Design And Development Of Pre-process System For Complete Process Forming Simulation Of Automobile Panel

Finite element simulation technology for sheet metal forming has been widely used in the forming of automobile panel in recent years. The numerical simulation technology for sheet metal forming is mostly used for single process simulation currently, while the simulation of automobile panel forming is a typical simulation for multi-operation. Although it can be predicted design flaws of the process by the simulation for single process, it cannot be forecasted the problems which are appeared in the entire stamping process. For the simulation for the automobile panel forming, a simulation system for complete process based on the actual process is required, which can truly simulate the whole processes for the automobile panel forming.This research is supported by NSF named:"The Independent Research of High-speed Simulation and Optimal Process Design aiming at the Formability of Automobile Panel"(NO.50575080) and National 863 Program:"The Formability and Optimal Process Design Based on the Simulation of Automobile Parts"(NO. 2006AA04Z140). This paper mainly focus on the characteristics of process for automobile panel forming, the author has developed a complete process simulation pre-process system, which is a significant entire process for the automobile panel forming.Based on the characteristics of automobile panel, the function and demands of the pre-process system is analyzed particularly, design idea of the system in which process is the core is presented, and the frame, data structure and data flow diagram of the system is studied on basis of Object-oriented design method. Based on the theory and the system design, a complete process simulation pre-process system for the automobile panel is developed, by which all processes of automobile panel can be simulated, which include gravity, closing, forming, drawing, trimming, flanging and springback.Some key technologies of the pre-process system are studied in this paper. The criteria of mesh generation of blank based on the fillet and mesh adaptive level is established. The automatic adjustment for the element normal vector based on the boundary-dependent algorithm is implemented. The concept of virtual blank is presented, and the automatic measure algorithm of tools elements is improved, which solves the problem of tools automatic assembly for complete process, further the tools assembly of the entire process and the interfere between the tools are checked by the animation, finally the multi-language version of the system is implemented by resource DLL and multi-language initial file.The actual stamping parts: car floor, car fender and air-condition fin is chose in this paper, it indicate that the pre-process system can provide accurate finite element model and processing parameters for the complete process simulation of automobile panel by the simulation of these parts. By testing numerous examples, it show that the pre-process system has reached the level of industrial utility, in which there is the characteristics of simple, powerful and stable performance. The system has been applied to many domestic enterprises and provides the guidance to actual production.