A material model for aluminium sheet forming at elevated temperatures

Abstract

In order to accurately simulate the deep drawing or stretching of aluminum sheet at elevated\ud temperatures, a model is required that incorporates the temperature and strain-rate dependency of the material.\ud In this paper two models are compared: a phenomenological material model in which the parameters of a\ud Ludwik–Nadai hardening curve and a power law strain-rate influence are made temperature dependent and a\ud physically-based model according to Bergstr¨om. The model incorporates the influence of the temperature on\ud the flow stress and on the hardening rate and includes dynamic recovery aspects. Although both models can be\ud fitted quite well to monotonic tensile tests, large differences appear if strain rate jumps are applied