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Experimental Mechanics

, 45:368 | Cite as

Inertial effects of quartz force transducers embedded in a split Hopkinson pressure bar

  • D. Casem
  • T. Weerasooriya
  • P. Moy
Article

Abstract

An aluminum split Hopkinson pressure bar is instrumented with quartz force transducers and used to test low impedance materials. Two transducers are used, one at the interface between the specimen and the incident bar and the other at the interface between the specimen and the transmitter bar. It is shown that the stress measured by the incident bar gage often contains a substantial acceleration component, i.e., a significant portion of the signal recorded by the gage is due to its own inertia and not representative of the stress within the sample. Attempts are made to actively compensate for this with measurements of the acceleration of the gage. This is done in three ways: (i) by differentiation of the interface velocity, as determined by a standard strain gage analysis; (ii) by a more direct determination of acceleration, using a measurement of the strain gradient within the bar; (iii) by adding a compensation crystal and mass to the gage to remove the inertial component from the output. It is shown that all three techniques successfully mitigate inertial effects.

Key Words

Kolsky Bar materials testing soft materials 

References

  1. 1.
    Graham, R.A.. “Technique for Studying Piezoelectricity Under Transient High Stress Conditions,”Review of Scientific Instruments,32,1308–1313 (1961).CrossRefGoogle Scholar
  2. 2.
    Karnes, C.H. andRipperger, E.A., “Strain Rate Effects in Cold Worked High-purity Aluminum”,Journal of the Mechanics and Physics of Solids,14,75–88 (1966).CrossRefGoogle Scholar
  3. 3.
    Chalupnik, J.D. andRipperger, E.A., “Dynamic Deformation of Metals Under High Hydrostatic Pressure,” EXPERIMENTAL MECHANICS.6,547–554 (1966).CrossRefGoogle Scholar
  4. 4.
    Wasley, R.J., Hoge, K.G., andCast, J.C., “Combined Strain Gauge-Quartz Crystal Instrumented Hopkinson Split Bar,”Review of Scientific Instruments,40,889–894 (1969).CrossRefGoogle Scholar
  5. 5.
    Togami, T.C., Baker, W.E., andForrestal, M.J., “A Split Hopkinson Bar Technique to Evaluate the Performance of Accelerometers,”Journal of Applied Mechanics,63,353–356 (1996).Google Scholar
  6. 6.
    Chen, W., Lu, F., andZhou, B., “A Quartz-crystal-embedded Split Hopkinson Pressure Bar for Soft Materials,” EXPERIMENTAL MECHANICS,40,1–7 (2000).CrossRefzbMATHGoogle Scholar
  7. 7.
    Chen, W., Lu, F., andWinfree, N.A., “Dynamic Compressive Response of Polyurethane Foams of Various Densities,” EXPERIMENTAL MECHANICS,42(1),65–73 (2002).Google Scholar
  8. 8.
    Chen, W., Lu, F., Frew, D.J., andForrestal, M.J., “Dynamic Compression Testing of Soft Materials,”Transaction of the ASME, Journal of Applied Mechanics,69(3),214–223 (2000).Google Scholar
  9. 9.
    Follansbee, P.S. andFrantz, C., “Wave Propagation in the SHPB,”Transactions of the ASME, Journal of Engineering Materials and Technology,105,61–66 (1983).CrossRefGoogle Scholar
  10. 10.
    Lifshitz, J.M., andLeber, H., “Data Processing in the Split Hopkinson Pressure Bar Tests,”International Journal of Impact Engineering,15,723–733 (1994).CrossRefGoogle Scholar
  11. 11.
    Bacon, C., “An Experimental Method for Considering Dispersion and Attenuation in a Viscoelastic Hopkinson Bar,” EXPERIMENTAL MECHANICS.38,242–249 (1998).Google Scholar
  12. 12.
    Gong, J.C., Malvern, L.E., andJenkins, D.A., “Dispersion Investigation in the Split Hopkinson Pressure Bar,”Transactions of the ASME, Journal of Engineering and Material Technology,112,309–314 (1990).CrossRefGoogle Scholar
  13. 13.
    Bickle, L., “The Response of Strain Gages to Longitudinally Sweeping Strain Pulses,” EXPERIMENTAL MECHANICS,10 (8),333–337 (1970).CrossRefGoogle Scholar

Copyright information

© Society for Experimental Mechanics 2005

Authors and Affiliations

  • D. Casem
    • 1
  • T. Weerasooriya
    • 1
  • P. Moy
    • 1
  1. 1.U.S. Army Research Laboratory, AMSRD-WM-TDUSA

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