Composite Interfaces, Vol.27, No.10, 937-951, 2020
Synergistic effects of interface slip and fiber fracture on stress-dependent mechanical hysteresis of SiC/SiC minicomposites
In this paper, the synergistic effects of interface slip and fiber fracture on stress-dependent mechanical hysteresis of SiC/SiC ceramic-matrix minicomposites (mini-CMCs) are investigated. Upon cyclic loading/unloading, the relative slip between the fiber and the matrix, and the fracture fiber affect the hysteresis behavior of mini-CMCs. The micro-stress field of the damaged mini-CMCs is obtained through shear-lag analysis, and cyclic loading/unloading hysteresis strain is related with the stress level, interface slip, and broken fiber. The effects of constituent properties and internal damage state on cyclic loading/unloading interface slip and hysteresis loops of SiC/SiC minicomposite are analyzed. The experimental matrix cracking density, stress-dependent mechanical hysteresis and interface slip of Hi-Nicalon(TM), Hi-Nicalon(TM) Type S, and Tyranno(TM) ZMI SiC/SiC minicomposites are predicted. The interface debonding and slip range, and mechanical hysteresis loops of SiC/SiC minicomposites are affected by the stress level, constituent properties of the fiber volume, interface properties, and damage state of matrix cracking and broken fiber subjected to cyclic tensile loading.
Keywords:Ceramic-matrix composites (CMCs);Minicomposite;Hysteresis loops;Interface slip;Fiber failure