Dynamic finite element analysis of precracked, notched and layered Charpy impact tests.

摘要

Finite element modeling of Charpy impact specimens was performed for fission reactor pressure vessel materials and fusion reactor first wall materials as follows: Dynamic finite element modeling of the fracture behavior of fatigue-precracked Charpy specimens and Charpy V-notch specimens made up of pressure vessel steels in both unirradiated and irradiated conditions was performed using ABAQUS Explicit. Predictions of the upper shelf energy of standard (full-size) Charpy specimens were calibrated using existing upper shelf energy data. Using a tensile fracture-strain based method for modeling crack extension and propagation, the calibrated material properties were used in standard and subsize Charpy V-notch models. It was found that the predicted upper shelf energies of standard and subsize specimens were in reasonable agreement with experimental data.; Finite element modeling of crack extension under impact was also performed to study the suitability of layered composite structures in plasma facing and primary wall structures of fusion reactors. Dynamic crack extension and propagation are affected by the layer orientation, interfacial properties, and material properties of the layered structure. By making the proper choices in these variables, the energy at the crack tip can be dissipated in a larger volume of material or spent along the interface resulting in only partial fracture of the structure.