Generalized Stress Intensity Factors at the Fiber End in Fiber Reinforced Plastics

摘要

To evaluate the mechanical strength of fiber reinforced composites, it is necessary to consider singular stresses at the end of fibers because they cause crack initiation, propagation, and final failure. The singular stress field is controlled by geseralized stress intensity factor (GSIF) defined at the fiber end. In this study, periodic and zigzag arrays of cylindrical inclusions under longitudinal tension are analyzed by the application of the bady force method. The unit cell region is approximated as an axisymmetric cell; then, the problems are solved on the superposition of two auxiliary problems under different boundary conditions. The GSIFs are systematically calculated with varying the elastic modulus ratio and spacing of fibers. The effects of volume fraction and spacing of fibers are discussed in short fiber reinforced plastics.