Cohesive zone analysis of cylindrical ice adhesion: Determining whether interfacial toughness or strength controls fracture

Abstract Ice accretion remains an unsolved challenge in many industrial and residential applications. The iced area can vary from ~1 cm2 to many square meters depending on the situation, and this directly affects the ice debonding mechanism. The fracture of short interfaces is controlled by interfacial shear strength, whereas interfacial toughness dominates the fracture of longer interfaces. The transition from strength-controlled to toughness-controlled fracture occurs at a critical interfacial length. Here we study the fracture mechanics and debonding of ice from several polymeric materials evaluated by the common Zero-Degree Cone Test (ZDCT). Cohesive zone analyses assuming Dugdale-type and linear cohesive laws are performed in cylindrical coordinates. For most materials, the calculated critical length is smaller than the actual interfacial length previously used in the ZDCT, indicating that ice detachment was controlled by interfacial toughness. Good agreement was observed between the values of interfacial toughness calculated in the present study and those reported in the literature. From the data, lower bounds for the ice adhesion strengths are estimated based on the actual length of ice. Our analysis indicates that the prior fracture stresses measured using the ZDCT were not the material's ice adhesion strength, but rather the asymptotic detachment load per interfacial area. Overall, the zero-degree cone test should not be used to measure the ice adhesion strength with its prior or current dimensions, but is an excellent tool for characterizing the interfacial toughness between ice and a material.