Résumé
A fracture prediction criterion for brittle materials has been introduced in the POLLUX finite-element code, in order to predict the risk of rupture of ceramic tools during a forging operation. The POLLUX code, developed by INSA (Lyon) especially to simulate forging operations, is presented. The fracture model is based on the weakest link theory and Weibull analysis. Two different criteria were chosen in order to characterise the stress state, considering the tensile normal stresses. Comparison between the simulation results and the analytical calculations, in a simple compression case, enables the validation of the numerical model. Applications are presented, in which the design of ceramic forging tools is realized using the failure prediction software. A run-strategy of the program is proposed in order to improve the design of the forging tools