Interface fracture analyses of a bicrystal niobium/alumina specimen using a cohesive modelling approach

The present paper examines the interface fracture of a bicrystal niobium/alumina specimen using a cohesive modelling approach. Crystal plasticity theory has been used to model the single crystalline niobium. The effect of different cohesive law parameters, such as cohesive strength and work of adhesion, has been studied. The cohesive strength is found to have a profound effect on the crack growth resistance and fracture energies as compared with the work of adhesion. The cohesive model parameters are identified by validating the finite element analyses results with experiments. Theoretical interlink between the local adhesion capacity and macroscopic fracture energies has been analysed. The results presented in this work provide an insight into the role of cohesive strength and the work of adhesion in macroscopic fracture is also presented which can be used by experimentalists to design better bimaterials by varying the cohesive strength and the work of adhesion.