Abstract:

ESDU 94019 introduces a Fortran program (ESDUpac A9419) that calculates the through-thickness radial and shear stresses in a specially-orthotropic section subjected to a bending moment, and radial and tangential forces. It provides a distribution of the stresses over a mesh throughout any part of the corner defined by the user. The corresponding moment and forces just to cause failure at any point in the corner are also calculated, that is in the same ratio to each other as those initially input. The transverse failure criterion applied is the quadratic stress equation due to Chang and Springer and it requires values for the ply material compressive, tensile and shear strengths in the through-thickness direction to test for material failure and those same values at the ply interface to test for interface failure. The program is based on the theory of elasticity for a homogeneous anisotropic material and the appropriate equations are detailed. The program tests that the laminate analysed conforms to that assumption and provides a warning if it fails that test together with an assessment of the underestimate of the maximum stress that may then occur. Comparisons are made of results obtained with the program and other results derived from the literature for both experiments and finite element analyses. The input to and output from the program are explained and illustrated by a worked example.