Effect of fiber fracture and interfacial debonding on the evolution of damage in metal matrix composites

A new approach for modeling the behavior of laminated composite structures using computational methods is presented, considering damage evolution at the micromechanical level. Micromechanical models are developed to predict the stress-strain response of a composite lamina explicitly accounting for the local damage mechanisms such as fiber fracture and interfacial bonding. The model is applied to metal matrix composites and hence the inelastic constitutive behavior of the matrix phase is included. The stochastic variation of the fiber properties is incorporated in this simulation using the two-parameter Weibull model. The effect of fiber volume fraction and the properties of the fiber, matrix and interface on the damage evolution is studied using this approach. A constitutive damage tensor for the composite lamina is developed from the micromechanical models which can be input into laminate structural analysis codes.