In this paper an overview of a numerical approach to evaluate the mechanical behaviour until failure of multi-axial composites and the validation of the method against experiments is presented. The procedure is a multi-scale modelling technique essentially based on the solution of nested boundary value problems, one for each scale. The main assumption at each scale is the periodic distribution of the reinforcements to apply the homogenization theory for periodic media. The modelling is implemented in a two-scale computational homogenization procedure to study the mechanical behaviour of textile composites and multi-layer stitched composites. The experimental data on a glass textile plain weave composite and a multi-axial multi-ply carbon st...