ISSN: 0090-3973
Page Count: 7

J-Integral Evaluation of Single-Edge Notched Specimens under Mixed-Mode I/II Loading

Donne, CD
German Aerospace Center DLR, Institute of Materials Research,

Pirondi, A
University of Parma,

(Received 20 March 2000; accepted 5 December 2000)

Abstract

Standard test methods of mixed-mode fracture toughness still do not exist, even though a decrease of fracture toughness with increasing Mode II (shear components) has been observed for a number of steels. A J-estimation scheme for mixed-mode loaded single-edge notched specimens is therefore developed in this paper. In accordance with the ASTM Standard E 1820-99, the evaluation of the plastic part of J is based on the measurement of the dissipated plastic energy weighted by a η^pl-factor. Two different approaches for the η^pl-factor are derived. Factors from both showed good correlation with finite element calculations for the specific case of a compact-tension-shear specimen (C(TS)), Finally, a simple clip gage setup for the measurement of the crack-opening displacements needed for the evaluation of the dissipated plastic energy is presented. The problem of the qualification of the mixed-mode crack initiation data is not specifically addressed, but some general comments on this topic are given at the end of the paper.

Keywords:
ductile fracture, mixed mode, C(TS) specimen, J-integral, η-factor, crack displacement measurement

Paper ID: JTE12251J
DOI: 10.1520/JTE12251J
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