Study on the Influence of Bending Angle of Multipoint Stretch-Bending of Profiles on Section Distortion of Parts

The ABAQUS finite element simulation software was used to simulate the flexible 3D multipoint stretch-bending (MPSB) forming process of aluminum profiles. The influence of bending angle on the section distortion was investigated. The results show that the type of rectangular section distortion during horizontal bending and vertical bending is different. The bulging rate and the depression rate increase with the increase in horizontal bending angles; when the vertical bending angle is less than 15°, the depression rate of the horizontally curved section is effectively reduced. When is equal to 30°, is less than 15° which can effectively reduce the depression rate caused by horizontal bending to the profile. When is less than 30°, the depression rate which is caused by horizontal bending can be reduced through the vertical bending angle, with 5° than 15°; the vertical bending process changes the distortion pattern of the profile; the depression rate and the bulging rate increase with the increase of the vertical bending angle. Through the support vector regression and selecting the parameter group c = 1.5, = 0.05, the distortion rate of different angles in the common range is further expanded, and the quality control curve is drawn by combining the test results and prediction results which determine the depression rate as 2%, 2.5%, and 3% processing boundary. Using this curve to predict the distortion rate of the profile is instructive in the actual processing.