Mode Transition and Cohesive Failure during Ice Debonding from Microstructured Surfaces.

Understanding the micromechanics of debonding ice on microstructured surfaces is essential to the rational design of icephobic materials. However, the competition between interfacial debonding and cohesive fracture, along with microscale stress evolution under complex loading fields, remains unclear. This study develops a coupled computational framework that integrates a cohesive zone model with the extended finite element method to systematically investigate the loading-induced failure process of ice-solid interfaces. This framework accurately captures the mechanical competition and evolution between interfacial crack propagation and internal fracture within ice under complex structural constraints. We further elucidate stress evolution during debonding and demonstrate that rotational debonding effectively alleviates stress concentrations at the micropillar root through the coupled release of normal and tangential displacements. This provides a fundamental mechanical explanation for the weakening of the mechanical interlocking effect. Furthermore, by extracting nonlinear force-displacement responses for different failure modes, we characterize the mode-dependent mechanical response of microscale debonding. These results provide micromechanical insights into macroscopic ice adhesion and offer quantitative guidance for the morphological design of low-adhesion surfaces.