An experimental mock-up for the study of steel behaviour at high temperature during phase transformation

Abstract
In most numerical simulations of welding, due to the very short times involved, viscoplastic effects are neglected. However an experimental mock-up developed at INSA has evidenced the possible importance of such effects, which must therefore be incorporated in a more refined description of the material behaviour. This paper presents such a description; an extension of Leblond's model for transformation plasticity, accounting for the dependence of mechanical properties upon strain rate, is proposed. Finite element analyses using elastic-plastic or elastic-viscoplastic constitutive laws are compared with experiments, and it is found that incorporation of viscoplastic effects significantly improves the quality of the agreement between numerical and experimental results.