Boundary-layer effects in composite laminates. II: Free-edge stress solutions and basic characteristics. (English) Zbl 0504.73043

Wang, S. S.; Choi, I.

J. Appl. Mech. 49, 549-560 (1982).

Summary: Boundary-layer effects in composite laminates are considered. Based on the theory of anisotropic elasticity and Lekhnitskii’s complex-variable stress function formulation, the exact laminate elasticity solution is derived for the problem. The solution contains the exact boundary-layer stress singularity and higher-order terms in eigenfunction series. Convergence and accuracy of the solution are studied, and present results are compared with existing approximate numerical solutions. For illustrative purposes, the complete solution for a symmetric [45/-45 / -45/45] graphite-epoxy composite is presented to elucidate fundamental characteristics of the boundary-layer effects. Detailed stress distributions in the boundary-layer region are determined. Boundary-layer stress intensity factors are introduced to characterize the singular edge-stress field. Physical significance of the parameters is discussed in the realm of fracture initiation and failure modes in the laminate boundary region.
For Part I, see Zbl 0504.73042.

MSC:

74E30	Composite and mixture properties
74E10	Anisotropy in solid mechanics
35P10	Completeness of eigenfunctions and eigenfunction expansions in context of PDEs
74S99	Numerical and other methods in solid mechanics
74G70	Stress concentrations, singularities in solid mechanics

Keywords:

boundary-layer effects; composite laminates; Lekhnitskii stress function; exact laminate elasticity solution; exact boundary-layer stress singularity; higher-order terms in eigenfunction series; convergence; accuracy; symmetric graphite-epoxy composite; stress distributions; stress intensity factors; singular edge-stress field

Citations:

Zbl 0504.73042