Numerical optimization on hot forging process of connecting rods based on RSA with experimental verification

Abstract

A new method of optimization on the hot forging tools for connecting rods was developed in this paper by combining response surface analysis (RSA) with finite element method (FEM). The central composite design (CCD) was prepared with three experimental factors and two optimal targets. The experimental factors which are extracted from design dimensions of the hot forging tool involve cavity center distance, cavity rotation angle, and flash thickness. The targets comprise the maximum forming load and tool wear depth, both of which can be obtained from finite element simulations of hot forging processes. Response surface analysis was implemented to establish the relationships between the targets and the factors. According to the simulation results, the S-type region between die cavities that was dominated by three factors has a significant impact on the metal flowing and forming defects during the hot forging process. The steel billet and forging tools were dimensionally redesigned based on the optimal combination of experimental factors. Practice forging and physical experiments were performed to verify the simulation results, and good agreement between experimental value and simulation value was obtained.