Dynamic Fracture Characteristics of Metallic Materials under Impact Loading

摘要

This study is concerned with the determination of dynamic crack initiation toughnesses(K_(Id)) and dynamic elastic-plastic fracture toughnesses(J_(Id)) of metallic materials at various temperatures, and utiizes Instrumented Charpy Impact Test as an experimental method. In this study dynamic fracture toughnesses are experimentally determined at various temperatures ranging from 20 deg C approx 300 deg C. Because of the inherent dynamic nature of the tests, unique inertia force will develop during impact and exert strong influences to crack initiation energies. The dissipated energies due to the inertia forces are especially recognized to have significant consequences in the dynamic tests. In this study the dissipated energies due to the inertia forces are computed for the proper determination of crack initiation energies and are further utilized to evaluate the dynamic fracture toughnesses.