Effect of friction on deformation during rolling as revealed by embedded pin technique

The paper investigates the effects of friction on the heterogeneity of defo rmation during rolling through studies using plane strain (2D) and three-di mensional (3D) finite element models designed to simulate the deformation o f the embedded pin inserts during rolling. Redundant work due to friction i s defined as a path function along the arc of contact. Since deformation du ring rolling is profoundly influenced by the amount of redundant work, whic h depends on friction as a path function along the arc of contact, the stud y has focused especially on methods of representing these frictional effect s. The friction studied has been in one of two classes: the coefficient of friction being constant or varying parabolically along the are of contact. The results show that the values of shear stress and normal pressure along the are of contact depend upon the friction profile. The magnitude of these frictional effects is revealed by the through thickness variation of the r elative pin insert displacement. This displacement changes in the 3D model because transverse spread reduces the amount of displacement along the axia l direction. Comparison of the simulations with experimental pin insert sha pes shows close agreement between the predicted and experimental results, w hile revealing the direction of further work needed to provide suitable mec hanics models to interpret experimental pin insert data. MST/4746.