Study On Springback Rules Of Long Range Flanging Process Of High Strength Steel

Seat slide rail of the vehicles car is one of a key parts of automobile seat assembly. The seatrail has long working stroke, heavy load and small design space. The forming process of theworking face of seat slide rail is a typical straight flanging process with short straight edge and longlength. Due to the elasticity recovery after unloading, the shape and size of workpiece woulddeviate from that of die surface. Therefore, the Bauschinger effect of the high strength steel rendersdifficulty to prediction of springback of the metal forming process.The springback has great influence to the forming precision of the workpiece that would posedifficulty to the consequent assembly process of the seat. The springback mechanism in the straightflanging forming process was focused which were studied by using the finite element simulationmethod and experiment way. Also, the kinematic hardening model of Yoshida-Uemori and isotropichardening materials model of Hill（1948）Yield Criterion was studied to simulate the Bauschingereffect of the high strength steel. The research has very important theoretical significance andpractical value on improving prediction accuracy of springback and deepening understanding of themechanism of the springback in flanging forming process.The Yoshida-Uemori model of the high strength steel DP780was studied and the parameters ofthe model were obtained. The parameters sensitiveness to the prediction precision of the springbackwas obtained based on the orthogonal simulation test. The key simulation techniques were studiedin order to improve the simulation precision.The straight flanging process was studied and an evaluation method was proposed. Theinfluence rules of the metal forming process parameters toward springback were obtained by usingnumerical simulation method and consequently experiment way. Comparison between numericalsimulation data and experimental results were performed and these two match well.