Damage in composite materials initiates at the length scale of one or a few fiber diameters, governed by the local stress fields. Further progression of the failure events is governed by conditions existing in a material volume representative of geometrical aspects such as fiber orientation and thickness of the plies, as well as the extent of stress field perturbations caused by damage entities. Failure of a composite structure occurs at attainment of a critical state in its response related to the designed functionality. Assessment of failure must therefore involve analyzing failure events from initiation until the relevant criticality state, with proper account of the length scales at which the respective failure mechanisms occur. Approaches for this purpose are necessarily of a multiscale nature. This chapter discusses a particular approach that incorporates the micro-, meso-, and macroscales in one single framework and is aimed at describing the deformational response of multidirectional composite laminates with multiple cracking in different orientations.
Godkänd; 2015; 20151201 (andbra)