Nonlinear behavior simulation of ceramic-matrix composites using constituent-volume homogenization method

The nonlinear behavior of ceramic-matrix composites is affected by interface debonding and fiber pull-out. In this paper, we propose the constituent-volume homogenization method (CVHM) to replace the conventional bundle homogenization method, in order to model the behavior of trans-element debonding in woven structures using finite element method. Based on the CVHM, we establish the elastic relation of the relative motion between the fiber and the matrix, and the elastic constitutive relations for the constituents. Methods have also been developed to calculate the microscopic local stress of bundle under pull-out and multiaxial loads. Based on the above studies, we develop a procedure to analyze the stress-strain relation of braided composites using the CVHM. To validate the proposed method, we estimate the nonlinear behavior of the 2D plain-weave ceramic-matrix composites and compare the results with experimental data. The influence of interface shear strength (ISS) and the fiber ultimate tensile strength (UTS) on the nonlinear behavior is investigated.