Three-Dimensional Dynamic Explicit Finite Element Analysis of Charpy Impact Test

Abstract

Dynamic explicit finite element (FE) analysis of the Charpy impact test was conducted in this study to investigate the inertial effect on the stress field ahead of the V-notch in a Charpy specimen. The deformation behavior of the Charpy specimen and the constraint effect on the stress field in the plastic zone near the V-notch were numerically simulated using three-dimensional FE analysis, while considering the contact of the specimen with the striker and anvil. The effect of the strain rate on the flow stress and the increase in temperature during impact loading were included in the dynamic analysis. This analysis shows that the impact load exhibits oscillation and the contact stiffness between the specimen and the striker affects the oscillation of the impact load. The analysis was validated by comparison with experimental results obtained using an instrumented Charpy impact testing machine, which measured the impact load and the load point displacement. The oscillation of the load–time curve was recorded. The magnitude and period of the peak inertia load obtained by the FE analysis were almost consistent with the experimental results. The contact stiffness between the specimen and the striker affected the stress field near the V-notch in the specimen. This indicates that the stress field in the Charpy specimen should be analyzed by the dynamic analysis procedure considering the contact stiffness based on the Hertzian contact theory.