Calculation method of spatial configuration of tube billet in roll forming process of a high strength steel drive shaft tube

The accurate calculation of the spatial configuration of the tube billet in roll forming process is the theoretical premise of roll pass design. But the currently existing shape function method for calculating the spatial configuration cannot describe the springback of the tube billet after bending deformation, so it cannot be applied to the accurate calculation of the spatial configuration of high strength steel with large springback. For this reason, this paper derived the formulas for calculating the bending moment of springback, proposed a trajectory function G(X) to describe the deformation path of the points on the neutral layer of the tube billet in forming direction, and finally established a new method which is called trajectory function for calculating spatial configuration of high strength steel. To verify the accuracy of the trajectory function method, the a...120 x 5-mm-high strength steel shaft tube roll forming process was taken as an example in this paper; the spatial configurations in five stages of the breakdown stage were obtained by experimental method, the trajectory function method, and the shape function method respectively. The calculated results of the trajectory function method were compared with those of the shape function method and the experimental method. The comparison shows that the results of the trajectory function method are closer to the experimental ones, and its overall accuracy is higher than that of the shape function method.