Numerical Evaluation of Surface Roughness Influences on Cold Formability of Dual-Phase Steel

Abstract

DP1000 steel sheets with different surface treatments are taken to three-point bending tests to evaluate their damage and fracture behavior. It is found that different surface treatments yield different fracture behaviors. Conventional finite-element (FE) simulation with an uncoupled material model is able to capture the material's response only for the sheets with the perfectly smooth surface condition. A multiscale strategy is introduced to quantitatively include the surface information into the material model. The localization at the microlevel simulation allows adjusting the fracture criterion of the surface elements in the macrolevel simulation. Therefore, a good agreement between FE simulation and experiment is yielded.