Damage Prediction in Metal Forming Process Modeling and Optimization: Simplified Approaches

Abstract

Some simplified numerical methods for damage predictions in metal forming process modeling and optimization are presented in this chapter. The incremental approaches including advanced damage models lead to accurate results, but the simulations are tedious and time-consuming. An efficient solving algorithm called inverse approach (IA) allows the fast modeling of forming processes in only one step between the known final part and the initial blank, avoiding the contact treatment and the incremental plastic integration. To improve the stress estimation in the IA, the so-called pseudoinverse approach (PIA) has been developed. Some intermediate configurations are geometrically created and corrected by a free surface method to consider the deformation path, and the plastic integration based on the flow theory is carried out incrementally to consider the loading history. A simplified 3D strain-based damage model is coupled with the plasticity and implemented into a direct scalar integration algorithm of plasticity (without local iterations), which makes the plastic integration very fast and robust even for very large strain increments. These simplified approaches lead to very fast and useful numerical tools in the preliminary design and optimization.