Fracture mechanics models for the analysis of composite materials with a nonlinear matrix (original) (raw)

2013, Icf10 Honolulu 2001

A model for reproducing the constitutive flexural response of a fiber-reinforced composite material with a non-linear matrix is proposed. The nonlinearity of the matrix is modelled by considering a distribution of closing forces onto the crack faces which increases the fracture toughness of the cross-section with a shielding action. The constitutive flexural response depends on three dimensionless parameters:w E c , which controls the extension of the process zone, N (1) P and N (2) P , called brittleness numbers, which are related to the reinforcement phases. The role of the specimen size scale is fundamental for the global structural behaviour, which can range from ductile to brittle simply with the variation of the two brittleness numbers. They are functions of matrix toughness, reinforcement yielding or slippage limit, reinforcement volume fraction and global structural size. The application of the model to steel bar reinforced high-performance concrete with fibers is in good agreement with the experimental results.