Effect of multi-point roller dies on the forming accuracy of profile in flexible 3D stretch bending technology

With the increasing demand for parts with large sizes and complex cross-sectional shapes, the required target shapes are increasingly difficult to meet. In this paper, a flexible 3D stretch bending device has been developed, which can form complex cross-sectional 3D parts with 2 degrees of freedom at one time and can form large sizes 3D parts. Compared with traditional monolithic molds, discrete molds using in flexible 3D stretch bending forming are more convenient for shape adjustment of target profile. The multi-point roller dies are composed of multiple different roller-type die units. In order to better evaluate the forming accuracy of 3D parts, the influence of the number, shape, and surface of the roller dies on the forming results is discussed. The influence of different parameters on the forming accuracy is studied by numerical simulation, and the results are compared with the experimental results. From the perspective of forming accuracy, the influence of FSBR process and different parameters on the forming result is analyzed. Analysis of the dimple and shape errors of the FSBR parts shows that the number, shape, and surface of RDU directly affect the forming accuracy. By modifying the die parameters, the surface dimples can be reduced and the forming accuracy can be improved.