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Mixed-mode fracture in off-axis unidirectional graphite-epoxy composites

Conference ·
OSTI ID:5041575

This paper discusses the results of a fracture experiment, in which matrix-dominant mixed-mode cracks are induced with controlled propagation direction and controlled values of mode-II to mode-I ratio. The test specimens used belong to a class of off-axis, doubly side-notched unidirectional graphite-epoxy composite. By varying the off-axis angle from 0 to 90/sup 0/, a wide range of mixed-mode cracking conditions are created under a simple uniaxial tension. From the test results the mixed-mode material fracture toughness measured in terms of the critical energy release rate G/sub (I,II)c/ is determined as a continuous function of G/sub II//G/sub I/ ratio.

Research Organization:
Lawrence Livermore National Lab., CA (USA); Drexel Univ., Philadelphia, PA (USA)
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
5041575
Report Number(s):
UCRL-87827; CONF-821023-1; ON: DE82019108
Country of Publication:
United States
Language:
English