Multiscale damage modelling of 3D weave composite by asymptotic homogenisation

Understanding the failure behaviour of three-dimensional weaved composites is necessary to allow the design of weave forms appropriate for application, or to predict the failure mode a component will undergo. The different effects at different length-scales call for multi-scale simulation. In this work, a finite-element model is proposed using the asymptotic homogenisation method to distribute macro-scale stresses to the micro-scale, i.e. yarns and matrix, in a repeating unit cell (RUC) model. The stresses in the yarns and matrix are then used in a continuum damage model to determine localised stiffness degradation, and the cell properties are homogenised to determine the macro-scale effect. The model is demonstrated by simulating a through-the-thickness reinforced orthogonally weaved composite, undergoing tensile, compressive and shear loading. The stress-strain response and failure are reproduced and shown to match experimental results. The model reveals the locations of damage initiation, and the progress of damage through the RUC. It is observed that the binder yarns create localised stress concentrations from which the failure process is initiated. It is concluded that the use of such a model can be critical to designing a 3D weave with optimal behaviour.