Stress concentration in laminated composites with a central circular hole under biaxial load

The anisotropic nature of the laminate composites creates a unique opportunity and also a great challenge for tailoring its properties according to the design requirements. In this work investigating the strength of laminate composite, a nonlinear finite element analysis was used to simulate the stress concentration in a two dimensional element caused by a central circular hole subjected to the biaxial loading. The effects of elastic and plastic deformation of a metallic material, fiber orientation and stacking order of a laminated composite on stress concentration were investigated. This evaluation provides a clear indication and a key step in understanding failures initiated by stress concentration which may lead to the growth of a crack. Comparison between the effects of the hole both on a metallic material and on a fiber-reinforced laminate exposes a totally different situation. In general, the stress concentration depends largely on the material properties, the layer stacking order, and the orientation.