Elastic/crystalline‐viscoplastic finite element analysis of dynamic deformation of sheet metal

Abstract

Describes the development of a dynamic‐explicit type finite‐element formulation based on elastic/crystalline‐viscoplastic theory to predict the dynamic forming limits of sheet metal. Formulates an evolution equation governing all the slip stages of a single crystal, by modifying Pierce and Bassani’s crystalline plasticity models. Interprets precisely the experimentally observed hardening evolution. Takes account of the importance of the strain rate and temperature sensitivity of the material in predicting dynamic plastic instability. Analyses the deformation and strain localization in a rectangular sheet under stretching, in relation to the plane strain assumption, using the numerical results to demonstrate the influences of tension force and temperature on strain localization, and to show the temperature dependence of shear band formation. Demonstrates that the deviation of tension direction from the axis of symmetry of a single crystal causes non‐simultaneous sliding between primary and conjugate slip systems, resulting in S‐shaped non‐symmetrical deformation.