A Study of Stamping Die Design of Autobody Part Using Software Simulation

Abstract

This paper presents a study of stamping die design of car backdoor reinforcement using software simulation. The existing process of stamping die design and manufacturing in the company being observed involves seven to ten trials before getting an acceptable die and therefore increase the cost of dies. By using software, it is expected that the number of trials is reduced as the design is analyzed in advance to identify unwanted defects in stamping process, such as wrinkle, split, and springback and develop a proper die design. The scenario started with comparing a final stamped part with its design. By using 3D scanner, the final part geometry is obtained and compared with the original 3D CAD model to examine the deviation of the part from its original design. The comparison between the final stamped part and the original design shows discrepancies, it is obvious that most probably the design has been modified to prevent stamping defects. Next, the original design is simulated by applying blank holder force of 109.7 kN. The first simulation on the original design part shows that the minimum thickness strain in -14.4% and has strong wrinkle tendency, therefore the design was modified then run a simulation again on this modified design part.  The modification was mainly focus on essential corner radius and increasing blank holder force to 129.2 kN to prevent wrinkle and reduce springback. The second simulation yields a good formability indicated by better forming limit diagram, safety zone, and springback, despite the minimum thickness strain was increased to -19.2%. So, by using software simulation the correct die geometry can be obtained prior to manufacture the dies as to avoid unnecessary cost of modifying the dies during the trial processes.  In addition, the number of trials can be minimized resulted in shorter lead time of producing stamping dies.