Ludwik’s Model Parameter Identification for V-Bending Simulations with Ti64 and MS1200

Abstract

Flow curves coming from tensile tests together with constant young modulus are widely used by industry when modelling sheet metal bending processes. Unfortunately this modelization strategy based on previous mentioned variables is not accurate enough and leads to big errors due to the springback of the material. This drawback is even more important when high strength steels are bended. Aiming to reduce the springback errors, Ludwik’s hardening material models under bending deformation have been obtained for a Ti6Al4V alloy and for a MS1200 martensitic ultra high strength steel and their accuracy has been compared to the classical models obtained from tensile tests. First of all, classical Ludwik’s hardening models are obtained from tensile tests. Then, using a V-Bending test and inverse simulation, Ludwik hardening model parameters for bending are calculated using a Von Mises yielding criteria. As a result, a model able to represent the bending behaviour of these two materials more accurately without complex code modifications is achieved.