Analysis on the process of stress transferring and characterization on the property of “interphase” in three-phase single-fiber composites

In this study, two micro-mechanical models for analyzing the stress transferring in single-fiber composites composed of the fiber, the matrix, and the interphase are developed based on the shear-lag theory. The analytical model has taken into account two micro-damage modes, that is, the interficial debonding and the matrix damage, respectively. So, the real distribution of the shear stress at the interface and the axial stress in the fiber in single-fiber composites under loading can be obtained. An approach based on combining the micro-mechanical model with the single-fiber fragmentation test was utilized to determine the property of the interphase. The more accurate and real shear strength of the interphase in single-fiber composites is determined compared with the previous methods.