Rate-Dependent Interfacial Behavior and Failure Mechanisms of Cord/Rubber Composites for Aircraft Tires

The rate-dependent response of cord/rubber composites (CRCs) is critical to the structural integrity of aircraft tires during touchdown impact. In this work, an integrated experimental-numerical framework is developed to investigate the interfacial behavior of aramid/polyamide (AF/PA) hybrid cord/rubber systems over a wide range of pull-out velocities (1–10⁴ mm/s). High-rate tensile and pull-out tests show pronounced rate sensitivity in both the bulk constituents and the cord/rubber interface, as reflected by increased stiffness, peak pull-out force, and failure-mode transition with increasing velocity and interface length. Multiscale finite element analyses further reveal strong axial stress concentration near the loaded end together with circumferentially localized high-shear regions induced by the twisted cord geometry to interpret mechanical responses and support interfacial parameter identification. Based on these observations, a rate-dependent cohesive zone model is established by extending the Xu-Needleman potential through an equivalent separation rate and logarithmic evolution laws for the interfacial fracture energy and tangential characteristic separation. The model reproduces the apparent stiffness and peak pull-out force with maximum errors of 13.1% and 12.7%, respectively, for interfacial-debonding cases over the investigated range. A rate-dependent failure map is further constructed, capturing the transition from interfacial debonding to cord fracture as pull-out velocity and embedded length increase. The proposed framework provides mechanistic insight into transient interfacial load transfer and a predictive basis for the design of aircraft-tire CRCs under impact loading.