A combined experimental and numerical approach to investigate the failure behaviors of 3D woven composites under biaxial tensile loading

Abstract

The failure behaviors of 3D woven composites (3DWC) under biaxial tensile loadings are investigated through a combined experimental and numerical approach in this paper. Appropriate biaxial cruciform specimen of 3DWC is first designed according to the experimental requirements. The biaxial tensile experiments are conducted on a servo-hydraulic biaxial testing facility, and then the full-field strain distributions and crack morphologies of cruciform specimens are analyzed in detail. For the multiscale geometric reconstruction of 3DWC, a full-thickness mesoscopic RVC is first extracted from the periodic woven architecture, and then a novel full-scale geometric modeling method is developed to reconstruct the biaxial cruciform specimens of 3DWC. Particularly, in conjunction with the micromechanics of failure theory, a multiscale damage model is proposed to simulate the biaxial failure behaviors of 3DWC. With the stress amplification factor, a transfer relationship between mesoscopic and microscopic stresses is established, and then the damage states of matrix and fibers within yarns can be separately determined. By comparing the experimental and predicted results, the realistic damage mechanism of 3DWC under biaxial tensile loading can be elucidated.