The effect of metal anisotropy on the shaped-charge performance

In this thesis, both numerical and experimental approaches are used to study the effects of metal anisotropy on warhead performance. In the numerical approach, the anisotropic plastic flow rule is implemented into the hydrocode DEFEL. The theory, along with its application to the problem of shaped-charge jet stability is presented. In the experimental approach, static tests of three types of anisotropic properties are measured. These are the shear coupling effect, the anisotropic flow stress and the anisotropic hardening effect.; By including the generalized Hooke's law, Hill's yield criterion, and the anisotropic flow rule, the DEFEL code is extended to include orthotropic materials. The instability of an orthotropic jet is calculated with this version of the code. The effect of the anisotropic yield strength on the growth of necks is demonstrated.; The experimental study of the plastic shear-coupling effect is implemented here. Shear strains induced by normal compression of anisotropic copper plates are measured. In the flow stress tests, the nature and magnitude of the anisotropy in rotary-forged plates are displayed. The effect of heat treatment on metal anisotropy is also presented. In the anisotropic work-hardening test, tension and compression preload-compression reload tests are carried out to determine the tendency towards anisotropic hardening after preloading. The results show that preloading does introduce anisotropy.