Optimization of loading curve in tube hydroforming process using multilevel response surface

In tube hydroforming، the loading path، that is the relationship between axial feeding and internal fluid pressure، is of important significance. Researchers have employed various optimization approaches to find an optimum loading path. In this research a statistical method based on finite element analysis has been developed. An accurate FEA has been used to simulate the process and to find the response of the process to the loading. The Response Surface Method (RSM) has been used to model the responses from the finite element analysis. The behavior of the process can be predicted using this model. The obtained model then used to optimize the process. Since The RSM model was initially obtained for a predefined domain of variables multilevel optimization was employed to improve the accuracy of the model. The multilevel optimized curve yielded the best thickness uniformity، the result of which are reported.