MODELLING FAILURE USING PHYSICALLY-BASED 3D MODELS AND A SMEARED FORMULATION

摘要

Three dimensional failure criteria for laminated fibre-reinforced composites with unidirectional plies, based on a physical model for each failure mode and considering non-linear matrix shear behaviour, are developed. The criterion for matrix compression failure is based on the Mohr-Coulomb criterion and also predicts the fracture angle. For fibre kinking, an initial fibre-misalignment angle is considered to trigger failure. The criterion predicts the plane where kinking takes place. Applications validating the model against experimental data are presented. The failure criteria are implemented in an explicit Finite Element code, using a smeared formulation to avoid mesh dependency. All the properties used by the model have a clear physical meaning, and are obtained experimentally. The model is shown to reproduce key aspects observable during failure of standard specimens, and is used to simulate the crushing of a (-45{sub}2,45{sub}2){sub}s column. The physics of the deformation process and the form of the load-displacement curve agree well with the experiments.