Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-23T09:12:57.861Z Has data issue: false hasContentIssue false

A Novel Mechanical Method to Measure Shear Strength in Specimens Under Pressure

Published online by Cambridge University Press:  01 February 2011

Juan Pablo Escobedo
Affiliation:
[email protected], Washington State University, Mechanical and Materials Engineering, Spokane and College, Pullman, WA, 99164, United States, 509-335-2436
David Field
Affiliation:
[email protected], Washington State University, Mechanical and Materials Engineering, Spokane and College, Pullman, WA, 99164, United States
David Lassila
Affiliation:
[email protected], Lawrence Livermore National Laboratory, Livermore, Ca, 94550, United States
Mary Leblanc
Affiliation:
[email protected], Lawrence Livermore National Laboratory, Livermore, Ca, 94550, United States
Get access

Abstract

A new experimental apparatus has been developed for performing shear tests on specimens held under moderately high hydrostatic pressures (on the order of 4 GPa). This testing procedure experimentally determines the pressure-dependent shear strength of thin foil specimens. The experiments provide calibration data for models of materials subjected to extreme pressures such as the Steinberg-Guinan hardening model and can assist in model validation for discrete dislocation dynamics simulations, among others. This paper reports the development of the experimental procedures and the results of initial experiments on thin foils of polycrystalline Ta performed under hydrostatic pressures ranging from 1 to 4 GPa. Both yielding and hardening behavior of Ta are observed to be sensitive to the imposed pressure.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Lewandowski, J.L. and Lowhaphandu, P., “Effect of hydrostatic pressure on mechanical behaviour and deformation processing of materials on materials”, Int. Mat. Reviews, v 43, n 4:145187, 1998.Google Scholar
2 Bridgman, PW, “Shearing phenomena at high pressures”, Proc. Am. Acad. Arts Sci. 71: 387460, 1937.Google Scholar
3 Bridgman, P.W. 1935Effects of shearing stresses combined with high hydrostatic pressure“, Phys. Rev. 48: 825847 (1935)Google Scholar
4 Bridgman, PW, “Effects of hydrostatic pressure on the plastic properties of the metals”, Rev. Mod. Phys 17: 314, 1945.Google Scholar
5 Bridgman, PW, “Flow phenomena in heavily stressed metals”, J. Appl. Phys. 8: 328336, 1937.Google Scholar
6 , Hsiung and Lassila, D.H., “Shock-induced deformation twinning and omega transformation in tantalum and tantalum-tungsten alloys,” Acta Mater. 48:48514865, 2000.Google Scholar
7 Söderlind, P. and Moriarty, J.A., “First-principles theory of Ta up to 10 Mbar pressure: Structural and mechanical properties,” Phys. Rev. B 57:1034010350, 1998.Google Scholar
8 , Lassila, “Strength of materials under high pressure”, Report LLNL.Google Scholar
9 Steinberg, DJ, Cochran, SG, Guinan, MWConstitutive model for metals applicable at high strain rate”, J. Appl. Phys. 51: 14981505, 1980.Google Scholar
10 Steinberg, D., Breithaupt, D, Honodel, CWork-hardening and effective viscosity of solid beryllium”, Physica 139 & 140B: 762765 (1986).Google Scholar
11 Weir, S.R., Akella, J., Ruddle, C., Goodwin, T and Siung, L.. “Static strength of Ta and U under ultrahigh pressures.” Phys. Rev. B 57:1125811265, 1998 Google Scholar