Researching On Stamping Processes Of A Complex Car Panel Component

Stamping, widely applied in the car industry, is a very important manufacturing technology for sheet metal forming. Wrinkle,cracking and spring back are three main defects occurred in production. In the present thesis, the studies have been focused on the analysis for the forming of a complex panel component of Ford. The software DYNAFORM is used because of its advantages for shell forming abilities. The simulation of manufacturing processes is made for all procedures. The possible defects are predicted and analyzed. The proper solutions to remedy different defects are proposed. The present work in stamping research makes the results of simulation and analysis more instructive for the Die tryout process. It provides the reliable support for further application of the analyzing software.Drawing forming is the key process in manufacture of the car body panels. Quality of the drawn parts will affect directly quality of the manufacture in subsequent processes. In the present study, after the simulation of drawing process has been realized with DYNAFORM, the possible causes of defects and the constraint relationship between them have been estimated by analyzing the FLC,thickness distribution and stress distribution through postprocessor. By modifying the blank shape,adjusting the position of the equivalent draw bead and their percentage of locking force, the ways to eliminate or reduce cracking and wrinkle defects have been predicted by simulation. The process quality is then improved by simulation and finally to instruct the design and the modification of the die mould.The measurements of edge contraction and thickness distribution of different sections on a tryout piece have been carried out. Comparison between experiment and simulation results has been realized. Reliability of the simulation results is discussed.The simulations of spring back unloading process and the three subsequent trimming processes are carried out based on the results of the drawing process. The analysis for spring back unloading process is carried out by the sections of view: sections in different positions have been made to observe and analyze the pattern and quantity of spring back by distribution diagram of the total displacement. No section is made for spring back analysis of the trimming process. The analysis and conclusion is made on the whole stamping component: the pattern of spring back,quantity and position of spring back as well as the change in stress distribution have been studied.The spring back in drawing process is more severe than the other processes. Moreover, the quality of drawing forming affects magnificently the spring back. In order to reduce the spring back defect, shape optimization of the initial sheet near the zone of redundant material in stamping has been realized on the platform UG. The optimized model represents better drawing forming quality. The spring back has been reduced but however it cannot be eliminated.