Research on the Metal Forming Process of the Muffler Tube Using Finite Element Method

A muffler is an important part used to reduce noise and to purify exhaust gas in cars and heavy equipments. Recently there has been a growing interest in the designing and manufacturing the muffler tube due to the strict environmental regulations. The technique of perforating on the muffler tube has been largely affected by the shear clearance. And considering the concentration of the force around the punch edge, it is essential to reduced it through the punch radius. In this research, finite element analysis has been carried out to predict optimal forming conditions of the muffler tube using DEFORMTM-3D. In analysis, using one-fourth component of the punch and die, metal forming process is simulated and Cockcroft-Latham ductile fracture theory is used. According to the simulation results, when the shear clearance is 0.04mm, the punch radius is 0.05mm and the value of plate holder force is 250KN, the relation of load-stroke for punch is optimized. Also the burr is minimized and optimal shear section is obtained. The simulation results are reflected to the forming process design for the muffler tube.