Modelling the hot plane strain compression test Part 1 - Effect of specimen geometry, strain rate, and friction on deformation

摘要

Thermomechanically coupled finite element analysis of the hot plane strain compression test has been carried out to investigate the effect of various test parameters on the measured response and deformation of specimens. The results are presented in a series of papers. In this paper (Part 1), the results of two-dimensional simulations are discussed, evaluating the effects of material type, specimen geometry, strain rate, and friction on the overall deformation behaviour. The effects of spread and friction are detailed in Part 2, and the effects of asymmetry during the test are detailed in Part 3. The present results show that the local deformation behaviour is independent of the type of material and strain rate, at least up to 50 s~(-1). The behaviour, however, depends strongly on friction and initial specimen geometry, with deformation becoming more uniform with decreasing initial specimen thickness, i.e. with increasing tool width w to specimen thickness h ratio. The deformation is constrained within the predicted slip line fields, and is controlled by the instantaneous geometry and not by the strain history. At low values of w/h the strain rate gradients are very high, and the raw data must be corrected for local strain rates and strains. Master curves have been produced to account for these gradients. The present results can be treated as generic, since the deformation is independent of material and the strain rate of deformation.