Finite element simulations of shear localization in plate impact

• Published in: Journal of the mechanics and physics of solids 1994-03, Vol.42 (3), p.423-458
• Main Authors: Zhou, M., Needleman, A., Clifton, R.J.
• Format: Article
• Language: English
• Subjects: Applied sciences; Elasticity. Plasticity; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Physics; Solid mechanics; Structural and continuum mechanics; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Vibrations and mechanical waves
• ISSN: 0022-5096
• DOI: 10.1016/0022-5096(94)90026-4

S hear band development in a tungsten heavy alloy (WHA) during pressure-shear plate impact is analysed numerically. The alloy has a microstructure of hard tungsten grains embedded in a soft alloy matrix. A two-dimensional, plane strain model of the alloy microstructure is used in the computations. For this model microstructure a fully coupled thermo-mechanical initial boundary value problem is formulated and solved, accounting for finite deformations, inertia, heat conduction, thermal softening, strain hardening and strain-rate hardening. Calculations are carried out for distributions of uniform grains and for micro-structures obtained from digitized micrographs of the actual alloy. The effects of variations in grain volume fraction and grain size are considered. Experiments and the numerical calculations show that the two phase alloy is more susceptible to shear banding than either of the constituent phases. While the onset of shear localization depends on the grain distribution and volume fraction, the shear band width is found to be set by heat conduction and is insensitive to the grain volume fraction and the grain morphology, The shear band width obtained from the calculations is in good agreement with what is observed in the experiments. Furthermore, the computed shapes of the deformed tungsten grains inside the band resemble closely the observed shapes of the deformed grains in the experiments.