Study on the Interface Failure Mechanism for Cord/Rubber Composites of Aircraft Tire

As key components of aircraft tires, cord/rubber composites are prone to interface failure under harsh service conditions, particularly due to rapidly increasing ambient temperatures. To elucidate the temperature-dependent interface failure behavior, an analysis method combining mechanical experiments and finite element analysis (FEA) was established based on the shear-lag theory and cohesive zone model. The interface shear properties and failure position were experimentally characterized. A parameter calibration approach was proposed to accurately reproduce the pull-out force–displacement curves and interfacial stress distributions. Results reveal that the interface shear debonding process presents two stages: (i) a stress transfer stage with exponential shear stress decay along the embedded length, and the elastic-based shear-lag model is suitable for describing the uneven stress distribution at the cord/rubber interface; (ii) a damage evolution stage involving progressive interfacial debonding from the constrained end of stress concentration. As temperature increases, the critical pull-out force and interfacial fracture energy significantly decrease, with a decrease of 11.4% in shear strength and 11.5% in fracture energy at 125°C compared to 20°C. Elevated temperatures significantly degrade the modulus and fracture strength of constituent materials, while enhanced deformation compatibility reduces interfacial stress concentrations. The failure initiation site transitions from the adhesive boundary to the rubber matrix, indicating a shift in the dominant failure mechanism. The exponential CZM under pure shear conditions and calibrated parameters yielded high-fidelity simulations. This study highlights the interface degradation mechanisms under thermal influence, offering valuable insights for the design optimization and performance prediction of fiber-reinforced elastomeric composites.