The Control And Prediction Of Springback During The Sheet-metal Stamping Of Advanced High Strength Steel

In recent years, the automotive industry has paid a great deal of attention to weight reduction and fuel consuming reduction. In order to reduce the weight of automotive body parts to reduce fuel consuming and to improve safety and driving stability, high strength steel is widely used in automotive industry.There are great differences between high strength steel and low carbon steel. High strength result in decreasing plasticity, poor formability, and improving yield strength will lead to surface aberration and springback and unstable shape. With the improving of strength, the residual stress increases, which will lead to unstable shape and dimensions. So springback is the most difficult issue for high strength steel stamping.First, the mechanical properties of high strength steel, controlling method for springback and key issues in the simulation of sheet-metal stamping are stated in the paper. And then the FEM model of a U shape part is set up, the effect of thickness, friction coefficient, blank holder force and drawbeads on springback is analyzed. According to the simulation results, setting up reasonable drawbeads is the most effective way to control springback of high strength steel stamping. Finally, the springback of the body rocker panel is controlled effectively through setting up drawbeads according to the simulation results. And the rule of springback and the control method is proved by test. Then it obtains a good result in controlling the springback of other parts by using the research conclusion .By the studied, the rule of springback on the U shape part is discussed by using the finite element method. And drawbeads used to control the springback of body rocker panel are studied. The research results can guide the production of other similar drawing parts in controlling springback.