Carbon fiber pull-out analysis for composite materials by considering interface properties

An improved shear-lag model is adopted in this paper to study the fiber pull-out by considering interface properties in a representative volume element (RVE). The surface roughness, represented by grooves distributed around the fiber, is introduced to analyze the influence of roughness on fiber pull-out comparing it with a round fiber. The influence of groove shapes is also discussed. The interfacial stiffness is introduced in the improved shear-lag model by the cohesive zone modeling to simulate a practical interface connection. To represent the residual stress in composites, a pressure load is added on the surface of the RVE to analyze its influence on the fiber pull-out. The results show that the proposed theory can accurately predict the stress distribution in the RVE. Furthermore, the maximum reaction force increases with an improvement in roughness and interfacial stiffness, while the pressure can improve the reaction force in the third stage of fiber pull-out process. The proposed theory can predict the stress field and fiber pull-out process accurately. It can improve the efficiency and effectivity of micro-experiment with the reference of theoretical results. The results obtained using the proposed theory in this research can also be useful for the design and analysis of composite materials.