Forging preform design using a reverse simulation approach with the upper bound finite element procedure

Abstract

Forging preform design, which is a critical step when making forging products, is still performed by experience-based methods or trial-and-error approaches with or without computer simulations. To improve this time consuming task and to establish a systematic forging design method, a reverse simulation approach is proposed. The reverse simulation starts from the finished shape, with boundary areas being released as dies are moved backwards. The simulation is based on the upper bound method with the finite element procedure being used to find a velocity field representing the minimum energy required for plastic deformation. A measure of the material distribution is proposed to evaluate the complexity of the shape, which aims to ensure that the reversed shape becomes a simple geometry. The control of the boundary conditions, i.e. a strategy of releasing contact areas, is also presented. Forward simulations performed by a validated commercial modelling package are used to assess the predicted preform. The results demonstrate that the proposed approach has a considerable potential in the preform design for the forging industry.