In order to grasp the springback rule of TRB ( tailor rolled blank ) parts after forming , the springback behavior of TRB was investigated by integrating such three means as theoretical research , numerical simulation and stamping experiments.Fundamental theories of springback were analyzed.The stamping and springback processes of annealed 1.2 / 2.0mm TRB , 1.2mm and 2.0mm plates for U-channel were simulated , and the simulation results were compared with the experiments.The results indicate that the springback of TRB falls in between those of the 1.2mm and 2.0mm plates.It is desirable for the TRB U-channel to have die clearance of 1.1times maximum blank thickness and friction coefficient of about 0.12 , and longer thickness transition zone is preferable.The simulation data demonstrate reasonably good agreement with the experiments.
ZHANG Hua-wei 1 , LIU Li-zhong 1 , HU Ping 1 , LIU Xiang-hua 2 ( 1.Faculty of Vehicle Engineering and Mechanics , State Key Laboratory of Structural Analysis for Industrial Equipment , Dalian University of Technology , Dalian 116024 , Liaoning , China
Residual stress developed during the rolling process of tailor rolled blank （TRB） can affect the springback of finished parts considerably. Springback characteristics of unannealed and annealed TRBs were investigated by means of numerical simulation and experiments taking U-Channel as an example. TRBs were annealed by the annealing process （700 ℃, holding time 10 h）, then stamping and springback processes of unannealed and annealed TRBs were simulated, and corresponding experiments were also carried out. Effects of the transition zone length, the blank thickness, the friction coefficient and the die clearance on the springback of TRB were analyzed. The results demonstrate that the springback of TRB annealed at 700 ~C for 10 h re- duces significantly. For unannealed and annealed U-Channels, the springback of TRB U-Channel is in direct proportion to the die clearance and is in inverse proportion to the transition zone length, the blank thickness and the friction coefficient. Spring- backs of the thinner monolithic （uniform thickness） blank, the thinner side of TRB, the thicker side of TRB and the thicker monolithic blank are sorted in descending order.
