Finite element method-based modeling of bending under tension friction test of deep drawing quality steel sheets

Understanding of the effect of the friction on the sheet deformation is a key factor in design and realization of stamping process. Among others, bending under tension friction test simulates the frictional phenomena on rounded edge of punch in sheet metal forming operations. In this paper, change of friction coefficient with 1-mm-thick deep drawing quality steel sheet deformation was evaluated using a special tribological simulator which simulates the friction in rounded edge of punch. The results of experimental investigations have been used to verify the results of numerical modeling carried out in MSC.Marc 2014 program. The friction coefficient value and contact stresses have been determined numerically. The results show that the distribution of the normal and friction stresses is very non-uniform along the wrap angle of the cylindrical countersample and along the specimen width. It has been concluded that FEM-based investigations allow a fast and suitable selection of the punch edge profile ensuring an increase of maximum allowable sheet strains.