Characterization of Mode-II Interfacial Fracture Toughness of Ice/Metal Interfaces 2019-01-1947
Airborne structures are vulnerable to atmospheric icing in cold weather operation conditions. Most of the ice adhesion-related work have focused on mechanical ice removal strategies because of practical considerations, while limited literature is available for fundamental understanding of the ice adhesion process. Here, we present a fracture mechanics-based approach to characterize interfacial fracture parameters for the shear behavior of a typical ice/aluminum interface. An experimental framework employing shear push-out test was developed to achieve mode-II fracture conditions at the interface. Both analytical (shear-lag analysis) and numerical (finite element analysis incorporating cohesive zone method) models were used to extract mode-II interfacial fracture parameters. The combined experimental and numerical results, as well as surveying published results for zero angle push and shear lap tests showed that mode-II interfacial strength and toughness can be significantly affected by the method of testing due to geometrically induced interfacial residual stress. As a result, the apparent toughness of zero angle pushout test could reach an order of magnitude higher than those derived from shear lap tests.
Denizhan Yavas, Ashraf Bastawros PhD, Bishoy Dawood, Christopher Giuffre
Iowa State University
International Conference on Icing of Aircraft, Engines, and Structures