Stress analysis of symmetric laminates with obliquely-crossed matrix cracks

Abstract

Simple methodology for stress analysis of laminates with obliquely-crossed matrix cracks is presented. An oblique coordinate system along the matrix cracks is introduced in conjunction with the derivation of oblique coordinate tensor components. Using displacement/strain covariant components and force/stress contravariant components, it is shown that the obliquely crossed crack problem with any oblique angle can be treated as the orthogonally-crossed crack problem, which ensures that obliquely-crossed cracked laminates can be regarded as orthogonally-crossed cracked laminates with appropriate transformation of properties. This approach is combined with twodimensional shear-lag analysis and analytical solutions of [ m/90n]s and [S/ m/90n]s laminates with matrix cracks in both- and 90-plies under general in-plane loadings are obtained in terms of oblique coordinate components. Calculated stress distributions are compared with 3D FEM results and the effectiveness of the present analysis is verified.