Multiscale damage modeling with the “Morphological Approach” to highlight particle size and interaction effects in highly-filled particulate composites

This paper concerns the modeling of interfacial damage in highly-filled particulate composites (e.g. solid propellants), thanks to a specific multi-scale approach recently developed, called “Morphological Approach”. This approach was shown to provide both the homogenized and local responses of the composite taking into account heterogeneity of the strain field within the matrix. In this paper, the M.A. ability to deal with particle size and complex interaction effects expected in highly-filled composites is studied. Considering for simplicity the constituents (particles and matrix) as linear elastic, numerical computations are performed on simple periodic microstructures, monomodal random microstructures and finally a bimodal random microstructure. Particle/matrix debonding chronology is analyzed with respect to the particle size as well as the influence of interactions between particles. The role of interfaces orientation is also addressed. The M.A. is shown to account for preferential damage on the largest particles. Moreover, M.A. estimates show that the more important the particle volume fraction, the earlier the first nucleations. Results are in accordance with experimental studies and full-field simulations available in the literature.