The compressive behaviour of composites including fiber kinking: modelling across the scales

A multiscale strategy is proposed for the simulation of compressive failure by kinking in laminated samples. The model is based on an hybrid description of the material: the composite is seen as an assembly of elementary cells made of homogenized fiber-matrix material and interfaces that are used as potential minimum cracking surfaces to explicitly represent discrete phenomena like splitting and localized delamination. The enrichment proposed in this study concerns the response of the elementary cells in compression/tension and shear. A nonlinear constitutive model inherited from a microscopic kinking theory and parametrized by the statistical fiber waviness is implemented. The average kink-band width defines the cells width, as a characteristic length of the model. Simulations of small structural samples are then performed with this model to illustrate its capabilities, the influence of boundary conditions and statistical fiber waviness, and the natural interactions between kinking and other degradation mechanisms.