to model the spatial error characteristics of a CMM module-changing probe. Two automatically generat...

  2. 3D CMM strain-gauge triggering probe error characteristics modeling using fuzzy logic

    Achiche, Sofiane; Wozniak, A; Fan, Zhun;

    2008-01-01

    The error values of CMMs depends on the probing direction; hence its spatial variation is a key part of the probe inaccuracy. This paper presents genetically-generated fuzzy knowledge bases (FKBs) to model the spatial error characteristics of a CMM module-changing probe. Two automatically generat...

  3. Package analysis of 3D-printed piezoresistive strain gauge sensors

    Das, Sumit Kumar; Baptist, Joshua R.; Sahasrabuddhe, Ritvij; Lee, Woo H.; Popa, Dan O.

    2016-05-01

    Poly(3,4-ethyle- nedioxythiophene)-poly(styrenesulfonate) or PEDOT:PSS is a flexible polymer which exhibits piezo-resistive properties when subjected to structural deformation. PEDOT:PSS has a high conductivity and thermal stability which makes it an ideal candidate for use as a pressure sensor. Applications of this technology includes whole body robot skin that can increase the safety and physical collaboration of robots in close proximity to humans. In this paper, we present a finite element model of strain gauge touch sensors which have been 3D-printed onto Kapton and silicone substrates using Electro-Hydro-Dynamic ink-jetting. Simulations of the piezoresistive and structural model for the entire packaged sensor was carried out using COMSOLR , and compared with experimental results for validation. The model will be useful in designing future robot skin with predictable performances.

  4. A novel ultrasonic strain gauge for single-sided measurement of a local 3D strain field

    Kersemans, Mathias; Allaer, Klaas; Paepegem, Wim Van; Van Den Abeele, Koen; Pyl, Lincy; Zastavnik, Filip; Sol, Hugo; Degrieck, Joris

    2014-01-01

    A novel method is introduced for the measurement of a 3D strain field by exploiting the interaction between ultrasound waves and geometrical characteristics of the insonified specimen. First, the response of obliquely incident harmonic waves to a deterministic surface roughness is utilized. Analysis of backscattered amplitudes in Bragg diffraction geometry then yields a measure for the in-plane strain field by mapping any shift in angular dependency. Secondly, the analysis of the reflection c...

  5. Program Calibrates Strain Gauges

    Okazaki, Gary D.

    1991-01-01

    Program dramatically reduces personnel and time requirements for acceptance tests of hardware. Data-acquisition system reads output from Wheatstone full-bridge strain-gauge circuit and calculates strain by use of shunt calibration technique. Program nearly instantaneously tabulates and plots strain data against load-cell outputs. Modified to acquire strain data for other specimens wherever full-bridge strain-gauge circuits used. Written in HP BASIC.

  6. Trials with a Strain Gauge.

    Auty, Geoff

    1996-01-01

    Describes an attempt to match the goals of the practical demonstration of the use of a strain gauge and the technical applications of science and responding to student questions in early trials, while keeping within the level of electronics in advanced physics. (Author/JRH)

  7. Temperature-Compensating Inactive Strain Gauge

    Moore, Thomas C., Sr.

    1993-01-01

    Thermal contribution to output of active gauge canceled. High-temperature strain gauges include both active gauge wires sensing strains and inactive gauge wires providing compensation for thermal contributions to gauge readings. Inactive-gauge approach to temperature compensation applicable to commercially available resistance-type strain gauges operating at temperatures up to 700 degrees F and to developmental strain gauges operating at temperatures up to 2,000 degrees F.

  8. Strain gauges as intrusion detection sensors

    Strain gauges have been studied for use as intrusion detection sensors in several applications being investigated at Sandia National Laboratories. Strain gauges are attached to a metal structure to monitor the quiescent strain in the structure. The change in the quiescent strain, when an intruder adds weight to the structure provides the alarm mechanism. The basic theory of force sensors is covered to lay the foundation for this application. In this paper, how this basic theory is applied to security sensors is discussed, and how this class of sensors is applicable to security at Department of Energy facilities is covered. Several applications are described for strain gauges as security sensors. Test results are presented from a six-month test conducted at a Department of Energy facility using the strain gauge to monitor overhead lines crossing a security perimeter. Monitoring these overhead lines with strain gauges is valuable because the cost is much less than the cost to bury the lines

  9. Dynamic Force Measurement with Strain Gauges

    Lee, Bruce E.

    1974-01-01

    Discusses the use of four strain gauges, a Wheatstone bridge, and an oscilloscope to measure forces dynamically. Included is an example of determining the centripetal force of a pendulum in a general physics laboratory. (CC)

  10. Strain Gauges Mounted To Retain Calibration

    Butler, Barry L.

    1993-01-01

    Silicon-based semiconductor strain gauges mounted in such way they retain original calibration for several years instead of few months. Improvement effected by bonding gauges to ceramic substrates with glasses instead of epoxies as adhesives.

  11. Hydraulic Calibrator for Strain-Gauge Balances

    Skelly, Kenneth; Ballard, John

    1987-01-01

    Instrument for calibrating strain-gauge balances uses hydraulic actuators and load cells. Eliminates effects of nonparallelism, nonperpendicularity, and changes of cable directions upon vector sums of applied forces. Errors due to cable stretching, pulley friction, and weight inaccuracy also eliminated. New instrument rugged and transportable. Set up quickly. Developed to apply known loads to wind-tunnel models with encapsulated strain-gauge balances, also adapted for use in calibrating dynamometers, load sensors on machinery and laboratory instruments.

  12. The Strain Gauge Plethysmograph For Polysomnography

    Vondra, Vlastimil; Kára, T.; Jurák, Pavel

    Brno : Brno University of Technology , 2004, s. 211-213. ISBN 80-214-2633-0. ISSN 1211-412X. [Biosignal 2004 /17./. Brno (CZ), 23.06.2004-25.06.2004] R&D Projects: GA ČR GA102/02/1339 Keywords : Strain Gauge Plethysmograph * Polysomnography Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  13. Nanocomposite Strain Gauges Having Small TCRs

    Gregory, Otto; Chen, Ximing

    2009-01-01

    Ceramic strain gauges in which the strain-sensitive electrically conductive strips made from nanocomposites of noble metal and indium tin oxide (ITO) are being developed for use in gas turbine engines and other power-generation systems in which gas temperatures can exceed 1,500 F (about 816 C). In general, strain gauges exhibit spurious thermally induced components of response denoted apparent strain. When temperature varies, a strain-gauge material that has a nonzero temperature coefficient of resistance (TCR) exhibits an undesired change in electrical resistance that can be mistaken for the change in resistance caused by a change in strain. It would be desirable to formulate straingauge materials having TCRs as small as possible so as to minimize apparent strain. Most metals exhibit positive TCRs, while most semiconductors, including ITO, exhibit negative TCRs. The present development is based on the idea of using the negative TCR of ITO to counter the positive TCRs of noble metals and of obtaining the benefit of the ability of both ITO and noble metals to endure high temperatures. The noble metal used in this development thus far has been platinum. Combinatorial libraries of many ceramic strain gauges containing nanocomposites of various proportions of ITO and platinum were fabricated by reactive co-sputtering from ITO and platinum targets onto alumina- and zirconia-based substrates mounted at various positions between the targets.

  14. Influence of nuclear radiation on strain gauges

    The influence of nuclear radiation on strain gauges is a superposition of a primary effect (generation of lattice defects resulting in an increase of resistance), a secondary effect (caused by radiation induced diffusion, which - depending on the material and its prior thermodynamic state - leads to a decrease or increase of resistance) and an after-effect (change of resistance after irradiation or between irradiations). The consequences of these effects depend on different parameters with mudual dependencies. Conclusion: Single strain gauges (quarter bridges) should not be used under nuclear radiation; the multitouch of - usually unknown - influence parameters makes a general prediction of the behaviour under radiation practically impossible. Particularly, it is impossible to apply methods such as choice of special materials or pretreatment procedures in order to get strain gauges for high radiation rates. Strain gauges in half-bridge configuration give - under optimum conditions a small difference of two large interfering quantities, which can hardly be estimated. Thus a prognosis of the performance under radiation remains doubtful. With 26 figs., 1 tab

  15. Lewis Strain Gauge Laboratory: Status and plans

    An in-house lab was established for developing, testing, and evaluating high-temperature strain gauges and to aid in in-house applications of high-temperature strain instrumentation. The lab is automated to provide computer control of oven temperatures, imposed strain, and data sampling

  16. High-Temperature Resistance Strain Gauges

    Lei, Jih-Fen

    1994-01-01

    Resistance strain gauges developed for use at high temperatures in demanding applications like testing aircraft engines and structures. Measures static strains at temperatures up to 800 degrees C. Small and highly reproducible. Readings corrected for temperature within small tolerances, provided temperatures measured simultaneously by thermocouples or other suitable devices. Connected in wheatstone bridge.

  17. Strain gauge for high temperature tests

    A strain gauge is described that is intended to measure longitudinal and lateral strains during tubular specimen loading by an axial force and internal pressure at test temperatures up to 1000 K. The use of the gauge for creep study of steel type Kh18N10T at 870 K under complex stress state is given as an example. Experimental data confirm the suitability of the gauge for the purpose mentioned and sufficient accuracy of parameters determined. 3 refs., 3 figs

  18. Weighing of heavy vessels using strain gauges

    The effect of pressure and temperature fluctuations is greatly reduced by appropriate design and by prestressing of the lines in an apparatus for remote, continuous weighing of heavy pressurized vessels (60 bar) at high temperatures (2500C), even when these vessels are connected to other systems by means of metal lines. The weighing device is based on the application of strain gauges. The accuracy of measurement is within 0.5%. Weighing devices of this type can be applied, for example, in the process industry

  19. Film germanium strain gauges for cryogenic temperatures

    Strain-measuring characteristics of strain gauges (SG) based on germanium films on gallium arsenide designed for operation in 4-100 K temperature interval and strain range ε∼(±0.3%) are presented. SG are characterized by weak temperature dependences of resistance and strain sensitivity in the temperature range measured. It is shown that in the low-temperature region SG based on heteroepitaxial germanium films on gallium arsenide are no worse than the best domestic and foreign semiconducting and metal SG and are perspective for cryogenic object diagnostics under magnetic field effect

  20. Low-temperature strain gauges based on silicon whiskers

    Druzhinin A. A.; Maryamova I. I.; Kutrakov A. P.; Pavlovskyy I. V.

    2008-01-01

    To create low-temperature strain gauges based on p-type silicon whiskers tensoresistive characteristics of these crystals in 4,2—300 K temperature range were studied. On the basis of p-type Si whiskers with different resistivity the strain gauges for different materials operating at cryogenic temperatures with extremely high gauge factor at 4,2 K were developed, as well as strain gauges operating at liquid helium temperatures in high magnetic fields.

  1. Low-temperature strain gauges based on silicon whiskers

    Druzhinin A. A.

    2008-08-01

    Full Text Available To create low-temperature strain gauges based on p-type silicon whiskers tensoresistive characteristics of these crystals in 4,2—300 K temperature range were studied. On the basis of p-type Si whiskers with different resistivity the strain gauges for different materials operating at cryogenic temperatures with extremely high gauge factor at 4,2 K were developed, as well as strain gauges operating at liquid helium temperatures in high magnetic fields.

  2. The dual element method of strain gauge temperature compensation

    Englund, David R.

    1987-01-01

    The use of a known temperature compensation technique is suggested to reduce the overall temperature sensitivity of a PdCr strain gauge system being developed for turbine engine research. The temperature compensation technique proposed for this application uses a resistance thermometer in an adjacent leg of the strain gauge bridge circuit to cancel the thermally generated resistance change of the strain gauge. Equations for calculating the required compensation resistor values and the sensitivity of the resulting strain gauge bridge to both temperature and strain are presented.

  3. Inexpensive Implementation of Many Strain Gauges

    Berkun, Andrew C.

    2010-01-01

    It has been proposed to develop arrays of strain gauges as arrays of ordinary metal film resistors and associated electronic readout circuitry on printed circuit boards or other suitable substrates. This proposal is a by-product of a development of instrumentation utilizing metal film resistors on printed-circuit boards to measure temperatures at multiple locations. In the course of that development, it was observed that in addition to being sensitive to temperature, the metal film resistors were also sensitive to strains in the printed-circuit boards to which they were attached. Because of the low cost of ordinary metal film resistors (typically strain gauges, possibly concentrated in small areas. For example, such an array could be designed for use as a computer keyboard with no moving parts, as a device for sensing the shape of an object resting on a surface, or as a device for measuring strains at many points on a mirror, a fuel tank, an airplane wing, or other large object. Ordinarily, the effect of strain on resistance would be regarded as a nuisance in a temperature-measuring application, and the effect of temperature on resistance would be regarded as a nuisance in a strain-measuring application. The strain-induced changes in resistance of the metal film resistors in question are less than those of films in traditional strain gauges. The main novel aspect of present proposal lies in the use of circuitry affording sufficient sensitivity to measure strain plus means for compensating for the effect of temperature. For an array of metal film resistors used as proposed, the readout circuits would include a high-accuracy analog-to-digital converter fed by a low noise current source, amplifier chain, and an analog multiplexer chain. Corrections would be provided by use of high-accuracy calibration resistors and a temperature sensor. By use of such readout circuitry, it would be possible to read the resistances of as many as 100 fixed resistors in a time interval

  4. Influence of nuclear radiation on strain gauges

    The examination of safety of nuclear reactor components requires strain measurements on parts of constructions while operating and this means when influenced by nuclear radiation. As strain gauges are the most applied devices for strain measurement and very suitable in respect to their handling, the influence of nuclear radiation has been investigated for the first time more than 30 years ago in order to obtain information on the reliability of measuring results in such difficult environmental conditions. Since that time only some papers have been published dealing with the progress in this field of measuring technics. A generally valid statement however could not be obtained yet. The effect of 10 MeV electron irradiation on the specific resistivity has been studied. (orig./HP)

  5. Pile Model Tests Using Strain Gauge Technology

    Krasiński, Adam; Kusio, Tomasz

    2015-09-01

    Ordinary pile bearing capacity tests are usually carried out to determine the relationship between load and displacement of pile head. The measurement system required in such tests consists of force transducer and three or four displacement gauges. The whole system is installed at the pile head above the ground level. This approach, however, does not give us complete information about the pile-soil interaction. We can only determine the total bearing capacity of the pile, without the knowledge of its distribution into the shaft and base resistances. Much more information can be obtained by carrying out a test of instrumented pile equipped with a system for measuring the distribution of axial force along its core. In the case of pile model tests the use of such measurement is difficult due to small scale of the model. To find a suitable solution for axial force measurement, which could be applied to small scale model piles, we had to take into account the following requirements: - a linear and stable relationship between measured and physical values, - the force measurement accuracy of about 0.1 kN, - the range of measured forces up to 30 kN, - resistance of measuring gauges against aggressive counteraction of concrete mortar and against moisture, - insensitivity to pile bending, - economical factor. These requirements can be fulfilled by strain gauge sensors if an appropriate methodology is used for test preparation (Hoffmann [1]). In this paper, we focus on some aspects of the application of strain gauge sensors for model pile tests. The efficiency of the method is proved on the examples of static load tests carried out on SDP model piles acting as single piles and in a group.

  6. 纳米坐标测量机的三维接触式测头机构%Research on the 3D Touch Probe Mechanism of Nano-CMM

    刘芳芳; 费业泰; 夏豪杰

    2011-01-01

    介绍了一种新型的用于纳米坐标测量机的三维微纳米接触触发式测头机构.本测头以灵敏度高、抗干扰性强的布拉格光纤光栅(FBG)为测量的敏感元件,根据FBG对轴向应变变化敏感的特点,开发了一套有效触发测量力小的柔性悬架机构,该机构为三悬丝-六边中心连接体的悬架结构,相间隔的3边延伸悬臂与3根布拉格光纤光栅相连,当测球发生预行程变化时,由测杆带动柔性悬架机构产生偏摆,从而带动3根FBG发生轴向的拉伸或压缩,进而产生传感信号的输出.由于测头结构复位性是衡量测球和工件分离后能否回到初始位置的标准,是测头其他各项指标的基础,因此结合激光干涉仪和精密微动平台,采用光学非接触干涉测量方法对该测头机构的实际复位性能进行了测量.结果表明,测头系统采用15 N的预紧力安装悬丝,可得到较好的复位性和灵敏度,该测头机构复位性精度在20nm以内,满足微纳米量级高精度测量的需要.%A novel micro-nano touch trigger 3D probe of coordinate measuring machine (CMM) was proposed.Based on the high sensitivity and good anti-interference of fiber Bragg grating (FBG) sensor,FBG sensors were used as sensitive elements for the probe to measure the strain produced along the fiber.As FBG sensors were more sensitive to axial strain than to lateral strain, a flexible structure consisting of the three-wire and six-side connecting hanging structure with interval cantilevers connected with three FBG sensors was developed, which could be triggered by small strain produced by effective axial force.In case of pre-travel changes, flexible suspension caused deflection, leading to axial stretch or compression of the three FBG sensors, and thus the sensor signal output.The reposition performance of the probe mechanism is the criteria for judging whether it can go back to the initial location after measuring and is the basis of other

  7. Fabrication and mechanical characterisation of inkjet printed strain gauges

    Visser, H.A.; Balda Irurzun, U.; Akkerman, R.; Sridhar, A.

    2011-01-01

    The present study focuses on printing strain sensors directly on tensile test specimens using inkjet printing technology. This type of strain gauges has the advantage over conventional strain gauges that no glue or carrying platelet is present between the sensor and the surface that should be measur

  8. More About High-Temperature Resistance Strain Gauges

    Englund, D. R.; Williams, W. D.; Lei, Jih-Fen; Hulse, C. O.

    1994-01-01

    Two reports present additional information on electrical-resistance strain gauges described in "High-Temperature Resistance Strain Gauges" (LEW-15379). For protection against oxidation at high temperatures, gauges covered, by flame spraying, with coats of alumina containing up to 1 weight percent of yttria or, perferably, containing 4 to 6 weight percent of zirconia.

  9. Improved method of SSC strain gauge calibration at cryogenic temperatures

    The development of an improved strain gauge calibration station for the SSC dipole magnets will have several advantages. The new design will use significantly less helium, provide for a much higher productivity, and will generate completely automated calibration reports. This will be accomplished by having a finer control over the press pressures, prechilling of the transducers, changing the calibrated transducers for uncalibrated transducers without frosting or warming the press, and the possibility of recovering the spent helium. Five main components make up the system: (1) Test Vessel - non-pressurized cryogenic vessel where the strain gauges are calibrated; (2) Precool Vessel - non-pressurized cryogenic vessel where six strain gauge fixtures are placed for precooling; (3) Fixture - used to hold the two strain gauges that are being calibrated; (4) Hydraulics - dual stage air-over-oil system controlled by an electronic-pneumatic valve; and (5) Computer - controls the electronic-pneumatic valve and records all the readings to calibrate the strain gauges

  10. CMM Interim Check (U)

    Montano, Joshua Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-23

    Coordinate Measuring Machines (CMM) are widely used in industry, throughout the Nuclear Weapons Complex and at Los Alamos National Laboratory (LANL) to verify part conformance to design definition. Calibration cycles for CMMs at LANL are predominantly one year in length. Unfortunately, several nonconformance reports have been generated to document the discovery of a certified machine found out of tolerance during a calibration closeout. In an effort to reduce risk to product quality two solutions were proposed – shorten the calibration cycle which could be costly, or perform an interim check to monitor the machine’s performance between cycles. The CMM interim check discussed makes use of Renishaw’s Machine Checking Gauge. This off-the-shelf product simulates a large sphere within a CMM’s measurement volume and allows for error estimation. Data was gathered, analyzed, and simulated from seven machines in seventeen different configurations to create statistical process control run charts for on-the-floor monitoring.

  11. Study of silicon strain gauges under electron irradiation

    Liakh-Kaguj N. S.; Masluk V. T.; Kutrakov A. P.; Maryamova I. I.; Druzhinin A. A.; Mehela I. G.

    2010-01-01

    The characteristics of semiconductor strain gauges based on boron doped р-type silicon whiskers under high energy electron irradiation were studied. Strain gauges were irradiated at room temperature by electrons with energies 4,2—14 MeV and different doses 5·1016—1·1018 el/cm2. The main parameters of irradiated strain gauges: resistance, its temperature dependence and resistance change vs strain at –196…+100°C and –269…+20°C temperature ranges were measured. There are determined the values of...

  12. From Measurements Errors to a New Strain Gauge Design

    Mikkelsen, Lars Pilgaard; Zike, Sanita; Salviato, Marco;

    2015-01-01

    Significant over-prediction of the material stiffness in the order of 1-10% for polymer based composites has been experimentally observed and numerical determined when using strain gauges for strain measurements instead of non-contact methods such as digital image correlation or less stiff methods...... such as clip-on extensometers. In the present work, this has been quantified through a numerical study for three different strain gauges. In addition, a significant effect of a thin polymer coating or biaxial layer in the erroneous using strain gauges has been observed. An erroneous which can be...

  13. Method of tuning a strain gauge full bridge

    In the strain gauge full bridge consisting of four narrow bridge branches acting as strain gauges a change in cross section of the broadened conductor area between the strain gauges is made. This is achieved by means of a focused laser beam, preferably by using it to cut a gap in the conductor area. This allows the bridge to be tuned extremely finely because the development of the gap can be controlled as a function of the bridge output signal during the cutting procedure. Hence, small changes in resistivity of the broadened conductor area can be achieved in this way. (DG)

  14. Study of silicon strain gauges under electron irradiation

    Liakh-Kaguj N. S.

    2010-02-01

    Full Text Available The characteristics of semiconductor strain gauges based on boron doped р-type silicon whiskers under high energy electron irradiation were studied. Strain gauges were irradiated at room temperature by electrons with energies 4,2—14 MeV and different doses 5·1016—1·1018 el/cm2. The main parameters of irradiated strain gauges: resistance, its temperature dependence and resistance change vs strain at –196…+100°C and –269…+20°C temperature ranges were measured. There are determined the values of electron irradiation energy and dose at which the radiation stability of strain gauges could be ensured.

  15. ANALYSIS OF THE ACCURACY OF FIBRE-OPTIC STRAIN GAUGES

    Dita Jiroutová

    2013-12-01

    Full Text Available In recent years, the field of structure monitoring has been making increasing use of systems based on fiber-optic technologies. Fiber-optic technology offers many advantages, including higher quality measurements, greater reliability, easier installation and maintenance, insensitivity to the environment (mainly to the electromagnetic field, corrosion resistance, safety in explosive and flammable environments, the possibility of long-term monitoring and lower cost per lifetime. We have used SOFO fibre-optic strain gauges to perform measurements to check the overall relative deformation of a real reinforced concrete structure. Long-term monitoring of the structure revealed that the measurement readings obtained from these fibre-optic strain gauges differed from each other. Greater attention was therefore paid to the calibration of the fibre-optic strain gauges, and to determining their measurement accuracy. The experimental results show that it is necessary to calibrate SOFO strain gauges before they are used, and to determine their calibration constant.

  16. Strain gauge sensitivity improved by using a composite beam

    Silver, R. H.; Kalfayan, S. H.

    1975-01-01

    Composite beam connected to strain gauge and mounted on test specimen is capable of amplifying small strains by factor of 10. Tests indicate that resulting output can be 10 times greater than standard method.

  17. Characterisation of an Optical Strain Gauge for Pantograph Applications

    R. Khanniche

    2005-09-01

    Full Text Available An optical strain gauge is developed and characterised for an active pantograph for high-speed electrical trains applications. Indeed, the pantograph is subjected to a continuous impact forces when it makes contact with the 25 kV overhead ac line. To detect load behaviour experienced, by the electrical pick-up on the pantograph, tests were carried out. The results show that the strain gauge responded linearly to static load over the range 0 to 80 Newton. Also, a high repeatability was achieved and acceptable amount of hysterisis was experienced. The influence of the electromagnetic field on the optical strain gauge was sufficiently weak to be neglected. Beside that the optical strain gauge has proved a high resistance to time varying forces.

  18. Reliability of PEDOT-PSS Strain Gauge on foam structure

    Chang, Cheng-Ling; Fix, Kayla; Wang, Wei-Chih

    2010-01-01

    Reliability is one important issue in using PEDOT: PSS as a strain gauge for large strain measurements. In our research, PEDOT: PSS strain gauge is fabricated on the polyurethane and porous substrate, which enhances the mechanical property when large strain and cyclic loads are applied to it. Our result shows that with the polyurethane as the substrate adhesion layer, the strain of PEDOT: PSS can go up to 17.7% and stabilize without reference resistance drifting.

  19. Thin-Film Strain Gauge Sensors for Ion Thrust Measurement

    Stephen, John R.; Rajanna, K.; Dhar, Vivek; Kumar, Kalyan KG; Nagabushanam, S

    2004-01-01

    In order to measure the thrust produced by a Stationary Plasma Thruster, a measurement system has been developed using a thrust balance with thin film strain gauge sensors. For this purpose, strain gauges were designed and deposited on the columns of the thrust balance fabricated and necessary signal conditioning circuit has been used. Performance of the system developed was studied, in a vacuum chamber under space simulated conditions, by activating the thruster. In-situ calibration was done...

  20. Improvements In A Laser-Speckle Surface-Strain Gauge

    Lant, Christian T.

    1996-01-01

    Compact optical subsystem incorporates several improvements over optical subsystems of previous versions of laser-speckle surface-strain gauge: faster acquisition of data, faster response to transients, reduced size and weight, lower cost, and less complexity. Principle of operation described previously in "Laser System Measures Two-Dimensional Strain" (LEW-15046), and "Two-Dimensional Laser-Speckle Surface-Strain Gauge" (LEW-15337).

  1. Tunable strain gauges based on two-dimensional silver nanowire networks.

    Ho, Xinning; Cheng, Chek Kweng; Tey, Ju Nie; Wei, Jun

    2015-05-15

    Strain gauges are used in various applications such as wearable strain gauges and strain gauges in airplanes or structural health monitoring. Sensitivity of the strain gauge required varies, depending on the application of the strain gauge. This paper reports a tunable strain gauge based on a two-dimensional percolative network of silver nanowires. By varying the surface coverage of the nanowire network and the waviness of the nanowires in the network, the sensitivity of the strain gauge can be controlled. Hence, a tunable strain gauge can be engineered, based on demands of the application. A few applications are demonstrated. The strain gauge can be adhered to the human neck to detect throat movements and a glove integrated with such a strain gauge can detect the bending of the forefinger. Other classes of two-dimensional percolative networks of one-dimensional materials are also expected to exhibit similar tunable properties. PMID:25902896

  2. Strain Gauges Indicate Differential-CTE-Induced Failures

    Harris, Brian

    2007-01-01

    A method of detecting mechanical failure induced by variation in temperature at an adhesive bond between two materials that have different coefficients of thermal expansion (CTEs) involves monitoring of strain-gauge readings. This method can be regarded as an exploitation of the prior observation that the readings of strain gauges commonly used in tensile and compressive testing of material specimens include features indicative of incremental failures in the specimens. In this method, one or more strain gauges are bonded to either or both of the two materials near the bond between the materials. (The adhesive used to bond the strain gauges would not ordinarily be the same as the one used to bond the two materials). Then strain-gauge readings are recorded as the temperature of the materials is varied through a range of interest. Any significant discontinuity in the slope of the resulting strain-versus-temperature curve(s) is taken to be a qualitative indication of a failure of the bond between the two materials and/or a failure within one of the materials in the vicinity of the bond. The method has been demonstrated in experiments on specimens consisting of polyacrylonitrile-fiber/epoxy-matrix laminated composite plates bonded by epoxy to smaller plates made, variously, of aluminum, titanium, and a low-CTE nickel/iron alloy. In preparation for each experiment, strain gauges were bonded, by use of cryogenic-rated adhesives, to the composite plate near the corners of the metal plate (see Figure 1). In each experiment, strain-gauge and temperature readings were taken as the specimen was cooled from room temperature to 20 K. The specimens were then returned to room temperature and ultrasonically inspected for damage in the bond region. No failure events were detectable in the strain-gauge readings from the composite/ titanium and composite/low-thermalexpansion- alloy specimens, and ultrasonic inspection of these specimens revealed no damage. However, failure events were

  3. Characterisation of an Optical Strain Gauge for Pantograph Applications

    R. Khanniche; Davies, T.; M. S. Khanniche

    2005-01-01

    An optical strain gauge is developed and characterised for an active pantograph for high-speed electrical trains applications. Indeed, the pantograph is subjected to a continuous impact forces when it makes contact with the 25 kV overhead ac line. To detect load behaviour experienced, by the electrical pick-up on the pantograph, tests were carried out. The results show that the strain gauge responded linearly to static load over the range 0 to 80 Newton. Also, a high repeatability was achieve...

  4. Probability characteristics of strain gauges of fatique damage

    The evaluation of damage, taking into account the scattering characteristics of the damage gauges indications, is essential. A method of damage evaluation under low-cycle structure loading, based on the account of the strain gauges indications scattering, is proposed. The variance of gauges indications in the process of low-cycle loading and the variance of their life is taken into account. The criterion equation determining the structures and damage gauges life is taken as a deformation-kinetic criterion. In the probability approach on the example of a pressure vessel, was made an evaluation of the structure with the use of strain gauges of fatigue damage. (orig.)

  5. The Lewis Strain Gauge Laboratory: Status and plans

    Hobart, Howard F.; Will, Herbert A.

    1985-01-01

    An in-house lab was established for developing, testing, and evaluating high-temperature strain gauges and to aid in in-house applications of high-temperature strain instrumentation. The lab is automated to provide computer control of oven temperatures, imposed strain, and data sampling.

  6. Method of attaching strain gauges to various materials

    Schott, Timothy D. (Inventor); Fox, Robert L. (Inventor); Buckley, John D. (Inventor)

    1988-01-01

    A method is provided to bond strain gauges to various materials. First, a tape with an adhesive backing is placed across the inside of the fixture frame. The strain gauge is flatly placed against the adhesive backing and coated with a thin, uniform layer of adhesive. The tape is then removed from the fixture frame and placed, strain gauge side down, on the material to be tested. If the material is a high reluctance material, the induction heating source is placed on the tape. If the material is a low reluctance material, a plate with a ferric side and a rubber side is placed, ferric side down, onto the tape. The induction heating source is then placed upon the rubber side. If the material is an insulator material, a ferric plate is placed on the tape. The induction heating source is then placed on the ferric plate. The inductive heating source then generates frequenty from 60 to 70 kilocycles to inductively heat either low reluctance material, ferric side, of ferric plate and provides incidental pressure of approximately five pounds per square inch to the tape for two minutes, thoroughly curing the adhesive. The induction heating source, and, if necessary, the plate or ferric plate, are then removed from the tape after one minute. The tape is then removed from the bonded strain gauge.

  7. Measuring systolic ankle and toe pressure using the strain gauge technique--a comparison study between mercury and indium-gallium strain gauges

    Broholm, Rikke; Wiinberg, Niels; Simonsen, Lene

    2014-01-01

    BACKGROUND: Measurement of the ankle and toe pressures are often performed using a plethysmograph, compression cuffs and a strain gauge. Usually, the strain gauge contains mercury but other alternatives exist. From 2014, the mercury-containing strain gauge will no longer be available in the...... European Union. The aim of this study was to compare an indium-gallium strain gauge to the established mercury-containing strain gauge. METHODS: Consecutive patients referred to the Department of Clinical Physiology and Nuclear Medicine at Bispebjerg and Frederiksberg Hospitals for measurements of systolic...... ankle and toe pressures volunteered for the study. Ankle and toe pressures were measured twice with the mercury and the indium-gallium strain gauge in random order. Comparison of the correlation between the mean pressure using the mercury and the indium-gallium device and the difference between the two...

  8. Vectorial strain gauge method using single flexible orthogonal polydimethylsiloxane gratings

    Guo, Hao; Tang, Jun; Qian, Kun; Tsoukalas, Dimitris; Zhao, Miaomiao; Yang, Jiangtao; Zhang, Binzhen; Chou, Xiujian; Liu, Jun; Xue, Chenyang; Zhang, Wendong

    2016-03-01

    A vectorial strain gauge method using a single sensing element is reported based on the double-sided polydimethylsiloxane (PDMS) Fraunhofer diffraction gratings structures. Using O2 plasma treatment steps, orthogonal wrinkled gratings were fabricated on both sides of a pre-strained PDMS film. Diffracted laser spots from this structure have been used to experimentally demonstrate, that any applied strain can be quantitatively characterized in both the x and y directions with an error of less than 0.6% and with a gauge factor of approximately 10. This simple and low cost technology which is completely different from the traditional vectorial strain gauge method, can be applied to surface vectorial strain measurement and multi-axis integrated mechanical sensors.

  9. Metal strain gauges on membranes at large deflection

    The output signal of metal strain gauges on membranes combined into a half bridge was investigated at deflections larger than three times their thickness. It was discovered that the signal reaches a maximum and then decreases with increasing deflection. When the pressure was applied in the opposite direction, the signal went through a minimum and then rose with increasing deflection. This can be interpreted as a shape transition of the membrane when deflected by more than its thickness. Besides this, the asymmetry of the signal with respect to drops in pressure in opposite directions of the membrane indicates that straining of the neutral fiber of the membrane shows a notable effect. The bridge output was also investigated with strain gauges on bi-stable membranes buckling due to compressive residual stress either up or down when no pressure difference was applied. (paper)

  10. The NASA Lewis Strain Gauge Laboratory: An update

    Hobart, H. F.

    1986-01-01

    Efforts continue in the development and evaluation of electrical resistance strain gauges of the thin film and small diameter wire type. Results obtained early in 1986 on some Chinese gauges and Kanthal A-1 gauges mounted on a Hastelloy-X substrate are presented. More recent efforts include: (1) the determination of the uncertainty in the ability to establish gauge factor, (2) the evaluation of sputtered gauges that were fabricated at Lewis, (3) an investigation of the efficacy of dual element temperature compensated gauges when using strain gauge alloys having large thermal coefficients of resistance, and (4) an evaluation of the practical methods of stabilizing gauges whose apparent strain is dependent on cooling rate (e.g., FeCrAl gauges).

  11. Dynamic and static strain gauge using superimposed fiber Bragg gratings

    This paper demonstrates a simple and fast interrogation method for the dynamic and/or static strain gauge using a reflection spectrum from two superimposed fiber Bragg gratings (FBGs). The superimposed FBGs are designed to decrease nonequidistant space of generated a sensing pulse train in a time domain during dynamic strain gauge. By combining centroid finding with smooth filtering methods, both the interrogation speed and accuracy are improved. A four times increase in the interrogation speed of dynamic strain, by generating a 2 kHz optical sensing pulse train from a 500 Hz scanning frequency, is demonstrated experimentally. The interrogation uncertainty and total harmonic distortion characterization of superimposed FBGs are tested and less than 4 pm standard deviation is obtained. (paper)

  12. Pencil Drawn Strain Gauges and Chemiresistors on Paper

    Cheng-Wei Lin; Zhibo Zhao; Jaemyung Kim; Jiaxing Huang

    2014-01-01

    Pencil traces drawn on print papers are shown to function as strain gauges and chemiresistors. Regular graphite/clay pencils can leave traces composed of percolated networks of fine graphite powders, which exhibit reversible resistance changes upon compressive or tensile deflections. Flexible toy pencils can leave traces that are essentially thin films of graphite/polymer composites, which show reversible changes in resistance upon exposure to volatile organic compounds due to absorption/deso...

  13. Embedded Strain Gauges for Condition Monitoring of Silicone Gaskets

    Timo Schotzko; Walter Lang

    2014-01-01

    A miniaturized strain gauge with a thickness of 5 µm is molded into a silicone O-ring. This is a first step toward embedding sensors in gaskets for structural health monitoring. The signal of the integrated sensor exhibits a linear correlation with the contact pressure of the O-ring. This affords the opportunity to monitor the gasket condition during installation. Thus, damages caused by faulty assembly can be detected instantly, and early failures, with their associated consequences, can be ...

  14. Magnetostriction strain measurement: heterodyne laser interferometry versus strain gauge technique

    Gorji Ghalamestani, Setareh; Vandevelde, Lieven; J.J. Dirckx, Joris; Melkebeek, Jan

    2013-01-01

    Deformation of the ferromagnetic material, known as magnetostriction, causes vibrations and noise of electrical machines and transformer cores. A setup by using heterodyne laser interferometers has been built to measure the magnetostriction strains as a function of the applied magnetic field. The measurement results on a sample of nonoriented electrical steel are presented in this work. These results are compared with those obtained by using a strain gauge setup. The laser measurements are l...

  15. Vectorial strain gauge method using single flexible orthogonal polydimethylsiloxane gratings

    Hao Guo; Jun Tang; Kun Qian; Dimitris Tsoukalas; Miaomiao Zhao; Jiangtao Yang; Binzhen Zhang; Xiujian Chou; Jun Liu; Chenyang Xue; Wendong Zhang

    2016-01-01

    A vectorial strain gauge method using a single sensing element is reported based on the double-sided polydimethylsiloxane (PDMS) Fraunhofer diffraction gratings structures. Using O2 plasma treatment steps, orthogonal wrinkled gratings were fabricated on both sides of a pre-strained PDMS film. Diffracted laser spots from this structure have been used to experimentally demonstrate, that any applied strain can be quantitatively characterized in both the x and y directions with an error of less t...

  16. Universal digital strain gauge measurement system of aeroelastic deformation development

    Pavlov Anton; Arefiev Alexander

    2016-01-01

    This article presents description of the universal digital strain gauge system developed to measure the static and dynamic aeroelastic deformations of elasticity-scale models during the tests in aerodynamic tube and during in-flight tests of an experimental air vehicles. The main requirements for such devices are small size and possibility of operation in a wide temperature range. The article considers the dependence of zero offset from temperature. Functional diagram block and logic diagram ...

  17. Two-Dimensional Laser-Speckle Surface-Strain Gauge

    Barranger, John P.; Lant, Christian

    1992-01-01

    Extension of Yamaguchi's laser-speckle surface-strain-gauge method yields data on two-dimensional surface strains in times as short as fractions of second. Laser beams probe rough spot on surface of specimen before and after processing. Changes in speckle pattern of laser light reflected from spot indicative of changes in surface strains during processing. Used to monitor strains and changes in strains induced by hot-forming and subsequent cooling of steel.

  18. Pd/Cr Strain Gauges For High Temperatures

    Lei, Jih-Fen

    1992-01-01

    Temperature-compensated Pd/Cr electrical-resistance strain gauges measure static strains in combustors, blades, and vanes of gas turbine engines. Made of alloy of 87 weight percent Pd and 13 weight percent Cr. Microstructure highly stable; undergoes no transformation of phase between ambient temperature and 1,000 degrees C. Gives highly repeatable readings with low drift at temperatures from ambient to 600 degrees C.

  19. Conical strain gauge probe for stress measurement (delopment)

    Staš, Lubomír; Knejzlík, Jaromír; Souček, Kamil; Rambouský, Zdeněk

    Athens : Heliotopos Conference, 2006 - (Agioutanstis, Z.; Komnitsas, K.), s. 523-528 ISBN 960-89228-1-X. [AMIREG2006/2./. Hania (GR), 25.09.2006-27.09.2006] R&D Projects: GA ČR GA105/06/1768; GA AV ČR IBS3086351 Institutional research plan: CEZ:AV0Z30860518 Keywords : strain gauge probe * stress measurement * conical probe Subject RIV: JQ - Machines ; Tools

  20. Strain gauge measurement uncertainties on hydraulic turbine runner blade

    Strains experimentally measured with strain gauges can differ from those evaluated using the Finite Element (FE) method. This difference is due mainly to the assumptions and uncertainties inherent to each method. To circumvent this difficulty, we developed a numerical method based on Monte Carlo simulations to evaluate measurement uncertainties produced by the behaviour of a unidirectional welded gauge, its position uncertainty and its integration effect. This numerical method uses the displacement fields of the studied part evaluated by an FE analysis. The paper presents a study case using in situ data measured on a hydraulic turbine runner. The FE analysis of the turbine runner blade was computed, and our numerical method used to evaluate uncertainties on strains measured at five locations with welded strain gauges. Then, measured strains and their uncertainty ranges are compared to the estimated strains. The uncertainty ranges obtained extended from 74 με to 165 με. Furthermore, the biases observed between the median of the uncertainty ranges and the FE strains varied from −36 to 36 με. Note that strain gauge measurement uncertainties depend mainly on displacement fields and gauge geometry.

  1. Embedded Strain Gauges for Condition Monitoring of Silicone Gaskets

    Timo Schotzko

    2014-07-01

    Full Text Available A miniaturized strain gauge with a thickness of 5 µm is molded into a silicone O-ring. This is a first step toward embedding sensors in gaskets for structural health monitoring. The signal of the integrated sensor exhibits a linear correlation with the contact pressure of the O-ring. This affords the opportunity to monitor the gasket condition during installation. Thus, damages caused by faulty assembly can be detected instantly, and early failures, with their associated consequences, can be prevented. Through the embedded strain gauge, the contact pressure applied to the gasket can be directly measured. Excessive pressure and incorrect positioning of the gasket can cause structural damage to the material of the gasket, which can lead to an early outage. A platinum strain gauge is fabricated on a thin polyimide layer and is contacted through gold connections. The measured resistance pressure response exhibits hysteresis for the first few strain cycles, followed by a linear behavior. The short-term impact of the embedded sensor on the stability of the gasket is investigated. Pull-tests with O-rings and test specimens have indicated that the integration of the miniaturized sensors has no negative impact on the stability in the short term.

  2. First International Symposium on Strain Gauge Balances. Pt. 1

    Tripp, John S. (Editor); Tcheng, Ping (Editor)

    1999-01-01

    The first International Symposium on Strain Gauge Balances was sponsored and held at NASA Langley Research Center during October 22-25, 1996. The symposium provided an open international forum for presentation, discussion, and exchange of technical information among wind tunnel test technique specialists and strain gauge balance designers. The Symposium also served to initiate organized professional activities among the participating and relevant international technical communities. Over 130 delegates from 15 countries were in attendance. The program opened with a panel discussion, followed by technical paper sessions, and guided tours of the National Transonic Facility (NTF) wind tunnel, a local commercial balance fabrication facility, and the LaRC balance calibration laboratory. The opening panel discussion addressed "Future Trends in Balance Development and Applications." Forty-six technical papers were presented in 11 technical sessions covering the following areas: calibration, automatic calibration, data reduction, facility reports, design, accuracy and uncertainty analysis, strain gauges, instrumentation, balance design, thermal effects, finite element analysis, applications, and special balances. At the conclusion of the Symposium, a steering committee representing most of the nations and several U.S. organizations attending the Symposium was established to initiate planning for a second international balance symposium, to be held in 1999 in the UK.

  3. First International Symposium on Strain Gauge Balances. Part 2

    Tripp, John S (Editor); Tcheng, Ping (Editor)

    1999-01-01

    The first International Symposium on Strain Gauge Balances was sponsored and held at NASA Langley Research Center during October 22-25, 1996. The symposium provided an open international forum for presentation, discussion, and exchange of technical information among wind tunnel test technique specialists and strain gauge balance designers. The Symposium also served to initiate organized professional activities among the participating and relevant international technical communities. Over 130 delegates from 15 countries were in attendance. The program opened with a panel discussion, followed by technical paper sessions, and guided tours of the National Transonic Facility (NTF) wind tunnel, a local commercial balance fabrication facility, and the LaRC balance calibration laboratory. The opening panel discussion addressed "Future Trends in Balance Development and Applications." Forty-six technical papers were presented in 11 technical sessions covering the following areas: calibration, automatic calibration, data reduction, facility reports, design, accuracy and uncertainty analysis, strain gauges, instrumentation, balance design, thermal effects, finite element analysis, applications, and special balances. At the conclusion of the Symposium, a steering committee representing most of the nations and several U.S. organizations attending the Symposium was established to initiate planning for a second international balance symposium, to be held in 1999 in the UK.

  4. Embedded strain gauges for condition monitoring of silicone gaskets.

    Schotzko, Timo; Lang, Walter

    2014-01-01

    A miniaturized strain gauge with a thickness of 5 µm is molded into a silicone O-ring. This is a first step toward embedding sensors in gaskets for structural health monitoring. The signal of the integrated sensor exhibits a linear correlation with the contact pressure of the O-ring. This affords the opportunity to monitor the gasket condition during installation. Thus, damages caused by faulty assembly can be detected instantly, and early failures, with their associated consequences, can be prevented. Through the embedded strain gauge, the contact pressure applied to the gasket can be directly measured. Excessive pressure and incorrect positioning of the gasket can cause structural damage to the material of the gasket, which can lead to an early outage. A platinum strain gauge is fabricated on a thin polyimide layer and is contacted through gold connections. The measured resistance pressure response exhibits hysteresis for the first few strain cycles, followed by a linear behavior. The short-term impact of the embedded sensor on the stability of the gasket is investigated. Pull-tests with O-rings and test specimens have indicated that the integration of the miniaturized sensors has no negative impact on the stability in the short term. PMID:25014099

  5. A Study on the Development and Characteristics of Strain Gauge using Sputter Machining

    The control of resistance of foil strain gauge is accomplished by means of etching technique. Thus, there is an irregularity in metal foil. In order to solve this problem, ion sputter machining method has been used to make strain gauge in this study and the characteristics of this strain gauge are investigated. As the result of this study, it was possible to make a flexible strain gauge which can be used to measure the stress. The strain gauge made by authors shows superior characteristics in creep, O point variance, hysteresis and nonlinearity by surrounding temperature

  6. Comparison between strain values of plates measured by ESPI technique and strain gauge method

    Comparison between strain values of plates measured by Electronic Speckle Pattern Interferometry(ESPI) method and strain gauge method is discussed. Unlike traditional method, such ax strain gauge and moire method, ESPI method requires no special surface preparations or attachments and can be measured in-plane displacement with non-contacting in real-time. In this study, specimens are loaded in parallel using tensile testing machine. In front of a specimen three strain gauges are bonded with 5 mm gap from edge of a specimen strain values are measured at each strain gauge position and compared. The results by ESPI method agree well with the result by strain gauge method.

  7. Fiber-Optic Strain Gauge With High Resolution And Update Rate

    Figueroa, Fernando; Mahajan, Ajay; Sayeh, Mohammad; Regez, Bradley

    2007-01-01

    An improved fiber-optic strain gauge is capable of measuring strains in the approximate range of 0 to 50 microstrains with a resolution of 0.1 microstrain. (To some extent, the resolution of the strain gauge can be tailored and may be extensible to 0.01 microstrain.) The total cost of the hardware components of this strain gauge is less than $100 at 2006 prices. In comparison with prior strain gauges capable of measurement of such low strains, this strain gauge is more accurate, more economical, and more robust, and it operates at a higher update rate. Strain gauges like this one are useful mainly for measuring small strains (including those associated with vibrations) in such structures as rocket test stands, buildings, oilrigs, bridges, and dams. The technology was inspired by the need to measure very small strains on structures supporting liquid oxygen tanks, as a way to measure accurately mass of liquid oxygen during rocket engine testing. This improved fiber-optic strain gauge was developed to overcome some of the deficiencies of both traditional foil strain gauges and prior fiber-optic strain gauges. Traditional foil strain gages do not have adequate signal-to-noise ratios at such small strains. Fiber-optic strain gauges have been shown to be potentially useful for measuring such small strains, but heretofore, the use of fiberoptic strain gauges has been inhibited, variously, by complexity, cost, or low update rate.

  8. Thick Film Temperature Compensating Circuit for Semiconductor Strain Gauges

    Mitsuo Ai; Hiromi Tosaki; Akira Ikegami; Hideo Arima; Yoshitaka Matsuoka; Tsutomu Okayama

    1981-01-01

    Thick film circuits were developed for temperature compensating of semiconductor strain gauges and for connecting the gauges to amplifiers in electronic pressure and differential pressure transmitters. In each circuit, ten Au pads for Al wire bonding and thirteen Ag/Pd pads for soldering must be fabricated on a small substrate. The results of the research are shown below.(1) The resistance values and the thermistor constants required for the thermistors are 0.9 ± 0.09 kilo-ohm and 2500 ± 40 K...

  9. Dielectric-waveguide strain gauge: a theoretical study

    We present a theoretical analysis of the strain dependence of bend loss from a multimode slab dielectric waveguide formed in the shape of an arc of a circle. This dependence suggests its use as a strain gauge. We calculate the strain sensitivity of this gauge as a function of the core-cladding index difference, bend radius, and arc angle. The method that we use is a geometrical-optics analysis modified to account for the curvature of the boundary between the core and the cladding

  10. An Intelligent Strain Gauge with Debond Detection and Temperature Compensation

    Jensen, Scott L.

    2012-01-01

    The harsh rocket propulsion test environment will expose any inadequacies associated with preexisting instrumentation technologies, and the criticality for collecting reliable test data justifies investigating any encountered data anomalies. Novel concepts for improved systems are often conceived during the high scrutiny investigations by individuals with an in-depth knowledge from maintaining critical test operations. The Intelligent Strain Gauge concept was conceived while performing these kinds of activities. However, the novel concepts are often unexplored even if it has the potential for advancing the current state of the art. Maturing these kinds of concepts is often considered to be a tangential development or a research project which are both normally abandoned within the propulsion-oriented environment. It is also difficult to justify these kinds of projects as a facility enhancement because facility developments are only accepted for mature and proven technologies. Fortunately, the CIF program has provided an avenue for bringing the Intelligent Strain Gauge to fruition. Two types of fully functional smart strain gauges capable of performing reliable and sensitive debond detection have been successfully produced. Ordinary gauges are designed to provide test article data and they lack the ability to supply information concerning the gauge itself. A gauge is considered to be a smart gauge when it provides supplementary data relating other relevant attributes for performing diagnostic function or producing enhanced data. The developed strain gauges provide supplementary signals by measuring strain and temperature through embedded Karma and nickel chromium (NiCr) alloy elements. Intelligently interpreting the supplementary data into valuable information can be performed manually, however, integrating this functionality into an automatic system is considered to be an intelligent gauge. This was achieved while maintaining a very low mass. The low mass enables

  11. Analysis of thermal output of high temperature strain gauge by different measurement methods

    Background: Thermal output of high temperature strain gauges can be measured by different methods. Purpose: This paper is to discover measurement methods' effects on thermal output of high temperature strain gauge and to suggest a method of clamping instead of welding for fixture of high temperature strain gauge for thermal output measurement. Methods: By analysis of impacting factors of thermal output, thermal outputs were explored for mismatching thermal expansion coefficients between material of components to be tested and that of strain gauge base. Thermal outputs of all kinds by different fixture methods were obtained and compared for hanging, clamping and spot welding, respectively. Results: Thermal output obtained by way of hanging strain gauge can be used in case of installation on material of the same thermal expansion coefficient as the strain gauge base. And this hanging measurement method provides access to thermal output that strain gauge undergoes different temperature changing ratio from that one of provision offered by strain gauge fabrication factory. Thermal output obtained by way of clamping measurement method can substitute for the one obtained by spot welding. This clamping measurement method can not only realize the effect of spot welding, reducing calibration cost due to spot welding of strain gauges, but also realize the aim of calibration of strain gauges one by one with the strain gauges be intact after calibration. Differences between thermal outputs by two measurement ways of both hanging and clamping explain that large divergence can be made when thermal expansion coefficients between the material of strain gauge base and the one of the component to be installed on. Conclusions: Thermal output can be measured among all methods by fixture of clamping instead of welding, with an advantage of realizing strain gauge calibration one by one and also with a high precision. (authors)

  12. Load-application devices: a comparative strain gauge analysis.

    Nishioka, Renato Sussumu; de Vasconcellos, Luis Gustavo Oliveira; Jóias, Renata Pilli; Rode, Sigmar de Mello

    2015-01-01

    In view of the low loading values commonly employed in dentistry, a load-application device (LAD) was developed as option to the universal testing machine (UTM), using strain gauge analysis. The aim of this study was to develop a load-application device (LAD) and compare the LAD with the UTM apparatus under axial and non-axial loads. An external hexagonal implant was inserted into a polyurethane block and one EsthetiCone abutment was connected to the implant. A plastic prosthetic cylinder was screwed onto the abutment and a conical pattern crown was fabricated using acrylic resin. An impression was made and ten identical standard acrylic resin patterns were obtained from the crown impression, which were cast in nickel-chromium alloy (n=10). Four strain gauges were bonded diametrically around the implant. The specimens were subjected to central (C) and lateral (L) axial loads of 30 kgf, on both devices: G1: LAD/C; G2: LAD/L; G3: UTM/C; G4: UTM/L. The data (με) were statistically analyzed by repeated measures ANOVA and Tukey's test (p<0.05). No statistically significant difference was found between the UTM and LAD devices, regardless of the type of load. It was concluded that the LAD is a reliable alternative, which induces microstrains to implants similar to those obtained with the UTM. PMID:26200149

  13. Electron transport in gold colloidal nanoparticle-based strain gauges

    A systematic approach for understanding the electron transport mechanisms in resistive strain gauges based on assemblies of gold colloidal nanoparticles (NPs) protected by organic ligands is described. The strain gauges were fabricated from parallel micrometer wide wires made of 14 nm gold (Au) colloidal NPs on polyethylene terephthalate substrates, elaborated by convective self-assembly. Electron transport in such devices occurs by inter-particle electron tunneling through the tunnel barrier imposed by the organic ligands protecting the NPs. This tunnel barrier was varied by changing the nature of organic ligands coating the nanoparticles: citrate (CIT), phosphines (BSPP, TDSP) and thiols (MPA, MUDA). Electro-mechanical tests indicate that only the gold NPs protected by phosphine and thiol ligands yield high gauge sensitivity. Temperature-dependent resistance measurements are explained using the ‘regular island array model’ that extracts transport parameters, i.e., the tunneling decay constant β and the Coulomb charging energy EC. This reveals that the Au-CIT nanoparticle assemblies exhibit a behavior characteristic of a strong-coupling regime, whereas those of Au-BSPP, Au-TDSP, Au-MPA and Au-MUDA nanoparticles manifest a weak-coupling regime. A comparison of the parameters extracted from the two methods indicates that the most sensitive gauges in the weak-coupling regime feature the highest β. Moreover, the EC values of these 14 nm NPs cannot be neglected in determining the β values. (paper)

  14. Monopiece strain gauge sting mounted wind tunnel balance

    Faucher, Gilles; Paradis, Marc-Andre; Girard, Bertrand

    1992-12-01

    A balance is disclosed for an apparatus for measuring the various aerodynamic coefficients of flight vehicles by testing scale models of these vehicles in a wind tunnel. The balance of the invention measures the following parameters: axial, normal, and side force; and pitching, yawing, and rolling moments. The balance is based on a monopiece center core where sensing components have a roll or primary frame as well as being reference supports to strain gauges. The dual function of the primary frame means that forces and moments, when applied to the balance, will generate interferences in several other components. Because of the center core configuration, it is possible to calibrate, calculate, and deduct with a very high precision the interferences of each component over the other. Except for the axial force sensing components, all forces and moments are sensed by two groups of crossed webs, one cross web at each end of the center core. The axial force sensing components are made of two tensioning rings, one at each end of the center core. The configuration of the balance is of the rigid-frame type, in order to make use of semiconductor strain gauges which are very precise. The resulting balance is more precise than any known balance of its size and can resist starting and stopping overloads which occur at the beginning and end of a test.

  15. A microfabricated strain gauge array on polymer substrate for tactile neuroprostheses in rats

    Beygi, M.; Mutlu, S.; Güçlü, B.

    2016-08-01

    In this study, we present the design, microfabrication and characterization of a tactile sensor system which can be used for sensory neuroprostheses in rats. The sensor system consists of an array of 2  ×  7 cells, each of which has a series combination of four strain gauges. Each group of four strain gauges is placed around a square membrane with a size of 2.5  ×  2.5 mm2. Unlike most common tactile sensors based on silicon substrates, we used 3D-printed polylactic acid as a substrate, because it is not brittle, and under local extremes, it would prevent the catastrophic failure of all cells. The strain gauges were fabricated by depositing and patterning a 50 nm thick aluminum (Al) film on a polyimide sheet with a thickness of 0.125 mm. Polydimethylsiloxane (PDMS) elastomer was bonded on the top surface of the PI membrane. The PDMS layer was prepared in two different thicknesses, 1.2 and 1.7 mm, to investigate its effect on the static response of the sensor. The sensitivity and the maximum allowable force, corresponding to the maximum deformation of 0.9 mm at the center of each cell, changed based on the thickness of the PDMS layer. Sensor cells operated linearly up to 3 N with an average sensitivity of 200 mΩ N‑1 (0.7 Ω mm‑1) for 1.2 mm thick PDMS. These values changed to 4 N and 70 mΩ N‑1 (0.3 Ω mm‑1), respectively, for 1.7 mm thick PDMS. The nonlinearity was less than 3%. The cells had low cross-talk (~5 mΩ N‑1 and 0.02 Ω mm‑1) relative to the average sensitivity. Additionally, the dynamic response of the sensor was characterized at several frequencies by using a vibrotactile stimulation system previously designed for psychophysics experiments. The sensor was also tested inside the rat conditioning chamber to demonstrate the relevant signals in a tactile neuroprosthesis.

  16. Protective Coats For High-Temperature Strain Gauges

    Lei, Jih-Fen

    1993-01-01

    Addition of some rare-earth oxides to prior alumina (only) coating material increases maximum service temperature of palladium/chromium-wire strain gauges. Pd/Cr wires used at temperatures up to 800 degrees C without excessive drift in electrical resistance. Oxides used: zirconia (ZrO2), yttria (Y2O3), ceria (CeO2), and hafnia (HfO2). Addition of one of these oxides to decrease oxidation of wire at high temperature. Protection against oxidation increases with concentration of rare-earth oxide. Addition of ZrO2 at 4 to 6 weight percent or Y2O3 at 1 weight percent results in smallest drift in electrical resistance.

  17. Strain gauge ambiguity sensor for segmented mirror active optical system

    Wyman, C. L.; Howe, T. L. (Inventor)

    1974-01-01

    A system is described to measure alignment between interfacing edges of mirror segments positioned to form a segmented mirror surface. It serves as a gauge having a bending beam with four piezoresistive elements coupled across the interfaces of the edges of adjacent mirror segments. The bending beam has a first position corresponding to alignment of the edges of adjacent mirror segments, and it is bendable from the first position in a direction and to a degree dependent upon the relative misalignment between the edges of adjacent mirror segments to correspondingly vary the resistance of the strain guage. A source of power and an amplifier are connected in circuit with the strain gauge whereby the output of the amplifier varies according to the misalignment of the edges of adjacent mirror segments.

  18. A nanocrystal strain gauge for luminescence detection of mechanical forces

    Choi, Charina; Koski, Kristie; Olson, Andrew; Alivisatos, Paul

    2010-07-26

    Local microscale stresses play a crucial role in inhomogeneous mechanical processes from cell motility to material failure. However, it remains difficult to spatially resolve stress at these small length scales. While contact-probe and non-contact based techniques have been used to quantify local mechanical behavior in specific systems with high stiffness or stress and spatial resolution, these methods cannot be used to study a majority of micromechanical systems due to spectroscopic and geometrical constraints. We present here the design and implementation of a luminescent nanocrystal strain gauge, the CdSe/CdS core/shell tetrapod. The tetrapod can be incorporated into many materials, yielding a local stress measurement through optical fluorescence spectroscopy of the electronically confined CdSe core states. The stress response of the tetrapod is calibrated and utilized to study mechanical behavior in single polymer fibers. We expect that tetrapods can be used to investigate local stresses in many other mechanical systems.

  19. DEVELOPMENT FOR HIGH PRECISION SIX COMPONENT STRAIN GAUGE BALANCE

    ZHANGZhao-ming; HANBu-zhang

    2004-01-01

    The measurement accuracy of a wind tunnel balance is the key factor to improve the measurement accuracy for a test model in the wind tunnel. In order to improve the measurement accuracy of the wind tunnel balance, a great deal of investigation is carried out in China. This paper summarizes a program to improve the measurement accuracy of wind tunnel balances. In the program, the investigation is carried out in three aspects (1) designing a drag component of the balance in low interactions (2) choosing high quality foil strain gauges with temperature self-compensation (3) choosing the excellent gauges and mounting them meticulously. As an example, these research achievements are applied in a φ18 six component balance. The measurement accuracy of a GB-04 standard model in a transonic wind tunnel with the φ18 six component balance comes up to the advanced world standard.

  20. Employing high temperature strain gauges up to 1000 C. Hochtemperatur-Dehnungsmessstreifen bis 1000 C einsetzen

    Gaus, R. (IABG, Ottobrunn (Germany)); Dienz, M. (IABG, Ottobrunn (Germany)); Baer, K.K.O. (IABG, Ottobrunn (Germany))

    1994-01-01

    The application of high temperature strain gauges for strain measuring up to 1000 C has been developed and qualified. As basis, free filament strain gauges have been used. Different high temperature bonds and different supply lines were tested. Together with optimized data acquisition options an accuracy of about 0.002 [Omega] ([ne]10 microstrain) has been attained. (orig.)

  1. Мathematical model of new strain gauge of linear deformation

    Кубрак, Юрій Олександрович; Грабар, Іван Григорович

    2012-01-01

    New strain gauge of linear deformation (SGLD) with the basis of percolation sensitive element of “conductive-dielectric” type is offered. Theoretical principles of the strain gauge behavior are given. Dependence of electrical resistance of SGLD from the substrate type, from substrate deformation and from the electroconductive component type is obtained

  2. The behaviour of weldable strain gauges under nuclear reactor core conditions

    Highlights: • Electrical resistance strain gauges can be used in nuclear reactor environments. • Several in-reactor experiments featuring the use of strain gauges are described. • Static and dynamic strain can be measured under the very hostile conditions of nuclear reactor cores. • Irradiation effects can be corrected if they are well understood and precisely quantified. -- Abstract: Electrical resistance strain gauges are a very useful tool to measure mechanical parameters such as deformation, stress, dynamic strain, vibration, etc. This paper presents our experience with strain gauges in nuclear reactor environments. The nature of nuclear applications and the desirable characteristics of nuclear strain gauges are discussed. Several in-reactor experiments featuring the use of strain gauges are described. The behaviour of weldable strain gauges under intense nuclear radiation is discussed. Experimental results and techniques for the successful applications of strain gauges in nuclear environments are presented. It is concluded that weldable stain gauges can be used successfully under the very hostile conditions of nuclear reactor cores if appropriate procedures are followed

  3. Deformable trailing edge flaps for modern megawatt wind turbine controllers using strain gauge sensors

    Andersen, Peter Bjørn; Henriksen, Lars Christian; Gaunaa, Mac;

    2010-01-01

    enabling the trailing edge to move independently and quickly along the spanwise position of the blade, local small flutuations in the aerodynamic forces can be alleviated by deformation of the airfoil flap. Strain gauges are used as input for the flap controller, and the effect of placing strain gauges at...

  4. Correction of Gauge Factor for Strain Gauges Used in Polymer Composite Testing

    Zike, Sanita; Mikkelsen, Lars Pilgaard

    2014-01-01

    Strain gauges are used together with the corresponding gauge factor to relate the relative electrical resistance change of the strain gauge with the strain of the underlying material. The gauge factor is found from a calibration on a stiff material - steel. Nevertheless, the gauge factor depends ...... ranging from 1 GPa to 200 GPa....

  5. NiCr thin film strain gauges fabricated on glass substrates

    Danisman, Murat [Yildiz Technical Univ., Istanbul (Turkey). Metallurgical and Engineering Dept.; Cansever, Nurhan [Gedik Univ., Istanbul (Turkey). Electronic Engineering Dept.

    2013-10-01

    In order to investigate the strain gauge characteristics of NiCr thin films, 500 nm NiCr (80 wt.-% and 20 wt.-%, respectively) thin films were deposited on glass substrates by DC magnetron sputtering. After deposition, NiCr thin films were characterized by using X-Ray diffraction analysis, scanning electron microscope and four-point probe techniques inview of crystallization, phases, film structure and electrical resistivity. After characterization, NiCr thin films were shaped into strain gauges by photo lithography and wet etching techniques. Strain gauges were tested with different loads, and strain values were calculated by comparing the results with commercial NiCr strain gauges with the same surface area. Resistivity change vs. strain was plotted, and the gauge factor of fabricated thin film strain gauges was evaluated as 1.23. (orig.)

  6. A high-resolution strain-gauge nanolaser

    Choi, Jae-Hyuck; No, You-Shin; So, Jae-Pil; Lee, Jung Min; Kim, Kyoung-Ho; Hwang, Min-Soo; Kwon, Soon-Hong; Park, Hong-Gyu

    2016-05-01

    Interest in mechanical compliance has been motivated by the development of flexible electronics and mechanosensors. In particular, studies and characterization of structural deformation at the fundamental scale can offer opportunities to improve the device sensitivity and spatiotemporal response; however, the development of precise measurement tools with the appropriate resolution remains a challenge. Here we report a flexible and stretchable photonic crystal nanolaser whose spectral and modal behaviours are sensitive to nanoscale structural alterations. Reversible spectral tuning of ~26 nm in lasing wavelength, with a sub-nanometre resolution of less than ~0.6 nm, is demonstrated in response to applied strain ranging from -10 to 12%. Instantaneous visualization of the sign of the strain is also characterized by exploring the structural and corresponding modal symmetry. Furthermore, our high-resolution strain-gauge nanolaser functions as a stable and deterministic strain-based pH sensor in an opto-fluidic system, which may be useful for further analysis of chemical/biological systems.

  7. Metal ion implantation in inert polymers for strain gauge applications

    Metal ion implantation in inert polymers may produce ultra-thin conducting films below the polymer surface. These subsurface films are promising structures for strain gauge applications. To this purpose, polycarbonate substrates were irradiated at room temperature with low-energy metal ions (Cu+ and Ni+) and with fluences in the range between 1 x 1016 and 1 x 1017 ions/cm2, in order to promote the precipitation of dispersed metal nanoparticles or the formation of a continuous thin film. The nanoparticle morphology and the microstructural properties of polymer nanocomposites were investigated by glancing-incidence X-ray diffraction and transmission electron microscopy (TEM) measurements. At lower fluences (16 ions/cm2) a spontaneous precipitation of spherical-shaped metal nanoparticles occurred below the polymer top-surface (∼50 nm), whereas at higher fluences the aggregation of metal nanoparticles produced the formation of a continuous polycrystalline nanofilm. Furthermore, a characteristic surface plasmon resonance peak was observed for nanocomposites produced at lower ion fluences, due to the presence of Cu nanoparticles. A reduced electrical resistance of the near-surface metal-polymer nanocomposite was measured. The variation of electrical conductivity as a function of the applied surface load was measured: we found a linear relationship and a very small hysteresis.

  8. Positive/negative magnetostrictive GMR trilayer systems as strain gauges

    Recently, highly sensitive strain gauges were developed, which are based on tunnel magnetoresistance (TMR) or giant magnetoresistance (GMR) effects combined with the inverse magnetostriction. GMR and TMR structures generally possess a symmetrical characteristic, which reflects the switching fields of the soft and hard layers, respectively. This characteristic can be changed by a stress field if the soft layer is replaced by a suitable magnetostrictive layer leading to a stress-induced rotation of the magnetostrictive layer with respect to the reference layer. Alternatively, both magnetic layers can be soft magnetic, one being positive and the other negative magnetostrictive. In this case, a stress applied on the stack leads to a reverse rotation of both layers due to the different sign in magnetostriction. This new approach is especially attractive since no reference layer is required which allows multilayering for GMR effect enhancement. This paper presents the stress biased characteristics of (FeCo/Cu/Ni) GMR trilayers in which the positive magnetostrictive FeCo and the negative magnetostrictive Ni replace the sensing and reference layer of a conventional GMR stack. The results can be interpreted by a simple model taking into account the magnetization direction of the individual layers and their response to mechanical strain in the range of 0.1-1%o

  9. A high-resolution strain-gauge nanolaser.

    Choi, Jae-Hyuck; No, You-Shin; So, Jae-Pil; Lee, Jung Min; Kim, Kyoung-Ho; Hwang, Min-Soo; Kwon, Soon-Hong; Park, Hong-Gyu

    2016-01-01

    Interest in mechanical compliance has been motivated by the development of flexible electronics and mechanosensors. In particular, studies and characterization of structural deformation at the fundamental scale can offer opportunities to improve the device sensitivity and spatiotemporal response; however, the development of precise measurement tools with the appropriate resolution remains a challenge. Here we report a flexible and stretchable photonic crystal nanolaser whose spectral and modal behaviours are sensitive to nanoscale structural alterations. Reversible spectral tuning of ∼26 nm in lasing wavelength, with a sub-nanometre resolution of less than ∼0.6 nm, is demonstrated in response to applied strain ranging from -10 to 12%. Instantaneous visualization of the sign of the strain is also characterized by exploring the structural and corresponding modal symmetry. Furthermore, our high-resolution strain-gauge nanolaser functions as a stable and deterministic strain-based pH sensor in an opto-fluidic system, which may be useful for further analysis of chemical/biological systems. PMID:27175544

  10. Cold pressor test using strain-gauge plethysmography.

    Feliciani, Giacomo; Peron, Cristiano; La Rocca, Augusto; Scuppa, Maria Francesca; Malavolta, Andrea; Bianchini, David; Corazza, Ivan; Zannoli, Romano

    2016-09-01

    This laboratory activity is designed to teach students how to measure forearm muscle blood flow (FBF) to describe the mechanisms of peripheral blood flow thermal regulation in healthy subjects. The cold pressor test (CPT) is the clinical procedure used in the experiment to induce arterial vasoconstriction. Strain-gauge plethysmography is applied on the patient's forearm to noninvasive monitor vasoconstriction effects on local blood perfusion and physiological parameters such as blood pressure (BP) and heart rate (HR). Patients with an altered peripheral vascular resistance (e.g., in hypertension) have different responses to the CPT from healthy subjects. To date, experimental evidence remains unexplained, as we do not know if the BP and HR increase is caused by a decrease in flow rate or an increase in peripheral vascular resistance during the test. To clarify this situation, we have to quantify the parameter we assume is being conditioned by the regulatory physiological intervention, i.e., peripheral vascular resistance. Peripheral vascular resistance quantification can be calculated as the ratio between muscle flow and mean arterial pressure. Students will learn how to apply the instrumental procedure to collect and analyze data before, during, and after the CPT and to describe the physiological responses of the peripheral vascular system to external stressors. They will also learn how to distinguish healthy from pathological responses on the basis of how sympathetic nervous system reactions influence the biomechanics of peripheral vessels. PMID:27503902

  11. Comparison between CMM2 & ISO9001

    2001-01-01

    The Capability Maturity Model(CMM) and ISO9001 are probably thetwo be st known and most widely used models for software organization quality assurance and improvement. As they both continue to evolve, each has a series of versions which own new aspects. This paper discusses the similarities and differences be tween the two models, based on the CMM version 2.0 c and the 1997 release of ISO 9001, examines 20 clauses in ISO9001 and maps them to practices in the latest CMM. In the end, their implementations in China are presented

  12. The use of intraluminal strain gauges for recording ambulant small bowel motility.

    Gill, R C; Kellow, J E; Browning, C; Wingate, D L

    1990-04-01

    Perfused-tube manometry has hitherto been the standard technique for recording intraluminal intestinal pressure in humans, but it is unsuitable for ambulant use. The aim of our study was to evaluate the ability of resistive strain gauge transducers attached to a fine catheter to detect pressure change. Simultaneous strain gauge and perfused-tube manometry was performed on six fasting subjects; in four, strain gauge activation was continuous and in two, the transducers were activated in a pulsed mode with data encoded as a pulse train with an approximate frequency of 20 Hz. Eight thousand eight hundred eighty-eight pressure waves were recorded by strain gauge, of which 96% were detected by perfused-tube manometry. There was good agreement in both phases II and III of the migrating motor complex. The amplitude of pressure waves recorded by strain gauge was slightly but significantly greater. A proportion (14-17%) of pressure waves recorded by strain gauge were bifid; this was not seen with the perfused tube. These differences are best explained by the greater sensitivity and more rapid rise time of the strain gauges. There was no loss of fidelity in the pulse-interval recording mode. A seventh subject underwent a continuous 72-h recording with the strain gauge catheter attached to a battery-operated encoder and magnetic tape cassette recorder and was freely ambulant during this period. The procedure was well tolerated and motility patterns could be clearly identified. We conclude that intraluminal strain gauge catheters are suitable for prolonged use in ambulant subjects and produce data that are closely comparable to the data acquired from perfused-tube manometry under laboratory conditions. PMID:2333973

  13. From measurements errors to a new strain gauge design for composite materials

    Mikkelsen, Lars Pilgaard; Salviato, Marco; Gili, Jacopo

    2015-01-01

    Significant over-prediction of the material stiffness in the order of 1-10% for polymer based composites has been experimentally observed and numerical determined when using strain gauges for strain measurements instead of non-contact methods such as digital image correlation or less stiff methods...... such as clip-on extensometers. In the present work, this has been quantified through a numerical study for three different strain gauges. In addition, a significant effect of a thin polymer coating or biaxial layer in the erroneous using strain gauges has been observed. An erroneous which can be...

  14. Fabrication of a Low Density Carbon Fiber Foam and Its Characterization as a Strain Gauge

    Claudia C. Luhrs

    2014-05-01

    Full Text Available Samples of carbon nano-fiber foam (CFF, essentially a 3D solid mat of intertwined nanofibers of pure carbon, were grown using the Constrained Formation of Fibrous Nanostructures (CoFFiN process in a steel mold at 550 °C from a palladium particle catalysts exposed to fuel rich mixtures of ethylene and oxygen. The resulting material was studied using Scanning Electron Microscopy (SEM, Energy Dispersive Spectroscopy (EDX, Surface area analysis (BET, and Thermogravimetric Analysis (TGA. Transient and dynamic mechanical tests clearly demonstrated that the material is viscoelastic. Concomitant mechanical and electrical testing of samples revealed the material to have electrical properties appropriate for application as the sensing element of a strain gauge. The sample resistance versus strain values stabilize after a few compression cycles to show a perfectly linear relationship. Study of microstructure, mechanical and electrical properties of the low density samples confirm the uniqueness of the material: It is formed entirely of independent fibers of diverse diameters that interlock forming a tridimensional body that can be grown into different shapes and sizes at moderate temperatures. It regains its shape after loads are removed, is light weight, presents viscoelastic behavior, thermal stability up to 550 °C, hydrophobicity, and is electrically conductive.

  15. Doppler ultrasound compared with strain gauge for measurement of systolic ankle blood pressure

    Joensen, Jette Bang; Juul, Søren; Abrahamsen, Jimmi;

    2012-01-01

    This study assesses measurement variation in the measurement of ankle systolic blood pressure (ABP) when measured with Doppler ultrasound and with the strain gauge method. Ninety-seven patients were included. ABP was measured with Doppler ultrasound and with the strain gauge method. The methods...... were compared graphically by scatterplots and analyzed by paired t test, analysis of variance, and Pitman's paired variance ratio test. ABP was measured by strain gauge in all extremities, whereas no Doppler signal was obtainable in 7 limbs (4%). There was no systematic difference in measurements...... between the means of the two measurements. However, a substantial difference of more than 25 mm Hg was found in 15% of limbs and more than 20 mm Hg in 20%. In the majority of patients, measurements of ABP by Doppler ultrasound and the strain gauge method give similar results, but for a minority the...

  16. An Intelligent Strain Gauge with Debond Detection and Temperature Compensation Project

    National Aeronautics and Space Administration — To improve instruments functionality in a harsh rocket propulsion test environment, this project developed an intelligent strain gauge.  The initial design for...

  17. Nanoparticle monolayer-based flexible strain gauge with ultrafast dynamic response for acoustic vibration detection

    Lizhi Yi[1; Weihong Jiao[1; Ke Wu[1; Lihua Qian[1; Xunxing Yu[2; Qi Xia[2; Kuanmin Mao[2; Songliu Yuan[1; Shuai Wang[3; Yingtao Jiang[4

    2015-01-01

    The relatively poor dynamic response of current flexible strain gauges has prevented their wide adoption in portable electronics. In this work, we present a greatly improved flexible strain gauge, where one strip of Au nanoparticle (NP) monolayer assembled on a polyethylene terephthalate film is utilized as the active unit. The proposed flexible gauge is capable of responding to applied stimuli without detectable hysteresis via electron tunneling between adjacent nanoparticles within the Au NP monolayer. Based on experimental quantification of the time and frequency domain dependence of the electrical resistance of the proposed strain gauge, acoustic vibrations in the frequency range of 1 to 20,000 Hz could be reliably detected. In addition to being used to measure musical tone, audible speech, and creature vocalization, as demonstrated in this study, the ultrafast dynamic response of this flexible strain gauge can be used in a wide range of applications, including miniaturized vibratory sensors, safe entrance guard management systems, and ultrasensitive pressure sensors.

  18. Design and Analysis of a Compact Precision Positioning Platform Integrating Strain Gauges and the Piezoactuator

    Shunguang Wan; Zhichao Ma; Chengli Shi; Zunqiang Fan; Zhaojun Yang; Hongwei Zhao; Hu Huang

    2012-01-01

    Miniaturization precision positioning platforms are needed for in situ nanomechanical test applications. This paper proposes a compact precision positioning platform integrating strain gauges and the piezoactuator. Effects of geometric parameters of two parallel plates on Von Mises stress distribution as well as static and dynamic characteristics of the platform were studied by the finite element method. Results of the calibration experiment indicate that the strain gauge...

  19. From measurements errors to a new strain gauge design for composite materials

    Mikkelsen, Lars Pilgaard; Salviato, Marco; Gili, Jacopo

    2015-01-01

    Significant over-prediction of the material stiffness in the order of 1-10% for polymer based composites has been experimentally observed and numerical determined when using strain gauges for strain measurements instead of non-contact methods such as digital image correlation or less stiff methods such as clip-on extensometers. In the present work, this has been quantified through a numerical study for three different strain gauges. In addition, a significant effect of a thin polymer coating ...

  20. Structural and geotechnical interpretation of strain gauge data from laterally loaded reinforced concrete piles

    Biocchi, Nicola

    2011-01-01

    Four instrumented sites, with a total of 14 instrumented piles, have been analysed to understand the structural behaviour of the piles and the geotechnical behaviour of the stabilised slopes. Vibrating wire strain gauges are used for the calculation of the bending moment applied to the piles, while inclinometers are used to measure the displacements. A review of the instrumentation has been carried out and a methodology for processin and analysing strain gauges data has been developed. Concre...

  1. Flexible gastrointestinal motility pressure sensors based on aluminum thin-film strain-gauge arrays

    Silva, Luís Rebelo; Sousa, Paulo J.; L.M. Gonçalves; Minas, Graça

    2015-01-01

    This paper reports on an innovative approach to measuring intraluminal pressure in the upper gastrointestinal (GI) tract, especially monitoring GI motility and peristaltic movements. The proposed approach relies on thin-film aluminum strain gauges deposited on top of a Kapton membrane, which in turn lies on top of an SU-8 diaphragm-like structure. This structure enables the Kapton membrane to bend when pressure is applied, thereby affecting the strain gauges and effectively cha...

  2. Gauge Factor and Stretchability of Silicon-on-Polymer Strain Gauges

    Nanshu Lu; Shixuan Yang

    2013-01-01

    Strain gauges are widely applied to measure mechanical deformation of structures and specimens. While metallic foil gauges usually have a gauge factor slightly over 2, single crystalline silicon demonstrates intrinsic gauge factors as high as 200. Although silicon is an intrinsically stiff and brittle material, flexible and even stretchable strain gauges have been achieved by integrating thin silicon strips on soft and deformable polymer substrates. To achieve a fundamental understanding of t...

  3. Manufacturing and characterization of printed strain gauges based on carbon nanotubes

    Arreba Garcia-Abad, Andrea

    2010-01-01

    Carbon nanotubes (CNTs), established in nanoscale range, are one of the most studied materials since their discovery, in Japan by S. Iijima in 1991. Due to their excellent electrical, mechanical and thermal properties, it is predicted that CNTs can be used in a wide field of technological applications. The aim of this thesis is to produce a CNT strain gauge due to this material offers higher sensitivity than metallic strain gauges, between other advantages. When manufacturing a CNT strain gau...

  4. A COMPARISON OF METHODS USING STRAIN GAUGES TO MONITOR PHYSIOLOGICAL MOVEMENTS ON A HOSPITAL BED

    Vladimír Socha; Patrik Kutílek; Pavel Smrčka; Luboš Socha

    2014-01-01

    Two methods which are suitable to monitor the small movements of the patient in a horizontal position on the bed are compared. The methods use sensors based on strain gauge bridges configured to measure the torsion deformation and sensors based on strain gauge bridges configured to measure the bending deformation of two two-arm brackets. Both methods provide information about the patient's physiological movements. The methods were tested and compared in order to decide which methods may be mo...

  5. Fiber Optic Rosette Strain Gauge Development and Application on a Large-Scale Composite Structure

    Moore, Jason P.; Przekop, Adam; Juarez, Peter D.; Roth, Mark C.

    2015-01-01

    A detailed description of the construction, application, and measurement of 196 FO rosette strain gauges that measured multi-axis strain across the outside upper surface of the forward bulkhead component of a multibay composite fuselage test article is presented. A background of the FO strain gauge and the FO measurement system as utilized in this application is given and results for the higher load cases of the testing sequence are shown.

  6. Development of the invar36 thin film strain gauge sensor for strain measurement

    This paper presents development of invar36 thin film strain gauges of various thicknesses ranging from 100 to 1400 Å for strain measurement. The strain gauges are deposited on microslides using the dc magnetron sputtering technique. Resistivity, temperature coefficient of resistance (TCR) and gauge factors of all gauges are measured and compared with each other. TCR is estimated by systematic annealing of gauges in vacuum and found as low as 190 ppm °C−1. A four-point bending setup is designed and fabricated to measure the gauge factors of all gauges. The gauge factor of relatively thinner strain gauge is found as high as 4.5 and for strain gauges with thickness greater than 500 Å gauge factor is found less than 2.5. The variations of gauge resistance with applied strain are studied in terms of linearity, hysteresis and repeatability. The developed strain gauges are connected in a full-bridge configuration and the output response to the applied strain is studied at different excitation voltages. (paper)

  7. AFM-CMM integrated instrument user manual

    Marinello, Francesco; Bariani, Paolo

    This manual gives general important guidelines for a proper use of the integrated AFM-CMM instrument. More information can be collected reading: • N. Kofod Ph.D thesis [1]; • P. Bariani Ph.D thesis [2]; • Dualscope DME 95-200 operation manuals [3]; • SPIP help [4] • Stitching software user manual...

  8. Serial strain gauge measurement of bone healing in hoffmann® external fixation.

    Nishimura, N

    1984-04-01

    In order to better assess callus strength for postoperative management of Hoffmann external fixation patients, the author attempted to estimate the amount of strain when bending or compressing the fracture site with a strain gauge glued to the middle of a connecting rod. Calculations in a computer architectural model of a plane beam structure show that the amount of strain on a connecting rod would decrease hyperbolically when the mechanical properties of the callus increased. Strength testing in a cadaveric crural bone confirms the importance of callus volume. The serial strain gauge measurement technique was applied to a series of 23 cases treated with Hoffmann external fixation, 20 of which achieved bone healing. On the basis of the bone healing curve obtained with the strain gauge measurements, the healing process is classified into five types. PMID:24822815

  9. Kan Doppler-ultralyd erstatte strain gauge til måling af systolisk ankelblodtryk?

    Sørensen, T L; Perner, A; Hansen, L;

    1992-01-01

    Traditionally, strain gauge technique is used in Denmark to measure ankle blood pressure, a method requiring both time and well-trained personnel. In a study involving 90 limbs in 45 patients, this method was compared with ultrasonic technique using a portable 5 MHz Doppler. The reproducibility of...... Doppler ankle pressure measurement was similar to that found in strain gauge based studies. Two consecutive measurements may differ by 20 mmHg or in terms of ankle-brachial index by 0.15 before this is considered significant. No systematic variation was found between the two methods. Increasing...... difficulties were encountered with the Doppler technique at pressures below 50 mmHg. It is concluded that Doppler is a good alternative to strain gauge for measurement of ankle blood pressure....

  10. Automating the strain gauge data acquisition of dipole magnets during keying and skinning

    Automated data acquisition and processing of strain gauge data provides distinct advantages when compared to the manual system. Capturing of raw strain gauge data automatically from the dipole magnet while it is being keyed or skinned, allows us an immediate view of the relationship between the press pressures and the internal stresses of the magnet. This data is analyzed then converted to engineering units and displayed on the computer screen in real time. By continuously monitoring the strain gauges and the press pressure, movement within the magnet is detected and correlated with the applied force. This data allows striction and shifting of the coils to be detected. Because the data has been collected automatically, typographical errors in the data base are not a concern. The data in this soft form is available to be analyzed on other computers. The computer can control the press itself and automate the entire process

  11. Pressure Transducer with Au-Ni Thin-Film Strain Gauges

    Rajanna, K.; MOHAN.S; Nayak, MM; Gunasekaran, N.; Muthunayagam, AE

    1993-01-01

    Abstract-The behavior of a pressure transducer with Au-Ni (89:11) film as strain gauges have been studied. The effects of post-deposition heat treatment on the resistance of the thin-film strain gauges and hence the output performance of the pressure transducer are discussed. The effect of a repeated number of pressure cycles carried out over a period of eight months has also been reported. The maximum nonlinearity and the hysteresis is improved from 0.92% FSO to 0.06% FSO after 1000pressure ...

  12. Additive non-uniform random sampling in superimposed fiber Bragg grating strain gauge

    This paper demonstrates an additive non-uniform random sampling and interrogation method for dynamic and/or static strain gauge using a reflection spectrum from two superimposed fiber Bragg gratings (FBGs). The superimposed FBGs are designed to generate non-equidistant space of a sensing pulse train in the time domain during dynamic strain gauge. By combining centroid finding with smooth filtering methods, both the interrogation speed and accuracy are improved. A 1.9 kHz dynamic strain is measured by generating an additive non-uniform randomly distributed 2 kHz optical sensing pulse train from a mean 500 Hz triangular periodically changing scanning frequency. (paper)

  13. Luminescent Tension-Indicating Orthopedic Strain Gauges for Non-Invasive Measurements Through Tissue

    Anker, Jeffrey (Inventor); Rogalski, Melissa (Inventor); Anderson, Dakota (Inventor); Heath, Jonathon (Inventor)

    2015-01-01

    Strain gauges that can provide information with regard to the state of implantable devices are described. The strain gauges can exhibit luminescence that is detectable through living tissue, and the detectable luminescent emission can vary according to the strain applied to the gauge. A change in residual strain of the device can signify a loss of mechanical integrity and/or loosening of the implant, and this can be non-invasively detected either by simple visual detection of the luminescent emission or through examination of the emission with a detector such as a spectrometer or a camera.

  14. A COMPARISON OF METHODS USING STRAIN GAUGES TO MONITOR PHYSIOLOGICAL MOVEMENTS ON A HOSPITAL BED

    Vladimír Socha

    2014-10-01

    Full Text Available Two methods which are suitable to monitor the small movements of the patient in a horizontal position on the bed are compared. The methods use sensors based on strain gauge bridges configured to measure the torsion deformation and sensors based on strain gauge bridges configured to measure the bending deformation of two two-arm brackets. Both methods provide information about the patient's physiological movements. The methods were tested and compared in order to decide which methods may be most appropriate in clinical practice. The two methods have never been compared before, and the results can be used in development of the new methods of patient monitoring.

  15. Focal Plane Alignment Utilizing Optical CMM

    Liebe, Carl Christian; Meras, Patrick L.; Clark, Gerald J.; Sedaka, Jack J.; Kaluzny, Joel V.; Hirsch, Brian; Decker, Todd A.; Scholtz, Christopher R.

    2012-01-01

    In many applications, an optical detector has to be located relative to mechanical reference points. One solution is to specify stringent requirements on (1) mounting the optical detector relative to the chip carrier, (2) soldering the chip carrier onto the printed circuit board (PCB), and (3) installing the PCB to the mechanical structure of the subsystem. Figure 1 shows a sketch of an optical detector mounted relative to mechanical reference with high positional accuracy. The optical detector is typically a fragile wafer that cannot be physically touched by any measurement tool. An optical coordinate measuring machine (CMM) can be used to position optical detectors relative to mechanical reference points. This approach will eliminate all requirements on positional tolerances. The only requirement is that the PCB is manufactured with oversized holes. An exaggerated sketch of this situation is shown in Figure 2. The sketch shows very loose tolerances on mounting the optical detector in the chip carrier, loose tolerance on soldering the chip carrier to the PCB, and finally large tolerance on where the mounting screws are located. The PCB is held with large screws and oversized holes. The PCB is mounted loosely so it can move freely around. The optical CMM measures the mechanical reference points. Based on these measurements, the required positions of the optical detector corners can be calculated. The optical CMM is commanded to go to the position where one detector corner is supposed to be. This is indicated with the cross-hairs in Figure 2(a). This figure is representative of the image of the optical CMM monitor. Using a suitable tapping tool, the PCB is manually tapped around until the corner of the optical detector is at the crosshairs of the optical CMM. The CMM is commanded to another corner, and the process is repeated a number of times until all corners of the optical detector are within a distance of 10 to 30 microns of the required position. The situation

  16. Influence of nuclear radiation on strain gauges. Ueber den Kernstrahlungseinfluss auf Dehnungsmessstreifen

    Andreae, G.; Niessen, G.

    1987-01-01

    The influence of nuclear radiation on strain gauges is a superposition of a primary effect (generation of lattice defects resulting in an increase of resistance), a secondary effect (caused by radiation induced diffusion, which - depending on the material and its prior thermodynamic state - leads to a decrease or increase of resistance) and an after-effect (change of resistance after irradiation or between irradiations). The consequences of these effects depend on different parameters with mudual dependencies. Conclusion: Single strain gauges (quarter bridges) should not be used under nuclear radiation; the multitouch of - usually unknown - influence parameters makes a general prediction of the behaviour under radiation practically impossible. Particularly, it is impossible to apply methods such as choice of special materials or pretreatment procedures in order to get strain gauges for high radiation rates. Strain gauges in half-bridge configuration give - under optimum conditions a small difference of two large interfering quantities, which can hardly be estimated. Thus a prognosis of the performance under radiation remains doubtful. With 26 figs., 1 tab..

  17. High-temperature pressure sensors with strain gauges based on silicon whiskers

    Druzhinin A. A.; Kutrakov A. P.; Maryamova I. I.

    2012-01-01

    Studies aimed at the creating of piezoresistive pressure sensors based on silicon whiskers, operating at high temperatures were carried out. Using the glass adhesive for strain gauges mounting on spring elements of covar alloy gave the possibility to elevate the sensor’s operating temperature range. Several modifications of pressure sensors based on the proposed strain-unit design were developed.

  18. Design considerations for micromechanical sensors using encapsulated built-in resonant strain gauges

    Tilmans, Harrie A.C.; Bouwstra, Siebe; Fluitman, Jan H.J; Spence, Scott L.

    1990-01-01

    This paper describes the various design aspects for micromechanical sensors consisting of a structure with encapsulated built-in resonant strain gauges. Analytical models are used to investigate the effect of device parameters on the behaviour of a pressure sensor and a force sensor. The analyses in

  19. Gauge Factor and Stretchability of Silicon-on-Polymer Strain Gauges

    Nanshu Lu

    2013-07-01

    Full Text Available Strain gauges are widely applied to measure mechanical deformation of structures and specimens. While metallic foil gauges usually have a gauge factor slightly over 2, single crystalline silicon demonstrates intrinsic gauge factors as high as 200. Although silicon is an intrinsically stiff and brittle material, flexible and even stretchable strain gauges have been achieved by integrating thin silicon strips on soft and deformable polymer substrates. To achieve a fundamental understanding of the large variance in gauge factor and stretchability of reported flexible/stretchable silicon-on-polymer strain gauges, finite element and analytically models are established to reveal the effects of the length of the silicon strip, and the thickness and modulus of the polymer substrate. Analytical results for two limiting cases, i.e., infinitely thick substrate and infinitely long strip, have found good agreement with FEM results. We have discovered that strains in silicon resistor can vary by orders of magnitude with different substrate materials whereas strip length or substrate thickness only affects the strain level mildly. While the average strain in silicon reflects the gauge factor, the maximum strain in silicon governs the stretchability of the system. The tradeoff between gauge factor and stretchability of silicon-on-polymer strain gauges has been proposed and discussed.

  20. Blood pressure measurement of all five fingers by strain gauge plethysmography

    Hirai, M; Nielsen, S L; Lassen, N A

    1976-01-01

    The aim of the present paper was to study the methodological problems involved in measuring systolic blood pressure in all five fingers by the strain gauge technique. In 24 normal subjects, blood pressure at the proximal phalanx of finger I and both at the proximal and the intermediate phalanx of...

  1. The measurement of digital systolic blood pressure by strain gauge technique

    Nielsen, P E; Bell, G; Lassen, N A

    1972-01-01

    The systolic blood pressure on the finger, toe, and ankle has been measured by a strain gauge technique in 10 normal subjects aged 17-31 years and 14 normal subjects aged 43-57 years. The standard deviation in repeated measurements lies between 2 and 6 mm Hg. The finger pressure in the younger...

  2. Quasi-monolithic planar load cells using built-in resonant strain gauges

    Tilmans, H.A.C.; Elwenspoek, M.C.

    1993-01-01

    Two load cell designs are presented using resonant strain gauges providing a frequency output. One design is based on a four-point beam deflection jig. It offers high sensitivity, but suffers from robustness and impractical geometries for a broad force range. A modified planar design (typical dimens

  3. The Application of High-temperature Strain Gauges to the Measurements of Vibratory Stresses in Gas-turbine Buckets

    Kemp, R H; Morgan, W C; Manson, S S

    1947-01-01

    The feasibility of measuring the vibration in the buckets of a gas turbine under service conditions of speed and temperature was determined by use of a high temperature wire strain gauge cemented to a modified supercharger turbine bucket. A high-temperature wire strain gauge and the auxiliary mechanical and electrical equipment developed for the investigation are described.

  4. Fabrication of phosphorus doped polysilicon thin-film strain gauges using a 50 microns silicon substrate thickness

    Strain gauges fabrication using phosphorus doped polysilicon thin-film resistors was performed. Strain gauges transducers were designed to measure the strain in load cells, using a Wheatstone bridge circuit configuration. The strain and sensitivity measurements results for load cells application are described. A linear response and excellent repeatability were obtained.

  5. Long-time high-temperature strain gauge measurements on pipes and dissimilar welds for residual lifetime evaluation

    Residual lifetime determination of vessels and piping systems that are operated in the creep area is today of great interest. With capacitive high-temperature strain gauges it is possible to measure strains and creep velocities of the material at points of high load. This paper describes the fundamental behaviour of high-temperature strain gauges at different loading conditions. (orig.)

  6. CMM Interim Check Design of Experiments (U)

    Montano, Joshua Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-07-29

    Coordinate Measuring Machines (CMM) are widely used in industry, throughout the Nuclear Weapons Complex and at Los Alamos National Laboratory (LANL) to verify part conformance to design definition. Calibration cycles for CMMs at LANL are predominantly one year in length and include a weekly interim check to reduce risk. The CMM interim check makes use of Renishaw’s Machine Checking Gauge which is an off-the-shelf product simulates a large sphere within a CMM’s measurement volume and allows for error estimation. As verification on the interim check process a design of experiments investigation was proposed to test a couple of key factors (location and inspector). The results from the two-factor factorial experiment proved that location influenced results more than the inspector or interaction.

  7. A kinematic and strain gauge study of the reciprocal apparatus in the equine hind limb.

    van Weeren, P R; Jansen, M O; van den Bogert, A J; Barneveld, A

    1992-11-01

    Hind limb kinematics were recorded in five horses at walk and trot using an opto-electronic CODA-3 system. Simultaneously, in vivo strain in the completely tendinous peroneus tertius muscle was registered by implanted mercury-in-silastic strain gauges. The origin-insertion length patterns of the peroneus tertius were calculated from raw kinematic data and from data corrected for the error caused by skin displacement, and compared with the directly measured strain. The strain patterns calculated from externally measured kinematic data appeared to be in accordance with the directly measured strain gauge data. However, a correction for skin displacement is an obligatory prerequisite to obtain reliable results. The amplitudes of strain did not exceed 3% and appeared to be of about the same magnitude at both walk and trot. PMID:1400530

  8. Strain gauge validation experiments for the Sandia 34-meter VAWT (Vertical Axis Wind Turbine) test bed

    Sutherland, Herbert J.

    1988-08-01

    Sandia National Laboratories has erected a research oriented, 34- meter diameter, Darrieus vertical axis wind turbine near Bushland, Texas. This machine, designated the Sandia 34-m VAWT Test Bed, is equipped with a large array of strain gauges that have been placed at critical positions about the blades. This manuscript details a series of four-point bend experiments that were conducted to validate the output of the blade strain gauge circuits. The output of a particular gauge circuit is validated by comparing its output to equivalent gauge circuits (in this stress state) and to theoretical predictions. With only a few exceptions, the difference between measured and predicted strain values for a gauge circuit was found to be of the order of the estimated repeatability for the measurement system.

  9. Compartilhando protocolos: maquina CMM / CAD / CAM

    Pinheiro Beck, Joao Carlos; Lima da Silva, Isaac Newton; Baroni, Alexandre; Mazin Dias, Gilver

    2007-01-01

    A meta desta contribuição é a descrição da metodologia utilizada para compartilhar um software comercial de CAD/CAM, orientado à indústria mecânica, com um equipamento industrial de controle de qualidade tridimensional (CMM). As etapas necessárias a esta integração são apresentadas, passo a passo, para facilitar o entendimento e a visualização progressiva de cada uma das fases de estudo e análise. Tomando-se como referência este compartilhamento, efetuouse, como aplicação do proce...

  10. Strain Monitoring in Stiffened Composite Panels Using Embedded Fibre Optical and Strain Gauge Sensors

    Růžek, Roman; Kadlec, Martin; Tserpes, Konstantinos; Karachalios, Evanggelos

    2014-01-01

    International audience This paper describes an implemented structural health monitoring (SHM) system based on Fibre Optic Bragg Grating (FOBG) sensors and standard resistance strain gauges (SGs) placed onto/into a stiffened carbon fibre-reinforced polymer (CFRP) fuselage panel. The role of the FOBG sensor system was to monitor the structural integrity of the reference, impacted and fatigued panels under compression loading. The FOBG and/or SG sensors were placed (embedded or bonded) at var...

  11. Quasi-monolithic planar load cells using built-in resonant strain gauges

    Tilmans, Harrie A.C.; Elwenspoek, Miko

    1993-01-01

    Two load cell designs are presented using resonant strain gauges providing a frequency output. One design is based on a four-point beam deflection jig. It offers high sensitivity, but suffers from robustness and impractical geometries for a broad force range. A modified planar design (typical dimensions 1-10 mm) removes these drawbacks and in addition features built-in force reduction, overhead protection and compensation of common mode effects. Load ranges vary from high (1 500 N) to very lo...

  12. The Stress-Strain Condition Estimation of Detail in Crack Tip by Integral Strain Gauges

    Syzrantsev, V.; Syzrantseva, K.

    2016-04-01

    The paper considers the task of stress-strain condition calculation of experimental sample in fatigue crack tip on weld boundary at its cyclic deforming. For this task decision authors use the information obtained by original means of cyclic strains measurement: Integral Strain Gauges. The results of carried experimental researches are compared with data of stress-strain condition estimation of detail in crack tip calculated by Finish Element Method.

  13. Improvement of strain gauges micro-forces measurement using Kalman optimal filtering.

    Haddab, Yassine; Chen, Qiao; Lutz, Philippe

    2009-01-01

    International audience Manipulation of small components and assembly of Microsystems require force measurement. In the microworld (the world of very small components), signal/noise ratio is very low due to the weak amplitude of the signals. To be used in feedback control or in a micromanipulation system, a force sensor must allow static and dynamic measurements. In this paper, we present a micro-force measurement system based on the use of strain gauges and a Kalman optimal filter. Using a...

  14. Design considerations for micromechanical sensors using encapsulated built-in resonant strain gauges

    Tilmans, Harrie A.C.; Bouwstra, Siebe; Fluitman, Jan H.J; Spence, Scott L.

    1990-01-01

    This paper describes the various design aspects for micromechanical sensors consisting of a structure with encapsulated built-in resonant strain gauges. Analytical models are used to investigate the effect of device parameters on the behaviour of a pressure sensor and a force sensor. The analyses indicate that the sealing cap can have a strong degrading effect on the device performance if the thicknesses of the cap and of the supporting structure are of the same order of magnitude. A novel de...

  15. Capacitive strain gauges on flexible polymer substrates for wireless, intelligent systems

    Zeiser, R; T. Fellner; J. Wilde

    2014-01-01

    This paper presents a novel capacitive strain gauge with interdigital electrodes, which was processed on polyimide and LCP (liquid crystal polymer) foil substrates. The metallization is deposited and patterned using thin-film technology with structure sizes down to 15 μm. We determined linear strain sensitivities for our sensor configuration and identified the most influencing parameters on the output signal by means of an analytical approach. Finite-element method (FEM) sim...

  16. Force measurement using strain-gauge balance in a shock tunnel with long test duration.

    Wang, Yunpeng; Liu, Yunfeng; Luo, Changtong; Jiang, Zonglin

    2016-05-01

    Force tests were conducted at the long-duration-test shock tunnel JF12, which has been designed and built in the Institute of Mechanics, Chinese Academy of Sciences. The performance tests demonstrated that this facility is capable of reproducing a flow of dry air at Mach numbers from 5 to 9 at more than 100 ms test duration. Therefore, the traditional internal strain-gauge balance was considered for the force tests use in this large impulse facility. However, when the force tests are conducted in a shock tunnel, the inertial forces lead to low-frequency vibrations of the test model and its motion cannot be addressed through digital filtering because a sufficient number of cycles cannot be found during a shock tunnel run. The post-processing of the balance signal thus becomes extremely difficult when an averaging method is employed. Therefore, the force measurement encounters many problems in an impulse facility, particularly for large and heavy models. The objective of the present study is to develop pulse-type sting balance by using a strain-gauge sensor that can be applied in the force measurement of 100 ms test time, especially for the force test of the large-scale model. Different structures of the S-series (i.e., sting shaped balances) strain-gauge balance are proposed and designed, and the measuring elements are further optimized to overcome the difficulties encountered during the measurement of aerodynamic force in a shock tunnel. In addition, the force tests were conducted using two large-scale test models in JF12 and the S-series strain-gauge balances show good performance in the force measurements during the 100 ms test time. PMID:27250471

  17. RANCANG BANGUN SENSOR VISKOSITAS CAIRAN MENGGUNAKAN STRAIN GAUGE DENGAN PRINSIP SILINDER KONSENTRIS

    Farid Hananto Hananto

    2013-01-01

    Viskositas   adalah salah satu sifat penting suatu cairan. Pengukuran viskositas kebanyakan dilakukan dengan cara mekanik dan manual. Untuk memudahkan pengukuran dan digitalisasi pengukuran viskositas diperlukan sensor yang bisa mengubah besaran viskositas menjadi besaran listrik. Dalam penelitian ini telah di rancang sensor viskostas cairan menggunakan strain gauge menggunakan prinsip silinder konsentris. Silinder dalam menggunakan diameter 3 cm sedangkan silinder luar yang juga berf...

  18. Strain gauge measurements of blade resonance using eddy current excitation in a vacuum spin pit

    Russell, Scott A.

    2002-01-01

    As part of an on going High Cycle Fatigue program related to gas turbine engines, which is sponsored jointly by the Naval Air Systems Command and the Air Force, unsteady strain gauge measurements were made on a 37.5 inch diameter titanium rotor in the Naval Postgraduate School, Turbopropulsion Laboratory vacuum spin pit. Vibratory excitation was produced by a number of evenly spaced magnets positioned around the rotor perimeter, which generated eddy currents in the blades and associated magne...

  19. Measurement of displacements in large boreholes with a strain-gauged proving ring

    A strain-gauged proving-ring transducer was designed and deployed to measure small diametral displacements in 0.61-m diameter by 4.9-m deep boreholes in rock. The rock surrounding the boreholes was previously heated by storage of spent nuclear fuel assemblies and electrical resistance heaters. Borehole displacement measurements were made subsequent to removal of the spent fuel assemblies to document the rock response and to provide data for comparison with thermal-stress calculations. A transducer was designed to measure displacements in the range of 10 to 100 μm, to function in a time-varying temperature regime of 300 to 600C at a relative humidity of 100%, to be of low stiffness, and to be easily and quickly installed. The strain-gauged proving-ring technology provided a viable means of recording displacements in large (0.61 m) diameter boreholes in rock which are subjected to a time-varying thermal field. Design of a relatively simple transducer to measure borehole displacements was moderately successful. Inadquate environmental protection of the strain gauges resulted in 6 of 14 transducers failing with a mean life of 85 days. The surviving transducers performed adequately, based on comparisons of pretest and post-test calibration results. 5 refs., 3 figs., 1 tab

  20. Operational verification of a blow out preventer utilizing fiber Bragg grating based strain gauges

    Turner, Alan L.; Loustau, Philippe; Thibodeau, Dan

    2015-05-01

    Ultra-deep water BOP (Blowout Preventer) operation poses numerous challenges in obtaining accurate knowledge of current system integrity and component condition- a salient example is the difficulty of verifying closure of the pipe and shearing rams during and after well control events. Ascertaining the integrity of these functions is currently based on a manual volume measurement performed with a stop watch. Advances in sensor technology now permit more accurate methods of BOP condition monitoring. Fiber optic sensing technology and particularly fiber optic strain gauges have evolved to a point where we can derive a good representation of what is happening inside a BOP by installing sensors on the outside shell. Function signatures can be baselined to establish thresholds that indicate successful function activation. Based on this knowledge base, signal variation over time can then be utilized to assess degradation of these functions and subsequent failure to function. Monitoring the BOP from the outside has the advantage of gathering data through a system that can be interfaced with risk based integrity management software and/or a smart monitoring system that analyzes BOP control redundancies without the requirement of interfacing with OEM control systems. The paper will present the results of ongoing work on a fully instrumented 13-½" 10,000 psi pipe ram. Instrumentation includes commonly used pressure transducers, accelerometers, flow meters, and optical strain gauges. Correlation will be presented between flow, pressure, acceleration signatures and the fiber optic strain gauge's response as it relates to functional verification and component level degradation trending.

  1. Design and Analysis of a Compact Precision Positioning Platform Integrating Strain Gauges and the Piezoactuator

    Shunguang Wan

    2012-07-01

    Full Text Available Miniaturization precision positioning platforms are needed for in situ nanomechanical test applications. This paper proposes a compact precision positioning platform integrating strain gauges and the piezoactuator. Effects of geometric parameters of two parallel plates on Von Mises stress distribution as well as static and dynamic characteristics of the platform were studied by the finite element method. Results of the calibration experiment indicate that the strain gauge sensor has good linearity and its sensitivity is about 0.0468 mV/μm. A closed-loop control system was established to solve the problem of nonlinearity of the platform. Experimental results demonstrate that for the displacement control process, both the displacement increasing portion and the decreasing portion have good linearity, verifying that the control system is available. The developed platform has a compact structure but can realize displacement measurement with the embedded strain gauges, which is useful for the closed-loop control and structure miniaturization of piezo devices. It has potential applications in nanoindentation and nanoscratch tests, especially in the field of in situ nanomechanical testing which requires compact structures.

  2. Managerial and Organizational Assumptions in the CMM's

    Rose, Jeremy; Aaen, Ivan; Nielsen, Peter Axel

    2008-01-01

    Thinking about improving the management of software development in software firms is dominated by one approach: the capability maturity model devised and administered at the Software Engineering Institute at Carnegie Mellon University. Though CMM, and its replacement CMMI are widely known and used...... of management thinking about large production and manufacturing organisations (particularly in America) in the late industrial age. Many of the difficulties reported with CMMI can be attributed basing practice on these assumptions in organisations which have different cultures and management...... traditions, perhaps in different countries operating different economic and social models. Characterizing CMMI in this way opens the door to another question: are there other sets of organisational and management assumptions which would be better suited to other types of organisations operating in other...

  3. Effect of axial loads on implant-supported partial fixed prostheses by strain gauge analysis

    Luis Gustavo Oliveira de Vasconcellos

    2011-12-01

    Full Text Available OBJECTIVES: The present study used strain gauge analysis to perform an in vitro evaluation of the effect of axial loading on 3 elements of implant-supported partial fixed prostheses, varying the type of prosthetic cylinder and the loading points. MATERIAL AND METHODS: Three internal hexagon implants were linearly embedded in a polyurethane block. Microunit abutments were connected to the implants applying a torque of 20 Ncm, and prefabricated Co-Cr cylinders and plastic prosthetic cylinders were screwed onto the abutments, which received standard patterns cast in Co-Cr alloy (n=5. Four strain gauges (SG were bonded onto the surface of the block tangentially to the implants, SG 01 mesially to implant 1, SG 02 and SG 03 mesially and distally to implant 2, respectively, and SG 04 distally to implant 3. Each metallic structure was screwed onto the abutments with a 10 Ncm torque and an axial load of 30 kg was applied at five predetermined points (A, B, C, D, E. The data obtained from the strain gauge analyses were analyzed statistically by RM ANOVA and Tukey's test, with a level of significance of p<0.05. RESULTS: There was a significant difference for the loading point (p=0.0001, with point B generating the smallest microdeformation (239.49 µε and point D the highest (442.77 µε. No significant difference was found for the cylinder type (p=0.748. CONCLUSIONS: It was concluded that the type of cylinder did not affect in the magnitude of microdeformation, but the axial loading location influenced this magnitude.

  4. Strain gauges of GaSb-FeGa1.3 eutectic composites

    Aliyev, M.I.; Khalilova, A. A.; Arasly, D. H.; Rahimov, R. N.; Tanoğlu, Metin; ÖZYÜZER, Lütfi

    2004-01-01

    A needle-shaped metallic FeGa1.3 phase oriented in a specific direction and uniformly distributed within a GaSb matrix was grown by a vertical Bridgman method. Strain-gauge characteristics, such as strain-sensitivity coefficient (S), temperature coefficient of strain sensitivity (TCS) and temperature coefficient of resistance, of GaSb and GaSb-FeGa1.3 eutectic alloy have been investigated in the range of 200 to 400 K under deformation up to strains of 1.3 × 10-3. The value of S of the GaSb-Fe...

  5. Strain gauge pack in process measurement system for the collider quadrupole, design and technology transfer

    The in process measurement system that is described below was designed to monitor the strain gauge instrumentation collar pack during all phases of quadrupole magnet manufacture. The primary goal was to implement a monitoring system that incorporated standard measurement techniques while maintaining signal integrity. The flexibility and robustness required in a production environment were taken into account throughout the design and implementation. All major components were chosen from commercially available supplies. The driving software was chosen to provide a user friendly interface while keeping software development efforts to a minimum without sacrificing adaptability

  6. 耐高温多晶硅应变计%Temperature-resistant polysilicon strain gauge

    孙凤玲; 田雷; 孙学智; 王善慈

    2001-01-01

    Polysilicon strain gauge being applied to special environment isintroduced,including principle,design,manufacture technology and bonding method.It features in resistance to high temperature up to 250?℃, small volume and expedient installation.The strain gauge has been used to inspect slot weld of boiler in power station, the performance is better in practical application.%介绍了一种适用于特殊环境进行高温测量的多晶硅应变计的原理、设计、制作工艺及粘贴方法。它的特点是耐高温(可用在温度达250℃的环境中)、体积小、安装方便。该种应变计已用于检测电站锅炉焊缝的牢固程度,在实际应用中性能较好。

  7. A High Performance Torque Sensor for Milling Based on a Piezoresistive MEMS Strain Gauge

    Qin, Yafei; Zhao, Yulong; Li, Yingxue; Zhao, You; Wang, Peng

    2016-01-01

    In high speed and high precision machining applications, it is important to monitor the machining process in order to ensure high product quality. For this purpose, it is essential to develop a dynamometer with high sensitivity and high natural frequency which is suited to these conditions. This paper describes the design, calibration and performance of a milling torque sensor based on piezoresistive MEMS strain. A detailed design study is carried out to optimize the two mutually-contradictory indicators sensitivity and natural frequency. The developed torque sensor principally consists of a thin-walled cylinder, and a piezoresistive MEMS strain gauge bonded on the surface of the sensing element where the shear strain is maximum. The strain gauge includes eight piezoresistances and four are connected in a full Wheatstone circuit bridge, which is used to measure the applied torque force during machining procedures. Experimental static calibration results show that the sensitivity of torque sensor has been improved to 0.13 mv/Nm. A modal impact test indicates that the natural frequency of torque sensor reaches 1216 Hz, which is suitable for high speed machining processes. The dynamic test results indicate that the developed torque sensor is stable and practical for monitoring the milling process. PMID:27070620

  8. RANCANG BANGUN SENSOR VISKOSITAS CAIRAN MENGGUNAKAN STRAIN GAUGE DENGAN PRINSIP SILINDER KONSENTRIS

    Farid Hananto Hananto

    2013-05-01

    Full Text Available Viskositas   adalah salah satu sifat penting suatu cairan. Pengukuran viskositas kebanyakan dilakukan dengan cara mekanik dan manual. Untuk memudahkan pengukuran dan digitalisasi pengukuran viskositas diperlukan sensor yang bisa mengubah besaran viskositas menjadi besaran listrik. Dalam penelitian ini telah di rancang sensor viskostas cairan menggunakan strain gauge menggunakan prinsip silinder konsentris. Silinder dalam menggunakan diameter 3 cm sedangkan silinder luar yang juga berfungsi sebagai tempat cairan sampel berdiameter 4 cm. Silinder dalam dihubungkan dengan pelat pegas oleh sebuah as yang mana pada pegas tersebut dilekatkan sensor strain gauge. Silinder luar sebagai tempat sampel cairan dihubungkan ke sebuah motor yang dapat berputar konstan. Putaran silinder luar ini akan membuat cairan ikut berputar dan juga akan menyeret silinder dalam bergeser memutar. Gaya yang diterima oleh silinder dalam ini salah satunya tergantung pada viskositas dari cairan ini yang nantinya bisa dibaca oleh sensor strain gage yang dilekatkan pada pegas silinder dalam. Dari hasil penelitian didapatkan data bahwa tegangan keluaran rata-rata untuk sensor ini didapatkan sebesar 1,2 mvolt/cPois. Yang ini berarti setiap 1 cPois viskostas cairan akan menghasilkan tegangan sebesar 1,2 mili volt.

  9. A High Performance Torque Sensor for Milling Based on a Piezoresistive MEMS Strain Gauge.

    Qin, Yafei; Zhao, Yulong; Li, Yingxue; Zhao, You; Wang, Peng

    2016-01-01

    In high speed and high precision machining applications, it is important to monitor the machining process in order to ensure high product quality. For this purpose, it is essential to develop a dynamometer with high sensitivity and high natural frequency which is suited to these conditions. This paper describes the design, calibration and performance of a milling torque sensor based on piezoresistive MEMS strain. A detailed design study is carried out to optimize the two mutually-contradictory indicators sensitivity and natural frequency. The developed torque sensor principally consists of a thin-walled cylinder, and a piezoresistive MEMS strain gauge bonded on the surface of the sensing element where the shear strain is maximum. The strain gauge includes eight piezoresistances and four are connected in a full Wheatstone circuit bridge, which is used to measure the applied torque force during machining procedures. Experimental static calibration results show that the sensitivity of torque sensor has been improved to 0.13 mv/Nm. A modal impact test indicates that the natural frequency of torque sensor reaches 1216 Hz, which is suitable for high speed machining processes. The dynamic test results indicate that the developed torque sensor is stable and practical for monitoring the milling process. PMID:27070620

  10. Development of strain gauge evaluation channels for use in dynamic testing of shipping casks

    The Transportation System Development Department at Sandia National Laboratories (SNL) frequently evaluates the structural response of casks being developed to transport radioactive materials. A major part of this activity includes gathering instrumentation data from dynamic impact tests of cask models. The acquisition of reliable, high-quality instrumentation data is an important component of cask certification. One method to evaluate instrumentation error during testing is to include evaluation channels for the various structural transducers. Evaluation channels have been produced by some manufacturers of accelerometers used for structural evaluations of casks and are commercially available. These particular devices produce very low output or no output to applied shock acceleration. However, it was found that a packaged strain gauge evaluation channel is not commercially available. Consequently, strain gauge evaluation channels have been developed at SNL to evaluate non-strain-induced resistance changes from environmental factors that could affect resistance strain measurement data. These unwanted nonstrain-induced resistance changes could be caused, for example, by resistance changes in the interconnecting cabling, electromagnetic noise, or grounding effects

  11. A novel compliance measurement in radial arteries using strain-gauge plethysmography

    We propose a novel method for assessing the compliance of the radial artery by using a two-axis mechanism and a standard positioning procedure for detecting the optimal measuring site. A modified sensor was designed to simultaneously measure the arterial diameter change waveform (ADCW) and pressure pulse waveform with a strain gauge and piezoresistor. In the x-axis scanning, the sensor could be placed close to the middle of the radial artery when the ADCW reached the maximum amplitude. In the z-axis scanning, the contact pressure was continuously increased for data measurement. Upon the deformation of the strain gauge following the change in the vascular cross-section, the ADCW was transferred to the change of the vascular radius. The loaded strain compliance of the radial artery (Cstrain) can be determined by dividing the dynamic changed radius by the pulse pressure. Twenty-three untreated, mild or moderate hypertensive patients aged 29–85 were compared with 14 normotensive patients aged 25–62. The maximum strain compliance between the two groups was significantly different (p < 0.005). Of the hypertensive patients, 14 were at risk of developing hyperlipidemia. There was a significant difference between this and the normotension group (p < 0.005)

  12. A High Performance Torque Sensor for Milling Based on a Piezoresistive MEMS Strain Gauge

    Yafei Qin

    2016-04-01

    Full Text Available In high speed and high precision machining applications, it is important to monitor the machining process in order to ensure high product quality. For this purpose, it is essential to develop a dynamometer with high sensitivity and high natural frequency which is suited to these conditions. This paper describes the design, calibration and performance of a milling torque sensor based on piezoresistive MEMS strain. A detailed design study is carried out to optimize the two mutually-contradictory indicators sensitivity and natural frequency. The developed torque sensor principally consists of a thin-walled cylinder, and a piezoresistive MEMS strain gauge bonded on the surface of the sensing element where the shear strain is maximum. The strain gauge includes eight piezoresistances and four are connected in a full Wheatstone circuit bridge, which is used to measure the applied torque force during machining procedures. Experimental static calibration results show that the sensitivity of torque sensor has been improved to 0.13 mv/Nm. A modal impact test indicates that the natural frequency of torque sensor reaches 1216 Hz, which is suitable for high speed machining processes. The dynamic test results indicate that the developed torque sensor is stable and practical for monitoring the milling process.

  13. Measurement of high temperature strain by the laser-speckle strain gauge

    Yamaguchi, I.

    1984-01-01

    By using the laser-speckle strain gauge, the strain of metal at the temperature lower than 250 C is measured. The principle of the gauge is to measure the expansion or contraction of the fine structures of surface by detecting the resultant speckle displacement in an optoelectronic way, whereby the effect of rigid-body motion is automatically cancelled out with the aid of a differential detection system. A transportable apparatus was built and a comparison experiment performed with a resistance strain gauge at room temperature. It has a strain sensitivity of .00002, a gauge length smaller than 1 mm, and no upper limit in a range of strain measurement. In the measurement of high-temperature strain it is free from the need for a dummy gauge and insensitive to an electric drift effect. As examples of strain measurement at high-temperature, thermal expansion and contraction of a top of a soldering iron are measured. The interval of the measurement can be made at shortest 1.6 sec. and the change in the strain is clearly followed until the ultimate stationary temperature is reached.

  14. A thin-film aluminum strain gauges array in a flexible gastrointestinal catheter for pressure measurements

    Sousa, P. J.; Silva, L. R.; Pinto, V. C.; Goncalves, L. M.; Minas, G.

    2016-08-01

    This paper presents an innovative approach to measure the pressure patterns associated with the motility and peristaltic movements in the upper gastrointestinal tract. This approach is based on inexpensive and easy to fabricate thin-film aluminum strain gauge pressure sensors using a flexible polyimide film (Kapton) as substrate and SU-8 structural support. These sensors are fabricated using well-established and standard photolithographic and wet etching techniques. Each sensor has a 3.4 mm2 area, allowing a fabrication process with a high level of sensors integration (four sensors in 1.7 cm), which is suitable for placing them in a single catheter. These strain gauges bend when pressure is applied and, consequently, their electrical resistance is changed. The fabricated sensors feature an almost linear response (R 2  =  0.9945) and an overall sensitivity of 6.4 mV mmHg‑1. Their readout and control electronics were developed in a flexible Kapton ribbon cable and, together with the sensors, bonded and wrapped around a catheter-like structure. The sequential acquisition of the different signals is carried by a microcontroller with a 10 bit ADC at a sample rate of 250 Hz per‑1 sensor. The signals are presented in a user friendly interface developed using the integrated development environment software, QtCreator IDE, for better visualization by physicians.

  15. Flexible gastrointestinal motility pressure sensors based on aluminum thin-film strain-gauge arrays

    This paper reports on an innovative approach to measuring intraluminal pressure in the upper gastrointestinal (GI) tract, especially monitoring GI motility and peristaltic movements. The proposed approach relies on thin-film aluminum strain gauges deposited on top of a Kapton membrane, which in turn lies on top of an SU-8 diaphragm-like structure. This structure enables the Kapton membrane to bend when pressure is applied, thereby affecting the strain gauges and effectively changing their electrical resistance. The sensor, with an area of 3.4 mm2, is fabricated using photolithography and standard microfabrication techniques (wet etching). It features a linear response (R2 = 0.9987) and an overall sensitivity of 2.6 mV mmHg−1. Additionally, its topology allows a high integration capability. The strain gauges’ responses to pressure were studied and the fabrication process optimized to achieve high sensitivity, linearity, and reproducibility. The sequential acquisition of the different signals is carried out by a microcontroller, with a 10-bit ADC and a sample rate of 250 Hz. The pressure signals are then presented in a user-friendly interface, developed using the Integrated Development Environment software, QtCreator IDE, for better visualization by physicians. (paper)

  16. Small angle X-ray scattering coupled with in situ electromechanical probing of nanoparticle-based resistive strain gauges.

    Decorde, Nicolas; Sangeetha, Neralagatta M; Viallet, Benoit; Viau, Guillaume; Grisolia, Jérémie; Coati, Alessandro; Vlad, Alina; Garreau, Yves; Ressier, Laurence

    2014-12-21

    A comprehensive study on the electromechanical behavior of nanoparticle-based resistive strain gauges in action through normal and grazing incidence small angle X-ray scattering (SAXS/GISAXS) investigations is presented. The strain gauges were fabricated from arrays of colloidal gold nanoparticle (NP) wires assembled on flexible polyethylene terephthalate and polyimide substrates by convective self-assembly. Microstructural changes (mean interparticle distance variations) within these NP wires under uniaxial stretching estimated by SAXS/GISAXS are correlated to their macroscopic electrical resistance variations. SAXS measurements suggest a linear longitudinal extension and transversal contraction of the NP wires with applied strain (0 to ∼ 13%). The slope of this longitudinal variation is less than unity, implying a partial strain transfer from the substrate to the NP wires. The simultaneously measured electrical resistance of the strain gauges shows an exponential variation within the elastic domain of the substrate deformation, consistent with electron tunnelling through the interparticle gaps. A slower variation observed within the plastic domain suggests the formation of new electronic conduction pathways. Implications of transversal contraction of the NP wires on the directional sensitivities of strain gauges are evaluated by simulating electronic conduction in models mimicking a realistic NP arrangement. A loss of directionality of the NP-based strain gauges due to transversal current flow within the NP wires is deduced. PMID:25371292

  17. Sensing Study of An Optical Fiber Strain Gauge%光纤应变片的传感研究

    李川; 张以谟; 李欣; 刘铁根; 陈希明

    2001-01-01

    This paper brings out an optic fiber s train sensor based on an optic fiber strain gauge.Monitoring the bending loss of optic fiber bonded on the optic fiber strain gauge,the strain and the deformation can be obtained.The measuring results for the micro-displacement an d the strain indicate that the optic fiber strain gauge of fers a monitoring method both strain and distortion.And the strain response of the optic fiber strain gauge is more sensitive than the one of resistance strain gauge.%本文设计了基于光纤应变片的光纤应变传感器,方法基于测量粘贴于其上的光纤弯曲损耗来获取应变量和形变量。通过微位移架上的位移测量实验与悬臂梁上的应变测量实验,结果表明该光纤应变片提供了同时适合于应变与形变的检测方式。值得一提的是,该光纤应变片的应变响应灵敏度优于电阻应变片的应变响应。

  18. An Inspection Information Integration System of CAD and CMM

    WANG Junying; WANG Jianmei

    2006-01-01

    Manual definition of inspection feature in Coordinate Measuring Machines (CMM) is time-consuming and error-potential. Since CAD model contains all design data, an integration system of CAD/CMM is constructed to automate above process. First, tolerance feature and its attributes, including tolerance type, value and tag of related geometry, are extracted from CAD model and written to QDAS file, based on feature technology. The tags are then added as attribute to related geometry in CAD model. Thereby they can be automatically remarked in the parameter list of their corresponding geometric item when exporting STEP file. At last, both STEP and QDAS file are imported to CMM system. Based on the mapping between geometric and tolerance feature in neutral files, inspection features can be recognized by CMM without manual interruption. The system has been implemented on Unigraphics platform, and proved to applicable for all types of tolerance and geometry.

  19. 激光散斑应变仪应用实验%The Experiments on the Laser Speckle Strain Gauge

    杨文淑; 张以谟; 马佳光

    2000-01-01

    介绍了激光散斑应变仪的功能及技术特性,还详细描述了如何用激光散斑应变仪作材料变形实验,并与传统方法作比较.文章最后给出了一些实验结果.%The functions and technical features of Laser Speckle Strain Gauge are introduced. The deformation experiments which are carried out by the Laser Speckle Strain Gauge is described in the paper. Some experimental results are presented.

  20. Space-compatible strain gauges as an integration aid for the James Webb Space Telescope Mid-Infrared Instrument

    Samara-Ratna, Piyal; Sykes, Jon; Bicknell, Chris;

    2015-01-01

    Mid-Infrared Instrument is its primary structure, which provides both a stable platform and thermal isolation for the scientific instruments. The primary structure contains strain-absorbing flexures and this article summarises how these have been instrumented with a novel strain gauge system designed...... to protect the structure from damage. Compatible with space flight requirements, the gauges have been used in both ambient and cryogenic environments and were successfully used to support various tasks including integration to the spacecraft. The article also discusses limitations to using the strain...... gauge instrumentation and other implications that should be considered if such a system is to be used for similar applications in future....

  1. Characterization of zeolite-trench-embedded microcantilevers with CMOS strain gauge for integrated gas sensor applications

    Inoue, Shu; Denoual, Matthieu; Awala, Hussein; Grand, Julien; Mintova, Sveltana; Tixier-Mita, Agnès; Mita, Yoshio

    2016-04-01

    Custom-synthesized zeolite is coated and fixed into microcantilevers with microtrenches of 1 to 5 µm width. Zeolite is a porous material that absorbs chemical substances; thus, it is expected to work as a sensitive chemical-sensing head. The total mass increases with gas absorption, and the cantilever resonance frequency decreases accordingly. In this paper, a thick zeolite cantilever sensor array system for high sensitivity and selectivity is proposed. The system is composed of an array of microcantilevers with silicon deep trenches. The cantilevers are integrated with CMOS-made polysilicon strain gauges for frequency response electrical measurement. The post-process fabrication of such an integrated array out of a foundry-made CMOS chip is successful. On the cantilevers, three types of custom zeolite (FAU-X, LTL, and MFI) are integrated by dip and heating methods. The preliminary measurement has shown a clear shift of resonance frequency by the chemical absorbance of ethanol gas.

  2. Measurement of internal forces in superconducting accelerator magnets with strain gauge transducers

    An improved method has been developed for the measurement of internal forces in superconducting accelerator magnets, in particular the compressive stresses in coils and the end restraint forces on the coils. The transducers have been designed to provide improved sensitivity to purely mechanical strain by using bending mode deflections for sensing the applied loads. Strain gauge resistance measurements are made with a new system that eliminates sources of errors due to spurious resistance changes in interconnecting wiring and solder joints. The design of the transducers and their measurement system is presented along with a discussion of the method of compensation for thermal and magnetic effects, methods of calibration with typical calibration data, and measured effects in actual magnets of the thermal stress changes from cooldown and the Lorentz forces during magnet excitation

  3. Microfabrication and characterization of spray-coated single-wall carbon nanotube film strain gauges

    We present the design, fabrication, and characterization results of single-wall carbon nanotube (SWCNT) film strain gauges for potential applications as highly sensitive strain, weight, or pressure sensors on the macro-scale. A batch microfabrication process was developed for practical device construction and packaging using spray-coated SWCNTs and a conventional semiconductor process. The prototype was characterized using a commercial metal foil gauge with tensile and compressive testing on a binocular load cell. Our test results demonstrated that the proposed SWCNT film gauges have a linear relationship between resistance changes and externally applied strain. The gauge factor ranged from 7.0 to 16.4 for four different micro-grid configurations, indicating that the maximum strain sensitivity of the prototype was approximately eight times greater than that of commercial gauges.

  4. Measurement of local values of strains of the briquette by means of special resistance strain gauges

    Rysz, Jozef

    1997-02-01

    Local measurement of the coal briquette strains during its destruction caused by sudden decrease of pressure of gas filling pores is difficult, because of high strain of coal (exceeds 16%), which results in bursting. A special type of an resistance-strain gauge, which is pressed into a defined position during briquette preparation was elaborated. This gauge is deformed just as the surrounding coal. The strain is measured as a difference in resistance of a mixture of coal grains (briquette material) and short, 8 micrometers dia. graphite fibers. A ca. 0.5 mm thick and ca. 1 mm long gauge was prepared. Its initial resistance constituted several hundreds ohms. The resistance vs. strain dependence is not linear but stable enough in time and does not depend on the type of gas filling briquette pores (e.g. CO2 and He).

  5. [Serial strain gauge measurement of bone healing in Hoffmann external fixation].

    Nishimura, N

    1984-01-01

    Since 1978, the author has applied Hoffmann external fixation to the treatment of open fractures and infected pseudoarthrosis of long bones in the lower limbs, but has some difficulties in determining when weight bearing should be started after operation, how much weight bearing should be and when the pin should be removed. As new method to mechanically analyze the callus strength, I tried to estimate the amount of strain at intervals of 2 to 3 weeks, beginning from the second week after operation, by bending or compressing the fracture site through the strain gauge glued to the middle of the external fixator's connecting rod. From a strength test by means of a model of fracture using a vinyl chloride pipe and also from a study of computer calculation using the model of plane beam structure for architectural design, it was found that the amount of the strain on the connecting rod decreased hyperbolically when the mechanical properties of the callus increased, and that it became constant when the mechanical properties of the callus reached 50% of the intact bone. The strength test using an cadaveric skin bone demonstrated that the callus volume was one of the most important and affecting factor. Twenty-three cases were treated by Hoffmann external fixation, and the bone healing was achieved in 20 of them. On the basis of the bone healing curve obtained by the serial strain gauge measurement in those cases, the bone healing process could be classified into 5 types: normal healing, slow healing, non-union, arrest in evolution and breakage of callus; and were employed as indexes in the post-operative rehabilitation program. PMID:6747402

  6. Strain gauge bonding technique of strain measurement using bonded resistance in HT-7U superconducting model coil

    Strain measurement using bonded resistance in HT-7U superconducting model coil goes along under low temperature (4.2 K), the authors choose WK-09-062TZ-120 strain gauge and M-Bond 600 adhesive made by Micro-Measurement INC. of America, then manage bonding technique properly and get satisfactory result

  7. Suggested Procedures for Installing Strain Gauges on Langley Research Center Wind Tunnel Balances, Custom Force Measuring Transducers, Metallic and Composite Structural Test Articles

    Moore, Thomas C., Sr.

    2004-01-01

    The character of force and strain measurement testing at LaRC is such that the types of strain gauge installations, the materials upon which the strain gauges are applied, and the test environments encountered, require many varied approaches. In 1997, a NASA Technical Memorandum (NASA TM 110327) was generated to provide the strain gauge application specialist with a listing of recommended procedures for strain gauging various transducers and test articles at LaRC. The technical memorandum offered here is an effort to keep the strain gauge user informed of new technological enhancements in strain-gauging methodology while preserving the strain-gauging guidelines set forth in the 1997 TM. This document provides detailed recommendations for strain gauging LaRC-designed balances and custom transducers, composite materials, cryogenic and high-temperature test articles, and selected non-typical or unique materials or test conditions. Additionally, one section offers details for installing Bragg-Grating type fiber-optic strain sensors for non-typical test scenarios.

  8. Performance Investigation of CMM Measurement Quality Using Flick Standard

    Salah H. R. Ali

    2014-01-01

    Full Text Available Quality of coordinate measuring machine (CMM in dimension and form metrology is designed and performed at the NIS. The experimental investigation of CMM performance is developed by using reference Flick standard. The measurement errors of corresponding geometric evaluation algorithm (LSQ, ME, MC, and MI and probe scanning speed (1, 2, 3, 4, and 5 mm/s are obtained through repeated arrangement, comparison, and judgment. The experimental results show that the roundness error deviation can be evaluated effectively and exactly for CMM performance by using Flick standard. Some of influencing quantities for diameter and roundness form errors may dominate the results at all fitting algorithms under certain circumstances. It can be shown that the 2 mm/s probe speed gives smaller roundness error than 1, 3, 4, and 5 mm/s within 0.2 : 0.3 μm. It ensures that measurement at 2 mm/s is the best case to satisfy the high level of accuracy in the certain condition. Using Flick standard as a quality evaluation tool noted a high precision incremental in diameter and roundness form indication. This means a better transfer stability of CMM quality could be significantly improved. Moreover, some error formulae of data sets have been postulated to correlate the diameter and roundness measurements within the application range. Uncertainty resulting from CMM and environmental temperature has been evaluated and confirmed the quality degree of confidence in the proposed performance investigation.

  9. Research on the FBG strain gauge used for the safety monitoring of high-temperature pressure pipes

    Cai, Qing-mu; Liu, Yue-ming; He, Zheng-yan; Chen, Zhong-you; Huang, Chang-qing; Lou, Jun; Tian, Wei-jian

    2012-10-01

    High temperature pressure pipes were widely used in the chemical, oil companies and power plants, but the pipe burst incidents occurred from time to time, which had caused some damages on people's lives and property. Thus, in this paper, with the aim to solve this problem, a FBG (FBG: Fiber Bragg Grating) strain gauge structure which consists of three FBGs is designed and fabricated based on the theoretical strain and stress analysis. The strain gauge can be used for the real-time surface strain monitoring of high temperature pressure pipes. In the strain gauge, the elastic hightemperature alloy(10MoWVNb) is chosen as the substrate. The three FBGs with a similar performance are fabricated on the substrate with the high-temperature glue. Among the three FBGs, FBG1 is used for the horizontal strain sensing of high temperature pressure pipes., FBG2 is used for the longitudinal strain of high temperature pressure pipes, and FGB3 is used for temperature compensation. The strain gauge has a feature of high temperature resistance, temperature compensation and two-dimensional strain measurement. The experiment result shows that : the sensing ranges of temperature is 0~300°C, the transverse strain sensitivity is 1.110nm/μɛ, the temperature sensitivity is 0.0213nm/°C; The longitudinal strain sensitivity is 1.104nm/μɛ, the temperature sensitivity is 0.0212nm/°C; the temperature sensitivity is 0.0103nm/°C. Therefore, the strain gauge can meet the needs of the high temperature and pressure pipes.

  10. Active buckling control of beams using piezoelectric actuators and strain gauge sensors

    In this paper, a finite element model incorporating active control techniques has been developed to stabilize the first two buckling modes of both a simply supported and a cantilevered beam. The goal is to increase the corresponding beam buckling loads by using piezoelectric actuators along with optimal feedback control. The uniform beams are bonded with two pairs of segmented piezoelectric actuators at the top and bottom. Resistive strain gauges are attached to the centres of the actuators as sensors. Measurements are taken using these, to estimate the system states. The beams are simply supported or cantilevered and subjected to a slowly increasing axial compressive load. Finite element formulations based on the classical Euler–Bernoulli beam theory and linear piezoelectric constitutive equations for the actuators are presented. The associated reduced-order modal equations and the state-space equations are derived for the design of a standard linear quadratic regulator (LQR). The finite element analysis and the active control simulation results are consistent with both theoretical analysis results and experimental data. The designed full state feedback LQR controller is shown to be successful in stabilizing the first two buckling modes of the beams. Also the control simulation shows that the present optimally located segmented actuator pairs along the beam are more effective for buckling control

  11. Experiment and Application of Resistance Strain Gauge%电阻应变片的实验与应用

    李巧真; 李刚; 韩钦泽

    2011-01-01

    Resistance strain gauge is one of widely used sensors, hence has became the important mean in non-electricity measurement. This paper introduced its operation principle, and characteristics of measuring circuits. Two examples were presented to explain the application of resistance strain gauge.%电阻应变片是广泛应用的传感元件之一,已成为非电量电测技术中重要的检测手段.介绍了其工作原理及测量电路的设计与特性,并通过两个实例说明了电阻应变片的应用.

  12. Investigation of nonlinearity as an error source in strain gauge measurements of high elongations, and comparison with other measuring methods

    High elongation measurement using strain gauges presents problems with regard to accuracy of results, emanating on the one hand from the measuring technique applied (bridge linearity at constant current or constant voltage), or from the strain gauge itself (k factor). Error correction has to take into account all parameters influencing the electric signal, as certain effects are opposite in their signs. The maximum deviations of the elongations measured by the various measuring devices in comparison with true elongation vary with the measuring technique applied, and within the elongation range investigated (0-0.1 m/m) may reach a maximum between 1 p.c. and 11 p.c.. Measurements with equipment using constant current or constant voltage supply have shown to be also appropriate in the high elongation range, if their specific errors within ≤ p.c. are duly corrected. (orig.)

  13. Very large strain gauges based on single layer MoSe2 and WSe2 for sensing applications

    Hosseini, Manouchehr; Elahi, Mohammad; Pourfath, Mahdi; Esseni, David

    2015-12-01

    Here, we propose a strain gauge based on single-layer MoSe2 and WSe2 and show that, in these materials, the strain induced modulation of inter-valley phonon scattering leads to large mobility changes, which in turn result in highly sensitive strain gauges. By employing density-functional theory bandstructure calculations, comprehensive scattering models, and the linearized Boltzmann equation, we explain the physical mechanisms for the high sensitivity to strain of the resistivity in single-layer MoSe2 and WSe2, discuss the reduction of the gauge factor produced by extrinsic scattering sources (e.g., chemical impurities), and propose ways to mitigate such sensitivity degradation.

  14. A Practical Monitoring System for the Structural Safety of Mega-Trusses Using Wireless Vibrating Wire Strain Gauges

    Hyo Seon Park; Hwan Young Lee; Se Woon Choi; Yousok Kim

    2013-01-01

    Sensor technologies have been actively employed in structural health monitoring (SHM) to evaluate structural safety. To provide stable and real-time monitoring, a practical wireless sensor network system (WSNS) based on vibrating wire strain gauges (VWSGs) is proposed and applied to a building under construction. In this WSNS, the data measured from each VWSG are transmitted to the sensor node via a signal line and then transmitted to the master node through a short-range wireless communicati...

  15. Underwater current leakage between encapsulated NiChrome tracks: Implications for strain-gauges and other implantable devices

    Vanhoestenberghe, A.; Bickerton, S.; Taylor, S. J. G.; Donaldson, N. D. N.

    2014-01-01

    We present the results of experiments aimed at identifying a suitable polymer for the encapsulation of thin-film strain gauges for underwater applications (with a view of using it in an instrumented bone fusion nail). The leakage currents across grooves cut (using a laser) in thin films of NiChrome over borosilicate glass were studied for encapsulated samples, immersed in water at 37 °C. The selected encapsulants were five silicone rubbers (of both medical and engineering grades), produced by...

  16. New bridge circuit-type detector to measure precise resistance change of strain gauge at low temperature and magnetic field

    Ohashi, Masashi; Kishii, Nobuya; Tateno, Shota

    2016-01-01

    We report a new highly accurate and versatile bridge-circuit-type detector that has a simple structure and demonstrates a low degree of error for measurements of thermal expansion and magnetostriction by the strain gauge method. As an example, a commercial physical property measurement system (PPMS) is combined with a compact bridge-circuit box. Thermal expansion and magnetostriction are calculated from the resistance of the bridge and bridge voltage, measured by the operation of a standard P...

  17. Machined and plastic copings in three-element prostheses with different types of implantabutment joints: a strain gauge comparative analysis

    Renato Sussumu Nishioka; Lea Nogueira Braulino de Melo Nishioka; Celina Wanderley Abreu; Luis Gustavo Oliveira Vasconcellos; Ivan Balducci

    2010-01-01

    OBJECTIVE: Using strain gauge (SG) analysis, the aim of this in vitro study was quantify the strain development during the fixation of three-unit screw implant-supported fixed partial dentures, varying the types of implant-abutment joints and the type of prosthetic coping. The hypotheses were that the type of hexagonal connection would generate different microstrains and the type of copings would produce similar microstrains after prosthetic screws had been tightened onto microunit abutments....

  18. Network of flexible capacitive strain gauges for the reconstruction of surface strain

    Monitoring of surface strain on mesosurfaces is a difficult task, often impeded by the lack of scalability of conventional sensing systems. A solution is to deploy large networks of flexible strain gauges, a type of large area electronics. The authors have recently proposed a soft elastomeric capacitor (SEC) as an economical skin-type solution for large-scale deployment onto mesosurfaces. The sensing principle is based on a measurable change in the sensor’s capacitance upon strain. In this paper, we study the performance of the sensor at reconstructing surface strain map and deflection shapes. A particular feature of the sensor is that it measures surface strain additively, because it is not utilized within a Wheatstone bridge configuration. An algorithm is proposed to decompose the additive in-plane strain measurements from the SEC into principal components. The algorithm consists of assuming a polynomial shape function, and deriving the strain based on Kirchhoff plate theory. A least-squares estimator (LSE) is used to minimize the error between the assumed model and the SEC signals after the enforcement of boundary conditions. Numerical simulations are conducted on a symmetric rectangular cantilever thin plate under symmetric and asymmetric static loads to demonstrate the accuracy and real-time applicability of the algorithm. The performance of the algorithm is further examined on an asymmetric cantilever laminated thin plate constituted with orthotropic materials mimicking a wind turbine blade, and subjected to a non-stationary wind load. Results from simulations show good performance of the algorithm at reconstructing the surface strain maps for both in-plane principal strain components, and that it can be applied in real time. However, its performance can be improved by strengthening assumptions on boundary conditions. The algorithm exhibits robustness in performance with respect to load and noise in signals, except when most of the sensors’ signals are

  19. Network of flexible capacitive strain gauges for the reconstruction of surface strain

    Wu, Jingzhe; Song, Chunhui; Saleem, Hussam S.; Downey, Austin; Laflamme, Simon

    2015-05-01

    Monitoring of surface strain on mesosurfaces is a difficult task, often impeded by the lack of scalability of conventional sensing systems. A solution is to deploy large networks of flexible strain gauges, a type of large area electronics. The authors have recently proposed a soft elastomeric capacitor (SEC) as an economical skin-type solution for large-scale deployment onto mesosurfaces. The sensing principle is based on a measurable change in the sensor’s capacitance upon strain. In this paper, we study the performance of the sensor at reconstructing surface strain map and deflection shapes. A particular feature of the sensor is that it measures surface strain additively, because it is not utilized within a Wheatstone bridge configuration. An algorithm is proposed to decompose the additive in-plane strain measurements from the SEC into principal components. The algorithm consists of assuming a polynomial shape function, and deriving the strain based on Kirchhoff plate theory. A least-squares estimator (LSE) is used to minimize the error between the assumed model and the SEC signals after the enforcement of boundary conditions. Numerical simulations are conducted on a symmetric rectangular cantilever thin plate under symmetric and asymmetric static loads to demonstrate the accuracy and real-time applicability of the algorithm. The performance of the algorithm is further examined on an asymmetric cantilever laminated thin plate constituted with orthotropic materials mimicking a wind turbine blade, and subjected to a non-stationary wind load. Results from simulations show good performance of the algorithm at reconstructing the surface strain maps for both in-plane principal strain components, and that it can be applied in real time. However, its performance can be improved by strengthening assumptions on boundary conditions. The algorithm exhibits robustness in performance with respect to load and noise in signals, except when most of the sensors’ signals are

  20. Studying the Vibrostressed State of the Elements of Gas Turbine Engine Using a High Temperature Film-Type Resistance Strain Gauge

    ГУСЕВ Ю.А.; Кахраи, Камбиз; Прочан, Г. А.; ЯКОВЛЕВ Ю.А.

    2015-01-01

    The conditions under which the vibrostressed state of the turbine blades of gas turbine engine (GTE) is investigated using the resistance strain gauge have been given. The consideration was given to resistance strain gauge with the film sensitive platinum and metal ceramic-based elements and the substrate-type isolator made of high temperature cement of a phosphate hardening and the methods of the investigation of the vibrodeformations of GTE elements including their application. The vibratio...

  1. Data analysis of the strain gauges system of the W7-X superconducting coils

    Wendelstein 7-X (W7-X) is an advanced stellarator which is presently under development and construction at the Max-Planck-Institut fuer Plasmaphysik in Greifswald, Germany. The W7-X is a magnetic confinement device where the main magnetic configuration is produced by a set of 70 superconducting coils, arranged in five identical modules. A module can be further divided in two half-modules, each made up of five non-planar coils (Types 1-5) and two planar coils (Types A and B). To monitor the integrity of the coil system and its neighbouring components during the operational and accidental transients of the W7-X device, a strain gauges (SG) system was included in the machine design, distributed in those positions which will have, realistically and according to finite elements (FE) calculations, the most high stress levels. Specifically, each superconducting coil of the W7-X system is monitored via a set of four SG sensors which are firmly attached in specific locations of the coil steel casings. Each sensor consists of a bridge of two individual foil gauges, connected so to compensate the effects of the broad excursion from room to cryogenic temperature, and the four sensors are arranged in a double redundant array for increased reliability. To estimate the response of the SG system in terms of accuracy and precision, so actually in terms of degree of conformity to FE anticipated results and degree of repeatability of similar measurements, and also to explain some unpredictable results obtained at cryogenic temperature, a comprehensive data analysis was carried on, based on the SG data collected during the cold acceptance tests of the W7-X superconducting magnets. The cold testing phase was, indeed, a valuable tool to verify the response of the SG system in the framework of the overall acceptance process of the coils. Thanks to the consistent data pool, a meaningful statistical analysis was possible, and the behaviour of the SG system was observed from a new

  2. Summary of ANSYS and Strain Gauge Results for the EC Calorimeter OH and MH Modules

    The OH and MH modules of the EC calorimeter consist essentially of metal boxes containing calorimetry plates. These plates can contribute to the module behavior only in compression, with this effect being enhanced if the plates are compressively preloaded against the skin of the box prior to assembly. The finite element method can be applied in the analysis of these modules. Its advantages are: 1. The structural components can be modeled with less simplification than beam theory allows. The angled faces of the OH modules can be represented exactly, and the shear deflections inherent in short, deep beams will be a natural part of the solution. 2. The finite element method can be subjected to any number of realistic loadings. 3. With proper mesh density relevant stresses can be extracted. The disadvantages of the method are that exact modeling of the internal plates is difficult, time consuming, and computationally expensive. It is of interest, then, to verify how well a simple model of the structural components only (i.e., the skin, endplates, and any structural internal plates) predicts deflections and stresses which can be relied on for design purposes. The finite element modeling of the OH and MH EC modules has been under constant review since the technique was first applied to these structures. Early verification attempts were based on comparison of finite element deflection predictions with measured module deflections. These comparisons were not entirely successful, due primarily, in the author's opinion, to the difficulty of measuring the actual module deflections with acceptable accuracy. It was proposed in October, 1986, that verification be based on stress, rather than deflection. The purpose of this report is to summarize the results of four experiments which were conducted to determine the accuracy with which ANSYS finite element models could predict the stresses in the OH and MH EC modules as measured by strain gauges. The three comparisons with actual

  3. 3D video

    Lucas, Laurent; Loscos, Céline

    2013-01-01

    While 3D vision has existed for many years, the use of 3D cameras and video-based modeling by the film industry has induced an explosion of interest for 3D acquisition technology, 3D content and 3D displays. As such, 3D video has become one of the new technology trends of this century.The chapters in this book cover a large spectrum of areas connected to 3D video, which are presented both theoretically and technologically, while taking into account both physiological and perceptual aspects. Stepping away from traditional 3D vision, the authors, all currently involved in these areas, provide th

  4. 3D Animation Essentials

    Beane, Andy

    2012-01-01

    The essential fundamentals of 3D animation for aspiring 3D artists 3D is everywhere--video games, movie and television special effects, mobile devices, etc. Many aspiring artists and animators have grown up with 3D and computers, and naturally gravitate to this field as their area of interest. Bringing a blend of studio and classroom experience to offer you thorough coverage of the 3D animation industry, this must-have book shows you what it takes to create compelling and realistic 3D imagery. Serves as the first step to understanding the language of 3D and computer graphics (CG)Covers 3D anim

  5. GaAs-based resonant tunneling diode (RTD) epitaxy on Si for highly sensitive strain gauge applications.

    Li, Jie; Guo, Hao; Liu, Jun; Tang, Jun; Ni, Haiqiao; Shi, Yunbo; Xue, Chenyang; Niu, Zhichuan; Zhang, Wendong; Li, Mifeng; Yu, Ying

    2013-01-01

    As a highly sensitive strain gauge element, GaAs-based resonant tunneling diode (RTD) has already been applied in microelectromechanical system (MEMS) sensors. Due to poor mechanical properties and high cost, GaAs-based material has been limited in applications as the substrate for MEMS. In this work, we present a method to fabricate the GaAs-based RTD on Si substrate. From the experimental results, it can be concluded that the piezoresistive coefficient achieved with this method reached 3.42 × 10-9 m2/N, which is about an order of magnitude higher than the Si-based semiconductor piezoresistors. PMID:23651496

  6. GaAs-based resonant tunneling diode (RTD) epitaxy on Si for highly sensitive strain gauge applications

    Li, Jie; Guo, Hao; Liu, Jun; Tang, Jun; Ni, Haiqiao; Shi, Yunbo; Xue, Chenyang; Niu, Zhichuan; Zhang, Wendong; Li, Mifeng; Yu, Ying

    2013-01-01

    As a highly sensitive strain gauge element, GaAs-based resonant tunneling diode (RTD) has already been applied in microelectromechanical system (MEMS) sensors. Due to poor mechanical properties and high cost, GaAs-based material has been limited in applications as the substrate for MEMS. In this work, we present a method to fabricate the GaAs-based RTD on Si substrate. From the experimental results, it can be concluded that the piezoresistive coefficient achieved with this method reached 3.42...

  7. GaAs-based resonant tunneling diode (RTD) epitaxy on Si for highly sensitive strain gauge applications

    Li, Jie; Guo, Hao; Liu, Jun; Tang, Jun; Ni, Haiqiao; Shi, Yunbo; Xue, Chenyang; Niu, Zhichuan; Zhang, Wendong; Li, Mifeng; Yu, Ying

    2013-05-01

    As a highly sensitive strain gauge element, GaAs-based resonant tunneling diode (RTD) has already been applied in microelectromechanical system (MEMS) sensors. Due to poor mechanical properties and high cost, GaAs-based material has been limited in applications as the substrate for MEMS. In this work, we present a method to fabricate the GaAs-based RTD on Si substrate. From the experimental results, it can be concluded that the piezoresistive coefficient achieved with this method reached 3.42 × 10-9 m2/N, which is about an order of magnitude higher than the Si-based semiconductor piezoresistors.

  8. Some aspects of the compatibility between strain gauge readout equipment and multi-component wind tunnel balances

    Pollock, N.

    1983-07-01

    In multicomponent strain gauge wind tunnel balances it is common to use four arm bridges of gauges arranged to produce an output from one load component and not from other load components which also cause significant strains under the gauges. This system relies on the fact that there is fundamentally one output producing pattern of strains and three nonoutput producing patterns. It is shown that interactions arise between the various strain patterns and that these interactions, and hence the balance calibration equations, are dependent on the nature of the readout equipment used. Specific precautions which must be observed to obtain 0.01% accuracy levels are investigated.

  9. Strain-Gauge Measurement of Weight of Fluid in a Tank

    Figueroa, Jorge; St. Cyr, William; Rahman, Shamim; McVay, Gregory; Van Dyke, David; Mitchell, William; Langford, Lester

    2004-01-01

    A method of determining the amount of fluid in a tank is based on measurement of strains induced in tank supports by the weight of the fluid. Unlike most prior methods, this method is nonintrusive: there is no need to insert instrumentation in the tank and, hence, no need to run wires, cables, or tubes through the tank wall. Also unlike most prior methods, this method is applicable even if the fluid in the tank is at supercritical pressure and temperature, because it does not depend on the presence of a liquid/gas interface (as in liquid-level-measuring methods). The strain gauges used in this method may be of two types: foil and fiber-optic. Four foil gauges (full bridge) are mounted on each of the tank-supporting legs. As the tank is filled or emptied, the deformation in each leg increases or decreases, respectively. Measured deformations of all legs are added to obtain a composite deformation indicative of the change in weight of the tank plus fluid. An initial calibration is performed by recording data at two points (usually, empty and full) for which the mass or weight of fluid is known. It is assumed that the deformations are elastic, so that the line passing through the two points can be used as a calibration curve of mass (or weight) of fluid versus deformation. One or more fiber-optic gauges may be used instead of the foil gauges. The resolution of the fiber-optic and foil gauges is approximately the same, but the fiber-optic gauges are immune to EMI (electromagnetic interference), are linear with respect to temperature over their entire dynamic range (as defined by the behavior of the sample), and measure thermally induced deformations as predictable signals. Conversely, long term testing has demonstrated that the foil gauges exhibit an erratic behavior whenever subjected to direct sun radiation (even if protected with a rubberized cover). Henceforth, for deployment in outdoor conditions, fiber-optic gauges are the only option if one is to rely on the

  10. 混凝土应变计转换系数的测试方法研究%Research on Test Methods of Concrete Strain Gauge Conversion Factor

    钟文斌

    2012-01-01

      建筑工程检测领域常用混凝土应变计检测混凝土的结构应力应变,混凝土应变计的转换系数是影响检测结果准确度的重要参量。本文通过对振弦式应变计和电阻应变片式应变计的结构和检测原理进行分析,分别给出了对应的应变计转换系数测试方法,并列举了部分用到的标准器具%  The concrete strain gauge is used to the concrete stress strain detection in construction engineering. The concrete strain gauge conversion coefficient is an important parameter detection accuracy. This article gives the test methods of corresponding strain gauge conversion coefficient and some standard instruments with analysis of the vibrating wire strain gauge and resistance strain gauge.

  11. EUROPEANA AND 3D

    D. Pletinckx

    2012-09-01

    Full Text Available The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  12. Nuclear safety culture evaluation model based on SSE-CMM

    Safety culture, which is of great significance to establish safety objectives, characterizes level of enterprise safety production and development. Traditional safety culture evaluation models emphasis on thinking and behavior of individual and organization, and pay attention to evaluation results while ignore process. Moreover, determining evaluation indicators lacks objective evidence. A novel multidimensional safety culture evaluation model, which has scientific and completeness, is addressed by building an preliminary mapping between safety culture and SSE-CMM's (Systems Security Engineering Capability Maturity Model) process area and generic practice. The model focuses on enterprise system security engineering process evaluation and provides new ideas and scientific evidences for the study of safety culture. (authors)

  13. Solid works 3D

    This book explains modeling of solid works 3D and application of 3D CAD/CAM. The contents of this book are outline of modeling such as CAD and 2D and 3D, solid works composition, method of sketch, writing measurement fixing, selecting projection, choosing condition of restriction, practice of sketch, making parts, reforming parts, modeling 3D, revising 3D modeling, using pattern function, modeling necessaries, assembling, floor plan, 3D modeling method, practice floor plans for industrial engineer data aided manufacturing, processing of CAD/CAM interface.

  14. Fabrication of a low density carbon fiber foam and its characterization as a strain gauge

    Claudia C. Luhrs; Daskam, Chris D.; Edwin Gonzalez; Jonathan Phillips

    2014-01-01

    Samples of carbon nano-fiber foam (CFF), essentially a 3D solid mat of intertwined nanofibers of pure carbon, were grown using the Constrained Formation of Fibrous Nanostructures (CoFFiN) process in a steel mold at 550 °C from a palladium particle catalysts exposed to fuel rich mixtures of ethylene and oxygen. The resulting material was studied using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDX), Surface area analysis (BET), and Thermogravimetric Analysis (TGA). Tra...

  15. Open 3D Projects

    Felician ALECU

    2010-01-01

    Full Text Available Many professionals and 3D artists consider Blender as being the best open source solution for 3D computer graphics. The main features are related to modeling, rendering, shading, imaging, compositing, animation, physics and particles and realtime 3D/game creation.

  16. 应变计组的应力应变转换%Stress-strain conversion of strain gauge set

    黄浩

    2014-01-01

    为提高应力应变转换最终应力结果的准确度,根据应力应变转换的一般步骤,分析了其中基准时间选取、无应力计可靠性分析、徐变参数公式拟合、应力增量加载方式和应变计组平衡等关键问题,结果表明:基准时间选取缺少一个科学合理的定量原则;无应力计可靠性分析缺少一个可行的分析评判准则;徐变参数公式拟合应该采用全局优化算法;应力增量加载方式应该采用中点瞬时加载终点结束,得到终点时刻应力的方式;对于应变计组平衡问题,基于概率论将平衡问题转化成最优化问题,提出了最优化平衡法,数学实验结果证明该方法是一种科学合理的平衡方法。%In order to improve the accuracy of the final stress result in stress-strain conversion , we analyze some key problems , including the reference time selection , non-stress gauge reliability , formula fitting of creep parameters , stress increment loading mode , and strain gauge set balance , according to general steps of stress-strain conversion .The analysis results show that the reference time selection lacks a scientific and reasonable quantitative principle, the non-stress strain gauge reliability analysis lacks a feasible evaluation criterion , the formula fitting of creep parameters requires a global optimization algorithm , and the stress increment loading mode requires instantaneous loading at the midpoint and ending at the endpoint .Meanwhile , based on the probability theory , the problem of strain gauge set balance is transformed into an optimization problem , and an optimization balance method is put forward , and proven to be scientific and reasonable through a mathematical experiment .

  17. 3d-3d correspondence revisited

    Chung, Hee-Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-01

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d {N}=2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. We also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  18. ACCURACY OF A 3D VISION SYSTEM FOR INSPECTION

    Carmignato, Simone; Savio, Enrico; De Chiffre, Leonardo

    ABSTRACT. This paper illustrates an experimental method to assess the accuracy of a three-dimensional (3D) vision system for the inspection of complex geometry. The aim is to provide a procedure to evaluate task related measurement uncertainty for virtually any measurement task. The key element of...... purpose to establish traceability. Accuracy performances of optical digitisation systems are assessed on the basis of deviations existing between acquired cloud points and the CMM measurements. To demonstrate the feasibility of the proposed method, the procedure is applied to an industrial case study....

  19. IZDELAVA TISKALNIKA 3D

    Brdnik, Lovro

    2015-01-01

    Diplomsko delo analizira trenutno stanje 3D tiskalnikov na trgu. Prikazan je razvoj in principi delovanja 3D tiskalnikov. Predstavljeni so tipi 3D tiskalnikov, njihove prednosti in slabosti. Podrobneje je predstavljena zgradba in delovanje koračnih motorjev. Opravljene so meritve koračnih motorjev. Opisana je programska oprema za rokovanje s 3D tiskalniki in komponente, ki jih potrebujemo za izdelavo. Diploma se oklepa vprašanja, ali je izdelava 3D tiskalnika bolj ekonomična kot pa naložba v ...

  20. New bridge-circuit-type detector to measure precise resistance change of strain gauge at low temperature and magnetic field

    Ohashi, Masashi; Kishii, Nobuya; Tateno, Shota

    2016-04-01

    We report a new highly accurate and versatile bridge-circuit-type detector that has a simple structure and demonstrates a low degree of error for measurements of thermal expansion and magnetostriction by the strain gauge method. As an example, a commercial physical property measurement system (PPMS) is combined with a compact bridge-circuit box. Thermal expansion and magnetostriction are calculated from the resistance of the bridge and bridge voltage, measured by the operation of a standard PPMS resistivity option. The performance of the new detector is demonstrated by measuring the temperature and magnetic field dependences of the strain to obtain the thermal expansion coefficient and magnetostriction of the single crystals of rare-earth compounds RAl2 (R = Dy, Tb).

  1. A study of some production parameter effects on the resistance-temperature characteristics of thick film strain gauges

    Experiments aimed at investigating the possible factors affecting the temperature performance of thick-film resistors are presented. Particular emphasis is given to the temperature coefficient of resistance (TCR) of thick film strain gauges printed on both alumina and stainless steel substrates. The results confirmed that the resistance versus temperature curve is nearly parabolic, but showed that Tmin, the temperature at which the TCR changes to zero, is largely affected by the choice of resistor and substrate materials and also the thickness of the thick-film resistors. A possible explanation is proposed for the observed relationship between resistor thickness and TCR. Other factors, such as the thickness of the substrates, the choice of conductor materials, and whether single- or double-sided printing of the substrate was employed in fabrication were found to make little difference to the temperature performance of the thick-film resistors. (author)

  2. 3D and Education

    Meulien Ohlmann, Odile

    2013-02-01

    Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?

  3. Measurement uncertainty evaluation of conicity error inspected on CMM

    Wang, Dongxia; Song, Aiguo; Wen, Xiulan; Xu, Youxiong; Qiao, Guifang

    2016-01-01

    The cone is widely used in mechanical design for rotation, centering and fixing. Whether the conicity error can be measured and evaluated accurately will directly influence its assembly accuracy and working performance. According to the new generation geometrical product specification(GPS), the error and its measurement uncertainty should be evaluated together. The mathematical model of the minimum zone conicity error is established and an improved immune evolutionary algorithm(IIEA) is proposed to search for the conicity error. In the IIEA, initial antibodies are firstly generated by using quasi-random sequences and two kinds of affinities are calculated. Then, each antibody clone is generated and they are self-adaptively mutated so as to maintain diversity. Similar antibody is suppressed and new random antibody is generated. Because the mathematical model of conicity error is strongly nonlinear and the input quantities are not independent, it is difficult to use Guide to the expression of uncertainty in the measurement(GUM) method to evaluate measurement uncertainty. Adaptive Monte Carlo method(AMCM) is proposed to estimate measurement uncertainty in which the number of Monte Carlo trials is selected adaptively and the quality of the numerical results is directly controlled. The cone parts was machined on lathe CK6140 and measured on Miracle NC 454 Coordinate Measuring Machine(CMM). The experiment results confirm that the proposed method not only can search for the approximate solution of the minimum zone conicity error(MZCE) rapidly and precisely, but also can evaluate measurement uncertainty and give control variables with an expected numerical tolerance. The conicity errors computed by the proposed method are 20%-40% less than those computed by NC454 CMM software and the evaluation accuracy improves significantly.

  4. Study on the use of strain gauge in the electrical test%电测实验中应变片使用问题的探讨

    高瑞杰

    2015-01-01

    Based on the use of strain gauges during strain measurement in the field of mechanical engineering,the feasible measures were put for-ward from the choice and stickup skills of strain gauges perspective. The application process was particularly elaborated combined with the specif-ic methods of strain gauge,which can provide definite reference for the right use of strain gauges in electrical test.%针对机械工程应变测量中应变片使用的问题进行了研究,从应变片的选择和粘贴方面提出了切实可行的解决措施,并结合工程实验中应变片的具体使用方法对应变片的使用流程进行了详细阐述,可为电测实验中正确使用应变片提供一定的参考。

  5. Reference data for distal blood pressure in healthy elderly and middle-aged individuals measured with the strain gauge technique. Part II: Distal blood pressure after exercise

    Arveschoug, Anne Kirstine; Vammen, Birthe; Yoshinaka, Emmy;

    2008-01-01

    on age. Material and methods. DBP after exercise was measured using the strain-gauge technique on individuals in two groups: group I comprising 25 healthy persons aged between 61 and 82 years, and group II 14 healthy persons aged between 45 and 58 years. Strict rules of inclusion were followed...

  6. [Good agricultural practice (GAP) of Chinese materia medica (CMM) for ten years: achievements, problems and proposals].

    Guo, Lan-Ping; Zhang, Yan; Zhu, Shou-Dong; Wang, Gui-Hua; Wang, Xiu; Zhang, Xiao-Bo; Chen, Mei-Lan; He, Ya-Li; Han, Bang-Xing; Chen, Nai-Fu; Huang, Lu-Qi

    2014-04-01

    This paper aims to summarize the achievements during the implementation process of good agricultural practice (GAP) in Chinese Materia Medica (CMM), and on basis of analyzing the existing problems of GAP, to propose further implementation of GAP in TCM growing. Since the launch of GAP in CMM growing ten years ago, it has acquired great achievements, including: (1) The promulgation of a series of measures for the administration of the GAP approval in the CMM growing; (2) The expanded planting area of CMM; (3) The increased awareness of standardized CMM growing among farmers and enterprises; (4) The establishment of GAP implementation bases for CMM growing; (5) The improvement of theory and methodology for CMM growing; (6) The development of a large group of experts and scholars in GAP approval for CMM production. The problems existing in the production include: (1) A deep understanding of GAP and its certification is still needed; (2) The distribution of the certification base is not reasonable; (3) The geo-economics effect and the backward farming practices are thought to be the bottlenecks in the standardization of CMM growing and the scale production of CMM; (4) Low comparative effectiveness limits the development of the GAP; (5) The base of breeding improved variety is blank; (6) The immature of the cultivation technique lead to the risk of production process; (7) The degradation of soil microbial and the continuous cropping obstacle restrict the sustainable development of the GAP base. To further promote the health and orderly GAP in the CMM growing, the authors propose: (1) To change the mode of production; (2) To establish a sound standard system so as to ensure quality products for fair prices; (3) To fully consider the geo-economic culture and vigorously promote the definite cultivating of traditional Chinese medicinal materials; (4) To strengthen the transformation and generalization of basic researches and achievements, in order to provide technical

  7. 3D virtuel udstilling

    Tournay, Bruno; Rüdiger, Bjarne

    2006-01-01

    3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s.......3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s....

  8. Underwater 3D filming

    Roberto Rinaldi

    2014-12-01

    Full Text Available After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space (“Gravity” and the underwater realm look perfect to be reproduced in 3D. “Filming in space” was possible in “Gravity” using special effects and computer graphic. The underwater realm is still difficult to be handled. Underwater filming in 3D was not that easy and effective as filming in 2D, since not long ago. After almost 3 years of research, a French, Austrian and Italian team realized a perfect tool to film underwater, in 3D, without any constrains. This allows filmmakers to bring the audience deep inside an environment where they most probably will never have the chance to be.

  9. 基于CMM-3的软件测试过程模型的研究%Research on Software Testing Models for the CMM Grage 3

    俞磊; 白尚旺; 党伟超; 陆晓丹

    2011-01-01

    Software testing is to ensure the quality of software import measures, while software testing process model is basics of software testing. In this paper, the current popular testing model is studied and analyzed, summarizes the advantages and disadvantages of each model, the CMM-3 levels of theory and ideology are introduced, and in CMM-3 level of software development mode of software testing process model is proposed.%软件测试是保障软件质量的重要措施,而软件测试过程模型是软件测试的基础.首先对当前的测试模型进行了研究和分析,总结了各模型的优缺点,接着阐述CMM-3(Capability Maturity Model,能力成熟度模型,CMM-3,已定义级)的理论思想,最后提出了在CMM-3的软件开发模式下的软件测试过程模型.

  10. Blender 3D cookbook

    Valenza, Enrico

    2015-01-01

    This book is aimed at the professionals that already have good 3D CGI experience with commercial packages and have now decided to try the open source Blender and want to experiment with something more complex than the average tutorials on the web. However, it's also aimed at the intermediate Blender users who simply want to go some steps further.It's taken for granted that you already know how to move inside the Blender interface, that you already have 3D modeling knowledge, and also that of basic 3D modeling and rendering concepts, for example, edge-loops, n-gons, or samples. In any case, it'

  11. 3D Digital Modelling

    Hundebøl, Jesper

    wave of new building information modelling tools demands further investigation, not least because of industry representatives' somewhat coarse parlance: Now the word is spreading -3D digital modelling is nothing less than a revolution, a shift of paradigm, a new alphabet... Research qeustions. Based...... on empirical probes (interviews, observations, written inscriptions) within the Danish construction industry this paper explores the organizational and managerial dynamics of 3D Digital Modelling. The paper intends to - Illustrate how the network of (non-)human actors engaged in the promotion (and arrest) of 3......D Modelling (in Denmark) stabilizes - Examine how 3D Modelling manifests itself in the early design phases of a construction project with a view to discuss the effects hereof for i.a. the management of the building process. Structure. The paper introduces a few, basic methodological concepts...

  12. Professional Papervision3D

    Lively, Michael

    2010-01-01

    Professional Papervision3D describes how Papervision3D works and how real world applications are built, with a clear look at essential topics such as building websites and games, creating virtual tours, and Adobe's Flash 10. Readers learn important techniques through hands-on applications, and build on those skills as the book progresses. The companion website contains all code examples, video step-by-step explanations, and a collada repository.

  13. Estimation of permeability and rock mechanical properties of limestone reservoir rocks under stress conditions by strain gauge

    Iscan, A.G.; Koek, M.V. [Middle East Technical University, Department of Petroleum and Natural Gas Engineering 06531 Inonu Bulvari, Ankara (Turkey); Bagci, A.S. [Institute of Petroleum Engineering, Heriot-Watt University, Edinburg, EH14 4AS (United Kingdom)

    2006-08-15

    Petroleum engineering reservoir parameter calculations are generally performed in the absence of the overburden pressure effect. This leads to serious errors in further development of a hydrocarbon-bearing reservoir. Thus, measurements under stress conditions become important vitally. The objective is to correlate the overburden pressure and the permeability to see the overburden pressure effects on the permeability of Turkish southeastern limestone reservoir rock samples. Stress was applied to four representative limestone samples taken from southeast Turkey. In the laboratory tests, two identical core plugs from every sample were used for each application. This is why a Wheatstone Bridge with a full-bridge strain gauge method was used. A sample is inserted into a load frame and the axial load was increased. Internal friction angles and cohesion factors were determined. An exponential correlation was proposed between permeability and confining pressure. The experimental and correlated results match very accurately. The stress and permeability correlations may be useful with resistivity logs through which permeability may be measured and for stress-strain-related CBL (cement bond logs) which are used for the well bore stability during cementing applications. (author)

  14. Stress analysis of thermal sprayed coatings using a semi-destructive hole-drilling strain gauge method

    Residual stress is an important parameter in coating technology since it often relates to the maximum coating thickness which can be deposited without spallation, and this applies to coatings produced by different thermal spray and thin film technologies. Indeed, the mechanisms by which residual stress is built up or locked into a coating depends markedly on the deposition process and coating structure (growth structure, phase composition) in the same way too. Methods for determining residual stresses in materials include both destructive and non-destructive methods. This contribution describes semi-destructive hole-drilling strain gauge method modified for measurement of residual stresses in thermal sprayed coatings. This method of stress analysis was used for determination of stress levels in thermal sprayed WC-17% Co coatings onto 13% Cr steel substrates. Results show that deposition conditions and final coating structure influence directly the residual stress level in the coatings. It is proved that semi-destructive hole-tube drilling measurement is effective reproducible method of coating stress analysis and good solution for optimization of deposition process

  15. New compliant strain gauges for self-sensing dynamic deformation of flapping wings on miniature air vehicles

    Wissman, James; Perez-Rosado, Ariel; Edgerton, Alex; Levi, Benjamin M.; Karakas, Zeynep N.; Kujawski, Mark; Philipps, Alyssa; Papavizas, Nicholas; Fallon, Danielle; Bruck, Hugh A.; Smela, Elisabeth

    2013-08-01

    Over the past several years there has been an increasing interest in the development of miniature air vehicles (MAVs) with flapping wings. To allow these MAVs to adjust to changes in wind direction and to maximize their efficiency, it is desirable to monitor the deformation of the wing during flight. This paper presents a step in this direction, demonstrating the measurement of strain on the surface of the wing using minimally invasive compliant piezoresistive sensors. The strain gauges consisted of latex mixed with electrically conducting exfoliated graphite, and they were applied by spray coating. To calibrate the gauges, both static and dynamic testing up to 10 Hz were performed using cantilever structures. In tension the static sensitivity was a linear 0.4 Ω μɛ-1 and the gauge factor was 28; in compression, the gauge factor was -5. Although sensitivities in tension and compression differed by a factor of almost six, this was not reflected in the dynamic data, which followed the strain reversibly with little distortion. There was no attenuation with frequency, indicating a sufficiently small time constant for this application. The gauges were thin, compliant, and light enough to measure, without interference, deformations due to shape changes of the flexible wing associated with generating lift and thrust. During flapping the resistance closely tracked the generated thrust, measured on a test stand, with both signals tracing figure-8 loops as a function of wing position throughout each cycle.

  16. A comparison of methods for calibration and use of multi-component strain gauge wind tunnel balances

    Galway, R. D.

    1980-03-01

    A method is presented for calibration of strain-gauge balances which does not require that the components can be loaded independently. Applicable to both 'internal' and 'external' types of balance, the procedure uses a single varying calibration load to determine all linear and non-linear calibration coefficients. Constant 'secondary' loads on one or more components are unnecessary, although they may be used if desired. The usual iterative solution of the second order balance equations is outlined, and an approximate non-iterative scheme is included for completeness, though not recommended. Two methods of accounting for dependency of the calibration coefficients on the signs of the component loads are presented. A concept of 'buoyancy' is introduced to simplify the application of force balance tares, and a procedure for determining the component outputs for absolute zero load (the 'buoyant' offsets) is given. Balance data at a series of model attitudes are used to define these offsets, and also the coefficients in the equations defining the component load distribution of the tare weight at any attitude. The topics covered are ideally suited to formulation and solution by matrix methods, which have been used throughout.

  17. New compliant strain gauges for self-sensing dynamic deformation of flapping wings on miniature air vehicles

    Over the past several years there has been an increasing interest in the development of miniature air vehicles (MAVs) with flapping wings. To allow these MAVs to adjust to changes in wind direction and to maximize their efficiency, it is desirable to monitor the deformation of the wing during flight. This paper presents a step in this direction, demonstrating the measurement of strain on the surface of the wing using minimally invasive compliant piezoresistive sensors. The strain gauges consisted of latex mixed with electrically conducting exfoliated graphite, and they were applied by spray coating. To calibrate the gauges, both static and dynamic testing up to 10 Hz were performed using cantilever structures. In tension the static sensitivity was a linear 0.4 Ω με−1 and the gauge factor was 28; in compression, the gauge factor was −5. Although sensitivities in tension and compression differed by a factor of almost six, this was not reflected in the dynamic data, which followed the strain reversibly with little distortion. There was no attenuation with frequency, indicating a sufficiently small time constant for this application. The gauges were thin, compliant, and light enough to measure, without interference, deformations due to shape changes of the flexible wing associated with generating lift and thrust. During flapping the resistance closely tracked the generated thrust, measured on a test stand, with both signals tracing figure-8 loops as a function of wing position throughout each cycle. (paper)

  18. 3D Spectroscopic Instrumentation

    Bershady, Matthew A

    2009-01-01

    In this Chapter we review the challenges of, and opportunities for, 3D spectroscopy, and how these have lead to new and different approaches to sampling astronomical information. We describe and categorize existing instruments on 4m and 10m telescopes. Our primary focus is on grating-dispersed spectrographs. We discuss how to optimize dispersive elements, such as VPH gratings, to achieve adequate spectral resolution, high throughput, and efficient data packing to maximize spatial sampling for 3D spectroscopy. We review and compare the various coupling methods that make these spectrographs ``3D,'' including fibers, lenslets, slicers, and filtered multi-slits. We also describe Fabry-Perot and spatial-heterodyne interferometers, pointing out their advantages as field-widened systems relative to conventional, grating-dispersed spectrographs. We explore the parameter space all these instruments sample, highlighting regimes open for exploitation. Present instruments provide a foil for future development. We give an...

  19. 3D Projection Installations

    Halskov, Kim; Johansen, Stine Liv; Bach Mikkelsen, Michelle

    2014-01-01

    Three-dimensional projection installations are particular kinds of augmented spaces in which a digital 3-D model is projected onto a physical three-dimensional object, thereby fusing the digital content and the physical object. Based on interaction design research and media studies, this article...... contributes to the understanding of the distinctive characteristics of such a new medium, and identifies three strategies for designing 3-D projection installations: establishing space; interplay between the digital and the physical; and transformation of materiality. The principal empirical case, From...... Fingerplan to Loop City, is a 3-D projection installation presenting the history and future of city planning for the Copenhagen area in Denmark. The installation was presented as part of the 12th Architecture Biennale in Venice in 2010....

  20. Herramientas SIG 3D

    Francisco R. Feito Higueruela

    2010-04-01

    Full Text Available Applications of Geographical Information Systems on several Archeology fields have been increasing during the last years. Recent avances in these technologies make possible to work with more realistic 3D models. In this paper we introduce a new paradigm for this system, the GIS Thetrahedron, in which we define the fundamental elements of GIS, in order to provide a better understanding of their capabilities. At the same time the basic 3D characteristics of some comercial and open source software are described, as well as the application to some samples on archeological researchs

  1. Bootstrapping 3D fermions

    Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran

    2016-03-01

    We study the conformal bootstrap for a 4-point function of fermions in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge C T . We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N . We also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  2. TOWARDS: 3D INTERNET

    Ms. Swapnali R. Ghadge

    2013-01-01

    In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot o...

  3. 3D Dental Scanner

    Kotek, L.

    2015-01-01

    This paper is about 3D scan of plaster dental casts. The main aim of the work is a hardware and software proposition of 3D scan system for scanning of dental casts. There were used camera, projector and rotate table for this scanning system. Surface triangulation was used, taking benefits of projections of structured light on object, which is being scanned. The rotate table is controlled by PC. The camera, projector and rotate table are synchronized by PC. Controlling of stepper motor is prov...

  4. Interaktiv 3D design

    Villaume, René Domine; Ørstrup, Finn Rude

    2002-01-01

    Projektet undersøger potentialet for interaktiv 3D design via Internettet. Arkitekt Jørn Utzons projekt til Espansiva blev udviklet som et byggesystem med det mål, at kunne skabe mangfoldige planmuligheder og mangfoldige facade- og rumudformninger. Systemets bygningskomponenter er digitaliseret som...... 3D elementer og gjort tilgængelige. Via Internettet er det nu muligt at sammenstille og afprøve en uendelig  række bygningstyper som  systemet blev tænkt og udviklet til....

  5. 应变片焊接粘贴一体化装置%The New Strain Gauge Welding and Pasting Integrative Device

    刘晓辉; 颜庆智; 李春宝; 王春辉; 赵晶晶

    2016-01-01

    在电测应力试验中,应变片的焊接与粘贴质量将直接影响到电测结果的准确性。应变片的焊接与粘贴是由试验人员手工操作来完成的,由于在手工粘贴的过程中人为影响因素较大,在粘贴时容易出现应变片位置偏差或者按压不均匀,从而导致获得的数据不够准确。提出并设计了应变片自动焊接粘贴装置,通过该装置可准确、快速地完成应变片的焊接及粘贴。其粘贴质量可靠,节约了粘贴时间,具有较大的经济效益。%The quality of strain gauges pasting directly affects the accuracy of measuring results in experiments of meas-uring stress.Strain gauge is pasting manually by laboratory personnel.The obtained data is inaccurate because of manual paste operation is complex,pasting position difficult to control,and pasting is pressed unevenly.Proposing and designning strain gauge welding and pasting integrative device,it can complete strain gauge welding and pasting accurately and quickly by the device.The pasting quality is reliable.It can also save time and have greater economic benefits.

  6. A kind of strain gauge load cell structure%一种电阻应蛮式称重传感器结构

    张荣轩

    2012-01-01

    本文主要介绍了一种应用在称重式皮带给料机或称重式皮带配料秤产品上的平行梁型电阻应变式称重传感器创新结构。%This article mainly introduces a kind of parallel beam type strain gauge load cell innovation structure which is used in weighing belt feeding machine or weighing belt batch scale productions.

  7. The effect of latency on bone lengthening force and bone mineralization: an investigation using strain gauge mounted on internal distractor device

    Wang Jue; Wu Zhongying; Liu Yaxiong; Li Dichen; Singare Sekou

    2006-01-01

    Abstract Background The purpose of this study was to investigate the effect of latency on the development of bone lengthening force and bone mineralization during mandible distraction osteogenesis. Methods Distraction tensions were investigated at different latency period in 36 rabbits using internal unilateral distractor. Strain gauges were prepared and attached to the distractor to directly assess the level of distraction tension during mandible lengthening. The tensile force environment of...

  8. Ultra-Precision Measurement and Control of Angle Motion in Piezo-Based Platforms Using Strain Gauge Sensors and a Robust Composite Controller

    Zhi-Gang Wu; Da-Li Zhang; Yu-Guang Bai; Lei Liu

    2013-01-01

    The measurement and control strategy of a piezo-based platform by using strain gauge sensors (SGS) and a robust composite controller is investigated in this paper. First, the experimental setup is constructed by using a piezo-based platform, SGS sensors, an AD5435 platform and two voltage amplifiers. Then, the measurement strategy to measure the tip/tilt angles accurately in the order of sub-μrad is presented. A comprehensive composite control strategy design to enhance the tracking accuracy ...

  9. Strain-Gauge-based Electronic Scale Experimental System Design%基于应变片的电子秤实验系统设计

    葛东旭; 杜政道

    2014-01-01

    本文介绍了一款基于应变片的数字显示电子秤实验系统的设计和制作,系统由传感器检测电路、检测信号放大电路、检测信号转换电路和显示电路组成。该设计是为了配合传感器相关教学来进行的,注重系统的模块化和输入输出的相对独立性。文中重点介绍了应变片传感器的制作过程和要点,以及针对应变片传感器的电路调试的步骤和要领。%A strain-gauge-based electronic scale experimental system is introduced which is composed of sensor detecting circuit,signal amplifying and conditioning, signal converting and MCU with a LCD displaying modules.The aim of this design is to practice the project-oriented teaching section of strain-gauge sensor.The system is set into several modules with I/Os to enhance the practicing and understanding. The steps and key points to work out a weighting sensor with strain-gauges and load cellare emphasized.

  10. 3D Harmonic Echocardiography:

    M.M. Voormolen

    2007-01-01

    textabstractThree dimensional (3D) echocardiography has recently developed from an experimental technique in the ’90 towards an imaging modality for the daily clinical practice. This dissertation describes the considerations, implementation, validation and clinical application of a unique

  11. Tangible 3D Modelling

    Hejlesen, Aske K.; Ovesen, Nis

    2012-01-01

    This paper presents an experimental approach to teaching 3D modelling techniques in an Industrial Design programme. The approach includes the use of tangible free form models as tools for improving the overall learning. The paper is based on lecturer and student experiences obtained through...

  12. Shaping 3-D boxes

    Stenholt, Rasmus; Madsen, Claus B.

    2011-01-01

    Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data...

  13. Design of a pulse-type strain gauge balance for a long-test-duration hypersonic shock tunnel

    Wang, Y.; Liu, Y.; Jiang, Z.

    2016-01-01

    When the measurement of aerodynamic forces is conducted in a hypersonic shock tunnel, the inertial forces lead to low-frequency vibrations of the model, and its motion cannot be addressed through digital filtering because a sufficient number of cycles cannot be obtained during a tunnel run. This finding implies restrictions on the model size and mass as the natural frequencies are inversely proportional to the length scale of the model. Therefore, the force measurement still has many problems, particularly for large and heavy models. Different structures of a strain gauge balance (SGB) are proposed and designed, and the measurement element is further optimized to overcome the difficulties encountered during the measurement of aerodynamic forces in a shock tunnel. The motivation for this study is to assess the structural performance of the SGB used in a long-test-duration JF12 hypersonic shock tunnel, which has more than 100 ms of test time. Force tests were conducted for a large-scale cone with a 10° semivertex angle and a length of 0.75 m in the JF12 long-test-duration shock tunnel. The finite element method was used for the analysis of the vibrational characteristics of the Model-Balance-Sting System (MBSS) to ensure a sufficient number of cycles, particularly for the axial force signal during a shock tunnel run. The higher-stiffness SGB used in the test shows good performance, wherein the frequency of the MBSS increases because of the stiff construction of the balance. The experimental results are compared with the data obtained in another wind tunnel and exhibit good agreement at M = 7 and α =5°.

  14. Machined and plastic copings in three-element prostheses with different types of implantabutment joints: a strain gauge comparative analysis

    Renato Sussumu Nishioka

    2010-06-01

    Full Text Available OBJECTIVE: Using strain gauge (SG analysis, the aim of this in vitro study was quantify the strain development during the fixation of three-unit screw implant-supported fixed partial dentures, varying the types of implant-abutment joints and the type of prosthetic coping. The hypotheses were that the type of hexagonal connection would generate different microstrains and the type of copings would produce similar microstrains after prosthetic screws had been tightened onto microunit abutments. MATERIALS AND METHODS: Three dental implants with external (EH and internal (IH hexagonal configurations were inserted into two polyurethane blocks. Microunit abutments were screwed onto their respective implant groups, applying a torque of 20 Ncm. Machined Co-Cr copings (M and plastic prosthetic copings (P were screwed onto the abutments, which received standard wax patterns. The wax patterns were cast in Co-Cr alloy (n=5, forming four groups: G1 EH/M; G2 EH/P; G3 IH/M and G4 IH/P. Four SGs were bonded onto the surface of the block tangentially to the implants, SG 1 mesially to implant 1, SG 2 and SG 3 mesially and distally to implant 2, respectively, and SG 4 distally to implant 3. The superstructure's occlusal screws were tightened onto microunit abutments with 10 Ncm torque using a manual torque driver. The magnitude of microstrain on each SG was recorded in units of microstrain (µε. The data were analyzed statistically by ANOVA and Tukey's test (p0.05. The hypotheses were partially accepted. CONCLUSIONS: It was concluded that the type of hexagonal connection and coping presented similar mechanical behavior under tightening conditions.

  15. An Ultrasonic Strain Gauge

    Kersemans, Mathias; Allaer, Klaas; Degrieck, Joris; Van Den Abeele, Koen; Pyl, Lincy; Zastavnik, Filip; Sol, Hugo; Van Paegem, Wim

    2014-01-01

    A method is introduced for the measurements of strain exploiting the interaction between ultrasound waves and characteristics of the insonified specimen. First, the response of obliquely incident harmonic waves to a deterministic surface roughness is utilized. Analysis of backscattered amplitudes in Bragg diffraction geometry then yields a measure for the in-plane strain field by mapping any shift in angular dependency. Secondly, the analysis of the reflection characteristics of normal incide...

  16. Vibration detection characteristics of FBG sensor and resistance strain gauge%FBG传感器和电阻应变仪的振动监测特性

    龚华平; 杨效; 屠于梦; 宋海峰; 董新永

    2013-01-01

    Fiber Bragg grating (FBG) sensor and resistance strain gauge sensor were fixed on the uniform strength beam. Vibration detection characteristics of two kinds of sensors were investigated. The advantage and disadvantage of two kinds of sensors were compared. Vibration was caused by a motor which was fixed at the end of uniform strength beam. The vibration signal in time domain was measured, which was monitored by FBG sensor and resistance strain gauge sensor simultaneously, and the frequency spectrum was analyzed from the vibration curve through FFT. The results show that the vibration graph monitored by FBG sensor is consistent with the vibration graph monitored by resistance strain gauge sensor. But the frequency spectrum monitored by FBG sensor has second harmonic and third harmonic obviously. The frequency spectrum monitored by resistance strain gauge sensor has weak subharmonic. The experiment investigation also indicates that the vibration signal can not be monitored by resistance strain gauge under the electromagnetic interference conditions, but can be monitored by FBG sensor.%  将光纤布拉格光栅(FBG)传感器和电阻应变片固定在等强度梁上,研究了两种传感器的振动监测性能,总结比较了其优缺点。通过固定在等强度梁末端的电机来产生振动,测试了FBG传感器和电阻应变片监测到随时间变化的振动信号,并分析了振动信号经傅里变换(FFT)的频谱图。实验结果表明,FBG传感器和电阻应变片监测到振动信号的时图基本一致,但是FBG传感器监测到振动信号经FFT变换的频谱图出现较明显的二次谐波和三次谐波,电阻应变仪监测到的频谱图出现的谐波较弱。在实验中还观察到,在有电磁干扰情况下,电阻应变仪监测不到振动信号,而FBG传感器正常工作,不受电磁干扰。

  17. 3D animace

    Klusoň, Jindřich

    2010-01-01

    Computer animation has a growing importance and application in the world. With expansion of technologies increases quality of the final animation as well as number of 3D animation software. This thesis is currently mapped animation software for creating animation in film, television industry and video games which are advisable users requirements. Of them were selected according to criteria the best - Autodesk Maya 2011. This animation software is unique with tools for creating special effects...

  18. A method for enabling real-time structural deformation in remote handling control system by utilizing offline simulation results and 3D model morphing

    A full scale physical test facility, DTP2 (Divertor Test Platform 2) has been established in Finland for demonstrating and refining the Remote Handling (RH) equipment designs for ITER. The first prototype RH equipment at DTP2 is the Cassette Multifunctional Mover (CMM) equipped with Second Cassette End Effector (SCEE) delivered to DTP2 in October 2008. The purpose is to prove that CMM/SCEE prototype can be used successfully for the 2nd cassette RH operations. At the end of F4E grant 'DTP2 test facility operation and upgrade preparation', the RH operations of the 2nd cassette were successfully demonstrated to the representatives of Fusion For Energy (F4E). Due to its design, the CMM/SCEE robot has relatively large mechanical flexibilities when the robot carries the nine-ton-weighting 2nd Cassette on the 3.6-m long lever. This leads into a poor absolute accuracy and into the situation where the 3D model, which is used in the control system, does not reflect the actual deformed state of the CMM/SCEE robot. To improve the accuracy, the new method has been developed in order to handle the flexibilities within the control system's virtual environment. The effect of the load on the CMM/SCEE has been measured and minimized in the load compensation model, which is implemented in the control system software. The proposed method accounts for the structural deformations of the robot in the control system through the 3D model morphing by utilizing the finite element method (FEM) analysis for morph targets. This resulted in a considerable improvement of the CMM/SCEE absolute accuracy and the adequacy of the 3D model, which is crucially important in the RH applications, where the visual information of the controlled device in the surrounding environment is limited.

  19. Ants Colony Optimisation of a Measuring Path of Prismatic Parts on a CMM

    Stojadinovic Slavenko M.

    2016-03-01

    Full Text Available This paper presents optimisation of a measuring probe path in inspecting the prismatic parts on a CMM. The optimisation model is based on: (i the mathematical model that establishes an initial collision-free path presented by a set of points, and (ii the solution of Travelling Salesman Problem (TSP obtained with Ant Colony Optimisation (ACO. In order to solve TSP, an ACO algorithm that aims to find the shortest path of ant colony movement (i.e. the optimised path is applied. Then, the optimised path is compared with the measuring path obtained with online programming on CMM ZEISS UMM500 and with the measuring path obtained in the CMM inspection module of Pro/ENGINEER® software. The results of comparing the optimised path with the other two generated paths show that the optimised path is at least 20% shorter than the path obtained by on-line programming on CMM ZEISS UMM500, and at least 10% shorter than the path obtained by using the CMM module in Pro/ENGINEER®.

  20. Massive 3D Supergravity

    Andringa, Roel; de Roo, Mees; Hohm, Olaf; Sezgin, Ergin; Townsend, Paul K

    2009-01-01

    We construct the N=1 three-dimensional supergravity theory with cosmological, Einstein-Hilbert, Lorentz Chern-Simons, and general curvature squared terms. We determine the general supersymmetric configuration, and find a family of supersymmetric adS vacua with the supersymmetric Minkowski vacuum as a limiting case. Linearizing about the Minkowski vacuum, we find three classes of unitary theories; one is the supersymmetric extension of the recently discovered `massive 3D gravity'. Another is a `new topologically massive supergravity' (with no Einstein-Hilbert term) that propagates a single (2,3/2) helicity supermultiplet.

  1. Massive 3D supergravity

    Andringa, Roel; Bergshoeff, Eric A; De Roo, Mees; Hohm, Olaf [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Sezgin, Ergin [George and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Townsend, Paul K, E-mail: E.A.Bergshoeff@rug.n, E-mail: O.Hohm@rug.n, E-mail: sezgin@tamu.ed, E-mail: P.K.Townsend@damtp.cam.ac.u [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2010-01-21

    We construct the N=1 three-dimensional supergravity theory with cosmological, Einstein-Hilbert, Lorentz Chern-Simons, and general curvature squared terms. We determine the general supersymmetric configuration, and find a family of supersymmetric adS vacua with the supersymmetric Minkowski vacuum as a limiting case. Linearizing about the Minkowski vacuum, we find three classes of unitary theories; one is the supersymmetric extension of the recently discovered 'massive 3D gravity'. Another is a 'new topologically massive supergravity' (with no Einstein-Hilbert term) that propagates a single (2,3/2) helicity supermultiplet.

  2. TOWARDS: 3D INTERNET

    Ms. Swapnali R. Ghadge

    2013-08-01

    Full Text Available In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot of discussions. Basically, one can look into this matter from a few different perspectives: visualization and representation of information, and creation and transportation of information, among others. All of them still constitute research challenges, as no products or services are yet available or foreseen for the near future. Nevertheless, one can try to envisage the directions that can be taken towards achieving this goal. People who take part in virtual worlds stay online longer with a heightened level of interest. To take advantage of that interest, diverse businesses and organizations have claimed an early stake in this fast-growing market. They include technology leaders such as IBM, Microsoft, and Cisco, companies such as BMW, Toyota, Circuit City, Coca Cola, and Calvin Klein, and scores of universities, including Harvard, Stanford and Penn State.

  3. DEVELOPMENT OF A TECHNIQUE TO DETERMINE THE 3D ELASTICITY TENSOR OF WOOD AS APPLIED TO DRYING STRESS MODELING

    Aziz Laghdir; Yves Fortin; Carmen Mariella De la Cruz; Hernández, Roger E.

    2008-01-01

    The objective of this study was to develop an accurate and simple method for measuring the engineering coefficients of the 3D elasticity tensor of wood. A method using a semi-ring extensometer (SRE) and a compression specimen (6-specimen technique) is proposed. The SRE is made of a semi-ring stainless steel blade pin-jointed to two aluminum fixing plates, and two resistance strain gauges bonded to the top and bottom faces of the blade at mid-span position. Groups of five matched compression s...

  4. Modelling and Measurement Uncertainty Estimation for Integrated AFM-CMM Instrument

    Hansen, Hans Nørgaard; Bariani, Paolo; De Chiffre, Leonardo

    2005-01-01

    This paper describes modelling of an integrated AFM - CMM instrument, its calibration, and estimation of measurement uncertainty. Positioning errors were seen to limit the instrument performance. Software for off-line stitching of single AFM scans was developed and verified, which allows...... compensation of such errors. A geometrical model of the instrument was produced, describing the interaction between AFM and CMM systematic errors. The model parameters were quantified through calibration, and the model used for establishing an optimised measurement procedure for surface mapping. A maximum...

  5. 机器人指端应变式触觉传感器%The Robotic Fingertip Tactile Sensor Based on Strain-gauge

    戴士杰; 岳宏; 李慨; 李铁军

    2001-01-01

    叙述了机器人指端应变式触觉传感器的原理、分类和发展,介绍几种典型 的机器人指端应变式触觉传感器,同时提出一种新型的机器人指端应变式触觉传 感器,并对其工作原理进行详细说明.在传感器结构设计中采用合理结构,使被 抓物体的横截面尺寸不受弹性薄板薄板尺寸限制;当超过测量范围时,保证金属 薄板不受破坏,同时实现了柔顺抓握.%The principle、classification and development of robotic fin gertip tactile sensor which use strain-gauge is discussed in details. Several typical robotic fingertip tactile sensors based on strain-gaug e is introduced, meanwhile a new kind robotic fingertip tactile sensor based on strain-gauge is presented, and its work principle is explain ed thoroughly.Using proper construction,the size of the object's cros s section,which is grasped bu the gripper, isn't limited by the size o f the taetile thin metal plate; if the object overweight,then the thin metal plate is insured against damage,meauwhile,the more stable and c ompliant grasp can be realized

  6. Combined study of the strain gauge plethysmography and I-125 fibrinogen leg scan in the differentiation of deep vein thrombosis and postphlebitic syndrome

    The fallibility of the clinical diagnosis of deep venous thrombosis (DVT) and postphlebitic syndrome has led to a variety of noninvasive diagnostic modalities, e.g, Doppler ultrasound, plethysmography, and radionuclide phlebography. The purpose of this study is to analyze the value of combined strain gauge plethysmography (SPG) and I-125 fibrinogen leg scanning in the differentiation of DVT and postphlebitic syndrome. Using strain gauge plethysmograph, 600 studies were performed on 502 patients. The maximum venous outflow (MVO) was calculated. An MVO of 20 cm3/100 cm3 of tissue/min or above was considered normal, and MVO of less than 20 cm3 was abnormal. Of those, 150 limbs had I-125 fibrinogen leg scan and venograms. Of 82 normal SPG, when compared with venograms, 75 were normal, five had postphlebitic syndrome, and two had DVT (97.6% true-negative). Sixty-eight legs had positive SPG, 46 of which had DVT (67.6% true-positive), 21 had postphlebitic syndrome (30.9%), and one was normal (1.5% false-positive). When rubber tourniquets were placed lightly on each leg between the strain gauge and the thigh cuff, 12 legs changed from positive SPG to negative SPG; 56 legs only had positive SPG. Forty-six of these had DVT (82.1% true-positive), nine had postphlebitic syndrome, and one was normal. When positive SPG was combined with positive leg scan, the accuracy raised to 95.6% (44 of 46 legs). If the SPG was positive but the leg scan was negative, the possibility of postphlebitic syndrome was most likely (8 of 10, i.e., 80%)

  7. Comparison of the strain-gauging (450-rosettes) with the finite element calculation (FEM) for a prestressed cast-iron pressure vessel (PCPV)

    Tests on a new type of pressure vessel have been performed for quite some time at the Institute of Reactor Development of the Juelich Nuclear Research Center. An important test goal was the comparison between experimental stress analysis (based on strain gauging) and theoretical stress analysis according to the finite element method (FEM). Material stresses were determined in the vessel wall, sealing lips and load-bearing tendons. Since a pressure vessel exhibits a plane state of stress, the principal- and coordinate stresses had to be measured with approx. 110 450-rosettes. (orig./GL)

  8. Design and verification of an ultra-precision 3D-coordinate measuring machine with parallel drives

    Bos, Edwin; Moers, Ton; van Riel, Martijn

    2015-08-01

    An ultra-precision 3D coordinate measuring machine (CMM), the TriNano N100, has been developed. In our design, the workpiece is mounted on a 3D stage, which is driven by three parallel drives that are mutually orthogonal. The linear drives support the 3D stage using vacuum preloaded (VPL) air bearings, whereby each drive determines the position of the 3D stage along one translation direction only. An exactly constrained design results in highly repeatable machine behavior. Furthermore, the machine complies with the Abbé principle over its full measurement range and the application of parallel drives allows for excellent dynamic behavior. The design allows a 3D measurement uncertainty of 100 nanometers in a measurement range of 200 cubic centimeters. Verification measurements using a Gannen XP 3D tactile probing system on a spherical artifact show a standard deviation in single point repeatability of around 2 nm in each direction.

  9. 3D printing for dummies

    Hausman, Kalani Kirk

    2014-01-01

    Get started printing out 3D objects quickly and inexpensively! 3D printing is no longer just a figment of your imagination. This remarkable technology is coming to the masses with the growing availability of 3D printers. 3D printers create 3-dimensional layered models and they allow users to create prototypes that use multiple materials and colors.  This friendly-but-straightforward guide examines each type of 3D printing technology available today and gives artists, entrepreneurs, engineers, and hobbyists insight into the amazing things 3D printing has to offer. You'll discover methods for

  10. 3D monitor

    Szkandera, Jan

    2009-01-01

    Tato bakalářská práce se zabývá návrhem a realizací systému, který umožní obraz scény zobrazovaný na ploše vnímat prostorově. Prostorové vnímání 2D obrazové informace je umožněno jednak stereopromítáním a jednak tím, že se obraz mění v závislosti na poloze pozorovatele. Tato práce se zabývá hlavně druhým z těchto problémů. This Bachelor's thesis goal is to design and realize system, which allows user to perceive 2D visual information as three-dimensional. 3D visual preception of 2D image i...