Construction of J-R Curves Using the Common and Concise Formats

Donoso, J
Materials Science Department and Mechanical Engineering Department, Universidad Técnica Federico Santa María, Valparaíso, Chile

Zahr, J
Materials Science Department and Mechanical Engineering Department, Universidad Técnica Federico Santa María, Valparaíso, Chile

Landes, J
MABE Department, The University of Tennessee, Knoxville, TN, USA

(Received 31 October 2003; accepted 23 March 2004)
JOURNAL JAI
Abstract
A new method for constructing J-R curves is presented, which directly generates the J-Da relation in a closed, analytical form. This new method makes use of the Concise Format and the Common Format, both developed by Donoso and Landes. These formats relate load, P, to ligament length, b, and displacement — in the elastic and in the plastic deformation ranges, respectively — and have proved useful in calculations in fracture mechanics. Key to the method is the postulate of a “crack growth law”—a power-law relation between crack extension, Da, and plastic displacement — used to express J_pl in terms of material properties, size parameters, and crack extension, giving rise to a J_pl-Da analytical expression, similar to the power law J = C₁ (Da)^C2 suggested in ASTM Standard Test Method for Measurement of Fracture Toughness (E 1820). A few examples are included to show the use of the method, and comparisons are made with J-Da curves calculated as per ASTM E 1820.

Keywords:
common format, concise format, cracks, ductile fracture methodology, failure assessment diagram (FAD), fracture toughness, J-R curves, test evaluation

Paper ID: JAI12041
DOI: 10.1520/JAI12041

ASTM International is a member of CrossRef.
Author Donoso, J Affiliation Materials Science Department and Mechanical Engineering Department, Universidad Técnica Federico Santa María, Valparaíso, Chile Author Zahr, J Affiliation Materials Science Department and Mechanical Engineering Department, Universidad Técnica Federico Santa María, Valparaíso, Chile Author Landes, J Affiliation MABE Department, The University of Tennessee, Knoxville, TN, USA Title: Construction of J-R Curves Using the Common and Concise Formats Symposium: Fatigue and Fracture Mechanics: 34th Volume, 2003-11-21
Committee: E08 on Fatigue and Fracture