Damage Mechanisms and Stress Field Evolution of Two Dimensional Woven Twill <scp>CFRP</scp> Under Quasi‐Static Compression

ABSTRACT Woven Carbon Fiber Reinforced Polymer (CFRP) is widely applied in industrial applications due to its high specific strength and excellent design flexibility. In this study, a meso‐macro finite element modeling (FEM) for the quasi‐static compressive behavior of two‐dimensional woven twill CFRP is developed and validated through quasi‐static compression experiments. The evolution of stress–strain fields and interfacial damage is investigated using finite element analysis (FEA). Under quasi‐static compressive loading in the weft (Y) direction, interlayer failure, matrix cracking, fiber‐matrix debonding, and fiber fracture occur sequentially as the interlayer strength, matrix compressive strength, fiber‐matrix interfacial strength, and fiber shear strength are exceeded. During Y‐direction compression, increased fiber bundle flexibility leads to local buckling and the formation of kink bands. Matrix stiffness is identified as the dominant factor governing the kink‐band formation process. Under quasi‐static compression load perpendicular to the laminate plane (Z‐direction), interlayer failure, matrix cracking, fiber fracture, and fiber‐matrix debonding occur in sequence. Local ply cracking is observed, accompanied by micro‐buckling between fibers near the split regions, resulting from the development of internal kink bands in the Z‐direction.