Experimental and numerical studies of springback in air v-bending process for cold rolled TRIP steels

In this investigation, attention is focused on the springback behavior of cold rolled transformation induced plasticity (TRIP) steels in air v-bending process. Experimental studies were carried out on the TRIP steels with various thicknesses and the geometric parameters affecting springback were identified. The change in Young's modulus in simple tension is experimentally investigated and by using the experimentally derived Young's modulus, the air v-bending process is simulated by the implicit finite element method (FEM) code Abaqus/Standard using user subroutine USDFLD. It is shown that, for a better accuracy in v-bending, the change in Young's modulus due to plastic deformation should be taken into consideration. In addition, the influence of friction coefficient on springback in the v-bending simulation is also studied.