Abstract: According to the requirements of three-dimensional stretch bending process and the characteristics of the structural parts of vehicles and high-speed trains, the design of the reconfigurable die for the process of stretch-bending forming is studied. And a new method to correct the shape considering springback compensation using iteratively adjust the die surface is proposed. The die surface is divided into several sections in a discrete way. Each section is treated as a unit body. By the displacement adjustment of the unit body and the rotation of the forming slider, the die-face can be reconstructed. The three-dimensional forming process with the flexible die and the method are verified by finite element simulation and experiment using the complex T-profile. It is confirmed that the calculation method of the rotation angle of forming slider and the displacement of unit body can effectively adjust and compensate on the die surface. The method of iteratively adjustment the die-face can effectively reduce the springback. The maximum deviation using iterative die-face adjustment in finite element simulation decreases form 2.43 mm to 0.63 mm, and the data in experiment decreases from 6.87 mm to 1.03 mm. It suggests that the method has high precision of compensation and can achieve three-dimensional bending precise forming.

Key words: Flexible die, Iterative adjustment, Three-dimensional stretch-bending