CRACK PROPAGATION ANALYSIS OF STATICALLY INDETERMINATE BEAM BY ELASTIC-PLASTIC FRACTURE MECHANICS

摘要

This paper develops an analytical model for the plastic collapse of a statically indeterminate rectangular beam containing a crack. Limit analysis, elastic-plastic fracture mechanics, compliance and J-integral concepts are used to study J_(IC) and dJ/da that influence the crack propagation. The relations among the plastic hinge, applied load, linear displacement, rotational angle and crack growth leads to a better understanding of the problem as a consequence of this study. The conclusions are: (1) Unstable ductile fracture occurs at the crack propagates before plastic collapse or at dJ/da is smaller than the minimum critical value. (2) LBB (leak-before-break) characteristic of the statically indeterminate rectangular beam is valid if the crack propagates before plastic collapse.