Theoretical and experimental investigation of hydro-mechanical deep drawing of hemi-prolate spheroid cups

Abstract

In this paper, a theoretical model was proposed to stress analysis and calculate the critical fluid pressure path corresponding to rupture instability in hydro-mechanical deep drawing (HMDD) of hemi-prolate spheroid (HPS) cups. This model is based on Barlat and Lian yield criterion and maximum drawing force condition was utilized to rupture instability analysis. The effects of material and process parameters were investigated on critical fluid pressure path. The results demonstrated that maximum permissible fluid pressure is increased by enhancement of sheet thickness, strain hardening exponent, anisotropy and reduction of friction coefficient. Decrease the difference between semi-major and semi-minor axis of the hemi-prolate spheroid, enlarges safe zone. Finally, a serial of HMDD experiments were accomplished to verify the theoretical critical fluid pressure path. Theoretical results agree well with experimental data.