Robust design of sheet forming process based on dynamic Kriging model

In order to decrease the quality fluctuation in stamping caused by uncertain factors, and to increase the global approximation accuracy of the traditional static metamodel, a robust design approach for stamping forming process based on dynamic Kriging model was proposed, which combined the robust design with the finite element method. The controllable factors of forming were initially designed. Then, the objective values and their variance were obtained by finite element method, and the roust Kriging model was constructed for the stamping forming. In addition, the global optimization algorithm was employed to optimize the current metamodel to find the potential global optimum. During the optimization process, the design of experiment and corresponding metamodel were updated for improving the approximation accuracy around the global optimum until the global optimum was found under the convergence conditions. The optimization strategy was applied into cup forming in NUMISHEET'93, and the results show that the standard deviation was reduced from 0.0122 to 0.0081 after robust optimization. Application of the robust method based on dynamic Kriging model to sheet forming can obtain satisfactory results.