STRESS-CONCENTRATION AROUND HOLES IN COMPOSITE LAMINATES WITH VARIABLE FIBER SPACING

An 18 degree-of-freedom higher-order triangular plane stress element is developed to investigate the effect of variable fiber spacing on the stress concentration around a hole in a composite laminated plate subjected to in-plane boundary loadings. This element accounts for the irregular in-plane elastic properties across the element domain, thus, the nonuniformly spaced fibers in the laminate can be easily incorporated into the element stiffness matrix through the fiber content calculated at each Gaussian integration point. Results show that reducing the fiber volume ratio near the hole edges can significantly reduce the stress concentration in that region.