The Mechanical Characteristics and Model With Interlayer Debonding for CCFRP Under Uniaxial Tension Conditions

ABSTRACT In this paper, the mechanical properties of continuous carbon fiber‐reinforced polymer composites (CCFRP) with three ply angles at varying strain rates were investigated through simulation and experimental methods. A novel mechanical model based on the classical laminate theory is established to consider the debonding between layers of multi‐layer structures. This model incorporates the structural characteristics of laminated plates and the physical deformation mechanism of deformation. The results demonstrate that the stress–strain characteristics of ±45° ply angle specimens under diverse strain rates exhibit minimal discrepancy due to the comprehensive influence of the PC matrix, carbon fiber, and the interfacial bonding properties during tensile processing. At an identical strain rate, the specimen with a ±45° ply angle displays superior mechanical properties. The tensile deformation process of composite materials can be divided into three stages: deformation coordination stage, uncoordinated deformation stage, and damage stage. Based on the orthotropic and isotropic constitutive equations, the interlaminar stress characteristics are given in the multilayer structure in the deformation coordination and uncoordinated deformation stages. Considering the complex interlaminar stress state and stiffness degradation caused by interlaminar debonding and composite monomer (CM) damage, the mechanical model of interlaminar debonding of the multilayer structure is established, and the validity and accuracy of the model are verified based on the mechanical parameters obtained from experiments and finite element simulation.