ABSTRACT
The presence of inclusions like fibers or particulates in heterogeneous ductile material microstructures often has adverse effects on their failure properties like fracture toughness and ductility. Important micromechanical damage phenomena that deter material properties include second phase inclusion fracture and splitting, interfacial decohesion as well as matrix cracking. These damage
mechanisms are sensitive to local microstructural parameters, such as inclusion dispersion, size, shape, interfacial strength, etc. Various experimental and numerical studies [381, 254, 311, 281, 59, 204, 253, 82, 275, 151, 239] have been conducted to understand the influence of morphological factors such as volume fraction, size, shape, and spatial distribution as well as constituent material and interface properties on the deformation and damage behavior. These studies have concluded that failure mechanisms are highly sensitive to local reinforcement distribution, morphology, size, interfacial strength, etc. Experimental studies with metal matrix composites (MMC) in [59] have established that particles in regions of clustering or preferential alignment have a greater propensity toward fracture than those in regions of dilute concentration. Christman et al. [82] have shown that local plastic flow is very sensitive to shape of reinforcements. Scanning electron microscopy of damaged microstructures by Hunt et al. [205, 204] and Kiser & Zok [223] show particle distribution, size, and shape can significantly alter the extent of microstructural damage and the onset of material failure. Preferential damage is usually a function of matrix straining and particle locations. Many characterization studies with 2D microstructures (e.g., [384, 449, 330, 328]) have also been conducted to understand the relation between microstructural morphology and damage.
