DYNAMIC SHEAR BANDING - A 3-DIMENSIONAL ANALYSIS

The three-dimensional (3D) aspects of localized deformations and shear banding under dynamic loading conditions and in both elastoviscoplastic and thermoviscoplastic materials are investigated. It is shown that the rate-dependent constitutive models considered that exhibit a net softening response, along with standard eight-node brick finite elements with one integration point (piece-wise constant strain and stress fields), produce sharp localized deformation zones without recourse to any special mesh design. This, in turn, allows for the numerical prediction of the shear band angle. The 3D results are illustrated for the development of shear bands in uniaxial extension of specimens with different thicknesses. It is shown that the 3D geometric aspects have considerable effects on the development of the shear band and its evolution. By examining the behavior of the kinetic energy, a localization criterion is also developed.