Elastic behaviour characterisation of TRIP 700 steel by means of loading-unloading tests

The elastic behaviour of TRIP 700 steel under plastic deformation is analysed. The analysis is carried out by means of classical tensile test and loading-unloading cyclic tests. These tests have been performed using high deformation strain gages, which enable an accurate and continuous measurement of strain. An elastic modulus reduction of 20% is observed for 12% plastic deformation. Furthermore, non-linear unloading and loading paths have been found in this work. This is an important difference with respect to other authors and opens new possibilities for the development of new material models to improve the prediction of the post-forming springback of industrial parts, which is an important issue for the automotive industry. (C) 2015 Elsevier B.V. All rights reserved.