The Effect of Fibers Hybridization on Hole Stress Concentration in a Hybrid Composite Lamina Subjected to Matrix Plasticity

Hole stress concentrations in long fibers and their surrounding matrix bays are examined in a hybrid composite lamina. It is assumed that all fibers lie in one direction while loaded by a force p at infinity in the direction of fibers. The width of the lamina is considered to be finite and bears a hole as a defect. Due to presence of excessive shear stress in the matrix bays bounding the hole, a yielded zone of size 2a0 is developed around the hole. Shear lag model (SLM) is used to drive the displacement and stress fields. The resulting equations are solved analytically based on boundary and continuity conditions. Compared to a lamina with a single type fiber, a hybridized model shows lower stress concentrations in high modulus (HM) fibers bounding the hole as opposed to those of low modulus fibers (LM) subjected to the same condition.