Compressive strength estimation of continuous carbon fibre/epoxy resin composite by micro-mechanical numerical modelling

The axial compressive strength of continuous fibre composites is often the key design parameter used by mechanical engineers. The complex interactions between the fibres and the matrix requires the use of sophisticated numerical models to estimate this property. A preliminary design step is conventionally used for the dimensioning of composite structures. This step requires quick tools such as analytical criteria. In this work, we discuss such a criterion and its input parameters related to the nonlinear shear behaviour of the unidirectional ply. These parameters are usually measured using experimental techniques. We show that a simple micro-mechanical numerical model (representative hexagonal volume element with periodic boundary conditions), easily usable by engineers, makes it possible to estimate this nonlinear shear behaviour, thus reducing the number of tests required. This also makes it possible, on the one hand, to accelerate the preliminary design test, and, on the other hand, to select the constituents and thus tailor the material response.