Accession Number : ADA302677

Title :   An Analysis of Cracks Emanating From a Circular Hole in Unidirectional Fiber Reinforced Composites. Part 2.

Descriptive Note : Final rept.,

Corporate Author : ILLINOIS UNIV AT URBANA DEPT OF THEORETICAL AND APPLIED MECHANICS

Personal Author(s) : Wang, S. S. ; Yau, J. F.

PDF Url : ADA302677

Report Date : FEB 1981

Pagination or Media Count : 45

Abstract : An analytical method is developed for cracks emanating from a circular hole in an off-axis unidirectional fiber-reinforced composite. The method is formulated by using conservation laws of elasticity and fundamental relationships in anisotropic fracture mechanics. The method provides a very convenient and accurate means to examine the complicated crack behavior, when used in conjunction with a suitable numerical scheme such as the finite element method. The formulation is eventually reduced to a system of linear algebraic equations of mixed-mode stress intensity factors. Fracture parameters, describing crack-tip of deformation and fracture in the composite, are obtained explicitly. Effects of material anisotropy and crack/hole geometry are examined also. Of particular interest are the energy release rates associated with crack extension; their values are evaluated for various cases. Results show that mixed-mode stress intensity factors and energy release rates associated with the cracks emanating from a hole change very appreciably with fiber orientation in the composite. K sub I and G increase monotonically with increasing e; but K11 reaches its maximum at theta = 45 deg, and then decreases gradually as theta increases further. (MM)

Descriptors :   *FIBER REINFORCED COMPOSITES, *CRACK PROPAGATION, STRESS ANALYSIS, FINITE ELEMENT ANALYSIS, DEFORMATION, ELASTIC PROPERTIES, ENERGY TRANSFER, GLASS, FRACTURE(MECHANICS), HOLES(OPENINGS), ANISOTROPY, EPOXY COMPOSITES, UNIDIRECTIONAL, J INTEGRALS.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE