A Novel Approach to Investigate Transient Stress Distribution Caused by Fiber Breakage in Simple and Hybrid Composite Materials

The present research work concerned with the transient stress distribution created in the composite material due to fiber breakage. Transient stress is the dynamic response of the system due to discontinuity in the fibers, from the moment of discontinuity to the moment of reaching the steady state. For this purpose, the dynamic equilibrium equations governing the composite lamina with finite dimensions and in the presence of discontinuity have been extracted and the effect of moving the location of the fiber discontinuity, changing the type of fibers and matrix, changing the width of the matrix, and finally the effect of the hybridization of the composite material on the stress concentration coefficient and shear stress created in it have been investigated. Shear-lag’s theory was used to derive the governing dynamic equilibrium equations, and the explicit finite difference method was applied to solve the differential equation of fiber displacement. The results of current study showed that the maximum stress concentration is created at the tip of the crack (place of fiber breakage) and with the increase in the number of broken fibers and the displacement of the fracture location toward the edges, the stress concentration coefficient and the amount of shear stress created also increase.