Far Eastern Scientific Research Institute of Mechanization and Electrification of Agriculture

A photoelastic technique has been employed for investigating the contact stresses generated in powder compaction. The technique permits both qualitative and quantitative estimation of the stresses arising under operating conditions. In simplicity and directness, it is superior to other methods for the experimental investigation of stress distribution. The results obtained have confirmed the existing views on nonuniform stress distribution on the die wall and the upper and lower punches. In addition, they have revealed certain new phenomena, such as a nonuniform decrease of the transverse pressure and friction forces on the die walls in single action compaction, pressure transmission via particle chains, etc.