LOADING AND DEFORMATION PROGRESSION DURING OPEN FORGING OF HOLLOW CYLINDRICAL BLANKS

摘要

A solution for a hollow cylindrical blank with a velocity field derived from the equations of equilibrium and compatibility conditions is obtained. The solution, accounts for both platen interfacial friction and the blank geometry. The platens were assumed as flat bodies moving normal to the blank surface. The problem is solved by the upper-bound approach, with the assumption of constant shear factor (average coefficient of friction) between platens and blank. The radius of the blank which does not experience deformation during the forging process is referred to as the neutral radius, and was determined by power minimization. The neutral radius as well as the friction coefficient at the blank interface were found to play an important role in determining the average forging pressure and the blank deformation from initial to final configurations.