A new optimization method for drawbead in sheet forming process based on plastic forming principles

In order to solve the problem that the existing optimization methods have very low efficiency for drawbead optimization of complex automotive panels, a new optimization method for drawbead in sheet forming process is proposed based on plastic forming principles. Essentially different from the existing common optimization methods which are on the basis of mathematics or statistics, the optimization method proposed is a professional method on the basis of the plastic forming theory. Plastic forming principles are firstly established to build the relationship between the forming quality and the drawbead restraining force. Then, a forming quality evaluation model in the affected zone of drawbead segments can be established to qualify the forming quality near the drawbead segments based on the principles. Finally, an improved quasi-Newton algorithm with a variable step is introduced to adjust the restraining force of each drawbead segment, which enables the optimal drawbead scheme of complex automotive panels to be obtained in several iterations. In order to verify the practicality of this method, a numerical experiment of the inner door panel is conducted. The optimization result shows that this method has high efficiency and accuracy, which is of great significance to improving the intelligent level of die design in sheet forming process.