Abstract
A new method for sheet metal forming which utilizes the strain-rate dependence of flow stress in the viscoplastic material and the friction-hill phenomenon is proposed. In order to assess its applicability, a dynamic compression test of clay specimens is carried out using a drop hammer apparatus, and the contact pressure on the specimen-platen interface is examined. It is concluded that the proposed method is applicable to sheet forming for relatively small articles. Based on experimental and theoretical considerations, a simple method for estimating the maximum pressure generated under any condition is presented. Some applications of' the process to sheet metal forming are shown.
