Reverse geometric modeling for pre-form shape of prolate ellipsoid before hydro-forming

Abstract

In order to form the needed prolate ellipsoidal shell with higher dimension accuracy, it is essential to develop an optimal pre-form shape before hydro-forming. A group of numerical simulation according to the optimal Latin hypercube design (Opt LHD) was first conducted on the combined prolate ellipsoidal shells, and the mathematical response models of axis lengths were developed. And then based on the adaptive simulated annealing algorithm, the reverse geometric modeling process was carried out and the possible pre-form shapes were given. Finally, an experimental verification was conducted to evaluate the reverse geometric modeling process, and the comparison between reverse design and experimental data was mainly discussed. It is shown that the dimension deviation between experiment and reverse design is less than 1 %. It is also experimentally proved that the needed prolate ellipsoidal shell can be formed by reversely designing an optimal pre-form shell.