Analysis of stretching of sheet metals with hemispherical punch

Abstract The variational formulation applicable to sheet metal forming is derived by considering solution uniqueness and the effect of geometry change. From this variational formulation, a finite element model based on the membrane theory is developed, and the stretching of sheet metals with hemispherical punches is analyzed. Agreement of the computed solutions with experiments was generally good. The examination of the effects of interface friction and of modeling of constitutive relations by computation revealed importance of these parameters in deformation characteristics of punch stretching.