Dynamic Finite Element Modeling of Fracture in Charpy V-Notch Specimens of Weld Material 72W

Abstract

Abstract Dynamic finite element modeling of the fracture behavior of fatigue-precracked and V-notch Charpy specimens was performed using ABAQUS Explicit. The purpose of this modeling effort was to predict the upper shelf energies of full-size precracked and Charpy V-notch full-size and sub-size specimens based on the upper shelf energy (USE) of precracked specimens. To achieve this end, finite element model prediction of the USE of a precracked Charpy specimen was calibrated to the corresponding experimental data. Based on this calibration, a material model incorporating a stress-strain curve and fracture strain properties was developed for the nuclear reactor pressure vessel 72 material. The calibrated material model was then applied to the modeling of crack extension and propagation for predicting the USE of both full-size and sub-size Charpy precracked and V-notch specimens. Finite element modeling of Charpy V-notch models has not been performed previously using this methodology. It was found that the predicted USE of standard and sub-size specimens in both notched-only and precracked conditions based on the USE of third-size specimens were in reasonable agreement with the corresponding experimental data. However, when full-size precracked USE was used as the calibration point, full-size notched USE matched well, half and third-size precracked USE were within normal scatter and half and third-size notched USE did not acceptably match with the corresponding experimental values.