Fracture Modeling of Fiber Reinforced Cementitious Composites

摘要

A fracture model is developed to generate the entire crack growth resistance curve of fiber reinforced cementitious composites including the steady state fracture energy. The crack growth mechanism in these materials is described in terms of three zones: (1) a stress-free zone; (2) a pseudo-plastic zone, where the matrix has cracked but the fibers bridging the crack still provide some resistance to pull out; and (3) a process zone. The proposed fracture model assumes that the main portion of the energy required during fracturing of the material comes from fiber pull out within the pseudo-plastic zone. It is also assumed that the main crack in the composite propagates with a constant shape while its cohesive force-displacement law is being fully developed. Results predicted by the model are shown to be in reasonably good agreement with experimental data.