Springback analysis for sheet forming processes by explicit finite elementmethod in conjunction with the orthogonal regression analysis

A new method to evaluate the amount of springback in sheet forming processe s based on the explicit finite element method and the orthogonal regression analysis is presented in this paper. To calculate springback accurately, a simple but effective contact searching algorithm is described and Lagrangi an multiplier method was used to evaluate the contact force. The loading an d unloading process could be simulated within one code. The numerical resul ts by the present method were compared with the results by the commercial d ynamic explicit code LS-DYNA3D, also with the experimental results and very good agreement was drawn. In order to obtain the springback conveniently f or the purpose of practical use, the orthogonal regression analysis was imp lemented to establish the explicit relationship between the springback and some design parameters. The present method has been applied to the analysis of some actual sheet forming processes and very good agreement between the numerical results and the experimental results in the final geometry was o btained. (C) 1999 Elsevier Science Ltd. All rights reserved.