Optimum pre-form dies in two-stage forging

Since 1980s the problem of manufacturing defect-free parts has been tackled with simulation tools. In this paper, a numerical method for shape optimisation of pre-form dies in a two-stage hot forging is presented. The object of optimisation is to eliminate work-piece defects that may arise during the forging process. A two dimensional finite element code has been developed for the simulation of the mechanical process and prediction of the defects. The material is incompressible and it follows the Norton–Hoff law. To deal with contact constraint, the velocity-projection algorithm is used. The optimisation method is based on a genetic algorithm supported by an elitist strategy. The developed scheme is used to design optimal pre-form dies for two axi-symmetric examples. The objective function is associated with the quality of the final product. Comparing the obtained optimal results with other articles justifies the proposed optimisation method.