Influence of Plastic Deformation of Particulates on Flexure Toughness of Brittle Matrix Composite

In ductile-particulate reinforced composites with relatively low filler contents, the fracture toughness is dominated by the crack trapping effect. In this paper, this phenomenon is discussed in detail in context of R-curve analysis. The total fracture work is decomposed into the work of separation of matrix and the traction work associated with particulate rupture. It is concluded that, since the energy dissipation subsequent to the onset of unstable crack propagation does not affect the critical condition, the load bearing capacity of the particulates cannot be fully utilized. A closed-form expression relating the fracture toughness to the hardening behavior is obtained.