A NOVEL METHOD FOR MEASURING AND CHARACTERIZING DYNAMIC FRACTURE- INITIATION TOUGHNESS OF ELASTIC-PLASTIC MATERIALS

摘要

The characterization and testing methods of the dynamic fracture initiation toughness of elas- tic-plastic materials under tensile impact are studied. By using the self-designed bar-bar tensile impact appa- ratus, a novel test method for studying dynamic fracture-initiation ahs been proposed based on the one-di- mensional test principle. The curve of average load v. s. displacement (P-δ) is smooth until unstable crack propagation, and the kinetic energy which does not contribute to the crack growth can be removed from total work done by external-force to the specimen.