Evaluation of Charpy Impact Test Performance for Advanced High-Strength Steel Sheets Based on a Damage Model

The Charpy impact test performance was experimentally and numerically studied for two advanced high-strength steel sheets (AHSS) TWIP940 and TRIP590 as well as for a high strength grade 340R. Uni-axial simple tension tests were performed to determine their anisotropic properties and strain rate sensitivities along with their hardening behaviour. The high speed strain rate sensitivity of TRIP590 and 340R (rate sensitive) was also characterized to account for high strain rates involved in the Charpy impact test. To evaluate fracture behaviour in the Charpy impact test, a new damage model, including the triaxiality-dependent fracture criterion and the hardening behaviour with stiffness deterioration, was introduced and the model was calibrated based on the simple tension and V-notch tests. The new damage model along with the anisotropic yield function Hill1948 was incorporated into the ABAQUS/Explicit FEM code, which performed reasonably well to predict the impact energy absorbed during the Charpy impact test.