Mesoscale Investigation of Crimping Effects and Ductile Failure Mechanisms in Plain‐Woven <scp>CFRP</scp> Under In‐Plane Loads

ABSTRACT Plain‐woven CFRP (PW‐CFRP) exhibits complex nonlinear behaviors, such as crimping effects under axial loading and ductile failure under shear; yet their underlying mechanisms remain poorly understood, and accurate multiscale models are scarce. This study proposes a mesoscale modeling framework that integrates an elastoplastic‐damage matrix model, a 3D Hashin‐type failure criteria for the yarn model with progressive damage rules, and a bilinear cohesive interface model, enabling precise prediction of these nonlinear tensile and shear responses. Validation through digital image correlation, stereomicroscopy, and scanning electron microscopy confirms its reliability. Results reveal that yarn straightening and matrix plasticity drive the crimping effect, while matrix flow and fiber‐matrix interactions govern shearing ductile failure. Comparative analysis shows that the framework outperforms existing models in capturing the matrix‐driven nonlinear behaviors and bridges the gap between experimental observations and mesoscale simulations.