Load path modelling in single-step deep drawing of rotationally symmetric cups

Abstract

Abstract The reduction of material usage through damage control in metal forming processes provides the potential for cost reduction. The evolution of damage during metal forming processes has been shown to depend on the evolution of equivalent stress, stress triaxiality and the Lode parameter. However, the investigation of stress states does require numerical modelling of the forming process, for example using the Finite Element Method (FEM). From these models, load paths with regard to stresses, strains and temperatures can be extracted. Such load paths represent the evolution of the respective variable during the forming process. To control damage in deep drawing, the prevalent load paths have to be modified. Aside from variation of the process parameters, such as punch velocity, die geometry and temperature, specific process setups can be used to achieve tailored load paths. Numeric simulation of a single-step deep drawing process creates a basis to modify load paths through process variations such as multi-step deep drawing and reverse deep drawing.