中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 6 June 2020 |
（1. Hebei Key Laboratory of Special Delivery Equipment, Yanshan University, Qinhuangdao 066004, China;
2. Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education of China, Yanshan University, Qinhuangdao 066004, China）
Abstract:In order to effectively predict the fracture of AA7075-T6 sheet, the forming limit curves of AA7075-T6 high-strength sheet were drawn according to Morciniak-Kuczyski (M-K) model and Lou-Huh criterion, respectively. The errors between the predicted values of the two theoretical prediction models and experimental values were calculated by error analysis. The forming limit curves were verified by the punch-stretch test to evaluate the prediction accuracy of M-K model and Lou-Huh criterion. The error analysis results show that the mean error of Lou-Huh criterion with the optimal parameters for all tensile specimens is 25.04%, while the mean error of M-K model for all tensile specimens is 74.24%. The prediction accuracy of Lou-Huh criterion in predicting the fracture of AA7075-T6 sheet is higher. The punch-stretch test results show that the forming limit curve drawn by Lou-Huh criterion can effectively predict the fracture of AA7075-T6 sheet, but the prediction accuracy of M-K model is relatively poor.
Key words: ductile fracture criterion; M-K model; forming limit diagram; AA7075-T6 sheet
