Investigations of thickness distribution in hole expanding of thin steel sheets

This work aims to investigate the effect of punch geometry on the sheet thickness distribution in the collar formed during hole-flanging process. Three different punch geometries: cylindrical (flat-bottomed), hemispherical and conical were used in the experiment as well as in numerical simulation. Extra deep drawing quality (EDQ) steel sheet with a thickness of 1.0 mm was selected for this work. The results of experimental investigations were compared with the results of numerical modeling performed using the FE based MSC.Marc +MENTAT computer code.