Microscale Modeling and Damage Mechanisms of Fiber‐Reinforced Composites With Perpendicularly Embedded Optical Fibers

ABSTRACT This paper investigates the microscale damage and failure mechanisms of carbon fiber reinforced polymer (CFRP) laminates with perpendicularly embedded optical fibers through numerical simulation. Guided by microscopic observations, particularly the characteristic “eye‐shaped” resin‐rich zone and adjacent fiber bending disturbance, a representative volume element (RVE) model was constructed to represent the composite microstructure. The extended Drucker‐Prager plasticity model and cohesive zone model were employed to simulate the micromechanical response and failure evolution of the matrix and interface under axial tensile and compressive loading. Simulation results show that under axial tension, interfacial debonding initiates due to stress concentrations around the optical fiber, while matrix cracking begins at the corners of the resin‐rich zone under high tensile stress. These cracks grow and eventually link with the interfacial debonding zones, leading to final failure. Under axial compression, interfacial debonding preferentially occurs above and below the optical fiber, with debonding rapidly propagating along the boundary of the resin‐rich zone, and the final failure is characterized by localized fiber buckling and matrix cracking above and below both corners of the resin‐rich zone. The micro‐damage morphologies obtained from the simulations show good consistency with the experimental observation results. Additionally, voids were consistently observed within the resin‐rich zone, which reduces the local strain transfer efficiency to the optical fiber and promotes damage localization. This study provides important micromechanical insight into the failure behavior of smart composite materials and offers theoretical guidance for the structural optimization of CFRP laminates with embedded sensing elements.