Occurrence and numerical prediction of surface defects during flanging of metallic sheets

Surface defects can develop on automotive exterior panels after drawing and flanging steps, dur- ing springback and may alter significantly the vehicle quality. These defects are characterized by a small depth below 0.5 mm and are then difficult to detect numerically. This study focuses on the surface defects for two parts: an industrial upper corner of a front door and a L-shaped part designed on purpose to reproduce at a small scale surface defects that occur after flanging.