Micro-scale fiber/matrix stress concentrations in unidirectional glass/carbon hybrid composites under transverse loading

Abstract

Fiber/matrix interface stresses and micro-scale stress concentrations (SCs) under transverse loading were analyzed for hybrid composites, reinforced with glass and carbon fibers. A finite element model was implemented using parametric modeling technique to determine the stresses in the matrix and fiber/ matrix interface. Several micro-scale finite element models were generated for the analyses with various combinations of fiber material, fiber size, volume ratio and fiber spatial distribution models. Models with single fiber type (non-hybrid composites) were also analyzed to understand the hybridization effect on the stresses. The results reveal the effect of the presence of different fiber types and their arrangement on the micro-scale stress distributions and fiber/ matrix interface behavior. Under transverse loading, when the same type of fibers are aligned with the loading direction, the SCs on the stiffer fibers are larger than the case in the composite with the single stiffer fiber type. When these fibers are aligned with the direction perpendicular to the loading, the SCs on the stiffer fibers are lower. Fiber material type was more effective than the fiber size and fiber volume ratio enhances the effect of hybridization on the stress distributions. According to the authors' knowledge this is the first study investigating the transverse SCs in hybrid composites at the micro-scale level