An equation of state for anisotropic solids under shock loading
Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK
Revised: 7 June 2008
Published online: 30 July 2008
An anisotropic equation of state is proposed for accurate extrapolation of high-pressure shock Hugoniot states to other thermodynamics states for shocked single crystals and polycrystalline alloys. The proposed equation of state represents mathematical and physical generalization of the Mie-Grüneisen equation of state for isotropic material and reduces to this equation in the limit of isotropy. Using an anisotropic nonlinear continuum framework and generalized decomposition of a stress tensor [Int. J. Plasticity 24, 140 (2008)], the shock waves propagation along arbitrary directions in anisotropic solids of any symmetry can be examined. The non-associated strength model includes the distortion effect of the yield surface which can be used to describe the anisotropic strength differential effect. A numerical calculation showed that the general pulse shape, Hugoniot Elastic Limits (HELs), and Hugoniot stress levels for aluminum alloy 7010-T6 agree with the experimental data. The results are presented and discussed, and future studies are outlined.
PACS: 62.50.Ef – Shock wave effects in solids and liquids / 62.20.fq – Plasticity and superplasticity / 47.40.Nm – Shock wave interactions and shock effects
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008