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Numerical Comparison of Global and Local Fracture Criteria in Compact Tension and Center-Crack Panel Specimens

出版	ASTM International, 1988
URL	http://books.google.com.hk/books?id=s-t9zgEACAAJ&hl=&source=gbs_api

註釋Numerical computation of the stress-strain fields ahead of the crack tip of compact tension (CT) and center-crack panel (CCP) specimens were performed. Various crack length to width ratio and strain hardening exponents were investigated. The results of these calculations were used to simulate numerically either brittle fracture or ductile rupture. For this purpose, the comparison between global fracture criteria, such as JIc or the critical crack-tip opening displacement [(CTOD)c], and local fracture criteria is made. It is shown that both types of criteria provide similar results when the specimens are loaded under small-scale yielding. On the other hand, under large-scale yielding significant differences are found. Local fracture criteria are used to specify the validity range for the global parameter, JIc. It is shown that this validity range depends both on the specimen shape and on fracture micromechanisms.