Prediction of the anisotropic damaged behavior of composite materials: Introduction of multilocal failure criteria in a micro-macro relationship

In an SMC composite two damage processes are observed: fiber fracture and interfacial debonding. Local criteria of damage initiation were introduced in a micro-mechanical model to reproduce these phenomena and predict the material behavior. The model is based on the stiffness prediction by the Mori and Tanaka approach. Tensile stress-strain curves until total failure were simulated. The evolution with damage of the elastic constants is compared with ultrasonic and mechanical measurements and with micro-mechanical calculations. In an Al/SiCp composite damage was identified to be particle fracture. A statistical local criteria of particle fracture is then introduced into the model. Tensile behaviors including plasticity are simulated with or without damage and compared with experimental results. Moreover, to model the very local anisotropy due to damage, we develop the equivalent anisotropic undamaged inhomogeneity (EAUI) method.