THE SIGNIFICANCE OF MAXIMUM FORCE ON A FORCE-DISPLACEMENTCURVE WITH STABLE CRACK EXTENSION

摘要

Recently, a new look has been given at the J-R curve construction, based on both the Common and the Concise Format Equations of Donoso and Landes, together with a crack growth law that relates stable crack extension to plastic displacement. Relations have been formulated that allow for an analytical treatment of the J-△a curve, as well as the force-displacement, P-v curve, with inclusion of stable crack growth.Thus, the use of both the Common and Concise Formats and the crack growth law, have made it possible to express the force, P, as a function only of crack length, giving rise to the P-a curve.This curve shows a maximum in force, Pmax, for a critical value of crack length, ac. This paper reviews the concepts of the Common and the Concise Format Equations (C&C Formats), and addresses the issue of the maximum force on the P-v curve, in terms of the J-R curve obtained from that force-displacement curve with stable crack extension.