Stress concentration in composites laminates

Abstract

This paper presents the result of a stress analysis conducted on orthotropic composite laminae with multiple holes subjected to static loads. The hole configurations include two circular holes with different radii in a finite-width lamina. Numerical analysis using Boundary Element Method has been performed on three types of composite laminae: HMS Carbon Epoxy, Kevlar- 49 Epoxy, and Boron Epoxy. The variations of stress concentrations, general stress distributions, and failure stress around the perimeter of the holes for different fibre orientations concerning different geometric parameters are presented in graphical form and discussed. Geometric parameters varied include the relative size of the holes, the distance between the circular holes, and the distance between the hole edges to lamina edges. Compared to isotropic materials, it is observed that the position of failure in an orthotropic lamina does not always coincide with areas of maximum stress concentration.