Effect of Constitutive Modelling on the Dynamic Development of Shear Bands in Viscoplastic Materials.

摘要

We model the viscoplastic response of a HY-100 steel by a Power law, and flow rules proposed by Litonski, Bodner and Partom, and Johnson and Cook. Each of these flow rules is first calibrated by using the torsional test data at a strain-rate of 3,300 sec(-1). These material models are then used to study the thermomechanical deformations of a block made of the HY-100 steel and undergoing simple shearing deformations at a nominal strain-rate of 5000 sec(-1). A material defect is simulated by assuming a non-uniform initial temperature distribution within the block. Whereas all of the flow rules used predict a rapid drop of the shear stress as a shear band forms, only for the Litonski Law for nonpolar materials, does an unloading elastic wave amanate outwards from the shear bands. Adiabatic shear bands, Viscoplastic materials, Constitutive modelling, Shear properties, Mechanics, Symposia, Litonski Law, Power Law, Bodner-Partom Law, Johnson-Cook Law. (jg)