Multi-scale modeling of heterogeneous adhesives: Effect of particle decohesion

We examine the microscopic toughening mechanisms and their effect on the macroscopic failure response of heterogeneous adhesives made of stiff particles embedded in a more compliant matrix. The analysis relies on a multi-scale cohesive framework first described in Matouš et al. [Matouš, K., Kulkarni, M., Geubelle, P., 2008. Multiscale cohesive failure modeling of heterogeneous adhesives. Journal of the Mechanics and Physics of Solids 56, 1511–1533]. Two microscopic constitutive failure models are incorporated: an isotropic damage model to capture the fracture response of the matrix and a cohesive law to model the inclusion-matrix interfacial debonding. A detailed study of the RVE size is presented followed by a set of examples that illustrate the effect of filler size, volume fraction and particle–matrix interface properties on the macroscopic effective traction-separation law of heterogeneous adhesives.