An adaptive mesh refinement technique for the analysis of shear bands in plane strain compression of a thermoviscoplastic solid

We have developed an adaptive mesh refinement technique that generates elements such that the integral of the second invariant of the deviatoric strain-rate tensor over an element is nearly the same for all elements in the mesh. It is shown that the finite element meshes so generated are effective in resolving shear bands, which are narrow regions of intense plastic deformation that form in high strain-rate deformation of thermally softening viscoplastic materials. Here we assume that the body is deformed in plane strain compression at a nominal strain-rate of 5000 sec^-1, and model a material defect by introducing a temperature perturbation at the center of the block.