Numerical Simulation On Forming And Springback Compensation Of The Automobile Backdoor Inner Plate

The body is an important part of the car, it affects the beautiful degree of the car, and the quality of automobile panel determines the body quality, which promoted people to improve the quality of automobile panel through continuous exploration and research, but also make the automobile theorical study and forming process continued to deepen. However, most of the automobile panels are complex three-dimensional surface structure, the forming quality requirement is high, the cause of the effct in the process of stamping forming quality is complicated, and the law is not easy to grasp, it is difficult to determine various process parameters in the process of mold design. In the design process,designers have to depend heavily on the design experience. It not only can not guarantee the quality of the products, but also to extend the product development cycle,increase the cost of the research, hinder the development of new models.With the continous development of CAD/CAE/CAM technology, numerical simulation technology has been widely used in the design and manufacture of automobile panels. Through the numerical simulation technology, we can analyze the distribution of stress and strain in the process of stamping, to avoid wrinking,cracking, and excessive springback and other defects in forming process. The application of simulation technology, can verify the possibility of forming before the mold is producted, by optimizing the structure and technological parameters to improve the forming quality, so as to achieve the purpose of reducing production cost and shorten the development cycle.This paper systematically analyzed the theory of finite element simulation of sheet metal forming, involved the key facts in the process of numercial simulation, such as yield criterion, unit type and its selection, the algorithm of finit element control equation, contact treatment and so on. According to the quality requirements of automobile panel forming and characteristics, for may occur in the process of stamping forming defects such as crack,wrinkle and springback, from the aspects of material model, mold clearance, drawbead, addendum surface, friction coeffcient and blank holder force are analyzed in detail. In this paper, taking the automobile backdoor inner plate as the research object, first established the CAD model, added the process faces and designed the binder, set up the reasonable parameters, using sheet metal stamping forming numerical simulation software Auto Form to compute the parts drawing, trimming, flanging shaping process, and compared with the actual stamping parts, in order to verify the rationality of the mould and process design. Introduces the influence factors of srpingback and the method to control springback, springback simulation was carried out on the automobile backdoor inner plate, predict the springback amount, according to the principle of geometric compensation method, optimize the mold surface of each step, and to calculate again. By comparing the surface before and after sprinback with the actual puoduct suface, verify the rationality of the mold surface optimization.