AN EFFICIENT STRESS FUNCTION APPROXIMATION FOR THE FREE-EDGE STRESSES IN LAMINATES

A solution method is derived for determining the free-edge stresses in composite laminates. The method is based on expanding stress functions in terms of a harmonic series in the thickness direction. Using the principle of minimum complementary energy, a system of ordinary differential equations is derived for the distribution in the width direction. Cross-ply and angle-ply laminates are examined to establish the validity of the solution. Eight- and 16-ply quasi-isotropic laminates are also examined to demonstrate a convergence criterion based on average stress. The method proves to be a relatively simple and efficient approach for this problem.