Abstract: The most advantage of variable blankhoder force is that the blankholder force can be set according to the forming characters of different phases in sheet metal forming, so advantage of the material formability can be taken fully. However, how to design the variable blankhoder force has not been confirmed yet. The feasibility and validity of the answers are not accepted when using a hybrid optimization algorithm to solve constrained problems, which was put forward by Tohata. Accordingly a improved hybrid optimization algorithm is put forward and the improved optimization algorithm can be used to solve the non – linear constrained optimization problems. After integrating the improved hybrid optimization algorithm and a numerical simulation software, a design method of variable blankholder force is put forward, which is to use the optimization theory and numerical simulation to design variable blankholder force. Using this method to design a kind of variable blankholder force to control a ball cylinder cup forming process, the reduction of thickness is reduced dramatically, and quality of part is improved.

Key words: Improved hybrid optimization algorithm, Numerical simulation, Variable blankholder force