Strength Analysis And Structure Optimization For High Strength Steel Stamping Die

With higher requirements of light weight and safety performance of the car, high strength steel is gradually becoming the preferred material for automobile covering parts. Compared with ordinary steel, High strength steel has the advantages of high strength and low plasticity. It is easier to cause the wear of the die. Therefore, higher requirements are put forward on the structural forms of stamping die. At present,structural design of stamping die depends only on the experience of die-designers,due to the lack of reliable and accurate analysis method; so the elastic deformation of the die is often ignored at design time, it is difficult and inaccurate to obtain the pressure distribution of the die and the forming quality of the sheet metal.Therefore, this paper presents a new structural optimization method, considering the elastic deformation of the die. Structure type of the die is analyzed by combining the topology optimization technology and sheet metal forming numerical technology.First, LS-DYNA is used to build the elastic-plastic finite element model, in order to obtain the force from the sheet to the in the stamping process. The force and deformation of the traditional die were fully and accurately predicted though analyzing the forming limit chart as well as the results of stress and strain in the stamping process.Secondly, through the method of load conversion, contact force in stamping FEM simulation were loaded into the force boundary conditions in the topology optimization model successfully. Then the topology optimization of the stamping die was performed by OPTISTRUCT software. The optimized structure was reconstructed geometrically, combined with the casting performances of automobile panels.Finally, the dynamic analysis results before and after optimizations are analyzed comparably. The results showed the weight of the new structure was reduced by around 26.4%, the maximum stress decreased by 48.3%, the maximum strain decreased by 64.5%. In conclusion, the optimization of die structure is proved to be effective.