Micro-mechanical damage simulation of 2.5D woven variable thickness composites

• The three-step modeling method is proposed to construct full-size meso-finite element models of ORYWC and IRYWC rapidly. • Six independent damage variables are defined to establish the constitutive relationship of woven composites considering the coupling effect of microscopic damage. • The strength prediction model, which takes into account microscopic damage between components of 2.5DWVTC, is proposed. • The damage evolution rule of ORYWC and IRYWC is obtained by experiments and numerical simulation. With the application of 2.5D Woven Variable Thickness Composites (2.5DWVTC) in aviation and other fields, the issue of strength failure in this composite type has become a focal point. First, a three-step modeling approach is proposed to rapidly construct full-scale meso-finite element models for Outer Reduction Yarn Woven Composites (ORYWC) and Inner Reduction Yarn Woven Composites (IRYWC). Then, six independent damage variables are identified: yarn fiber tension/compression, yarn matrix tension/compression, and resin matrix tension/compression. These variables are utilized to establish the constitutive equation of woven composites, considering the coupling effects of microscopic damage. Finally, combined with the Hashin failure criterion and von Mises failure criterion, the strength prediction model is implemented in ANSYS using APDL language to simulate the strength failure process of 2.5DWVTC. The results show that the predicted stiffness and strength values of various parts of ORYWC and IRYWC are in good agreement with the relevant test results.