Multiscale modelling of the failure behaviour of fibre-reinforced laminates

The static failure behaviour of fibre-reinforced laminates is examined at the mesoscale and microscale levels of observation using finite element simulations. The actual cracking and delamination processes are simulated with interface elements equipped with a mixedmode damage model. The mesoscale simulations consider a fibre-metal laminate GLARE that is subjected to uniaxial tension. The effect of plasticity in the metal layers on the cracking and delamination processes in the laminate is analysed. The results for a brittle laminate are compared against a closed-form expression derived from energy considerations. In the microscale simulations the transverse failure response is studied of unidirectional fibre-epoxy systems subjected to uniaxial tension. The influence on the failure response by the relative strength of the fibre-epoxy interface and the epoxy matrix is demonstrated for single-fibre epoxy systems. For multiple-fibre epoxy systems the effect of the volume fraction on the failure response is assessed. Finally, the discrete, microscale fracture processes in thin fibre-epoxy layers are coupled to a mesoscale traction-separation law by means of a numerical homogenization approach. It is demonstrated how the effective traction-separation response and the corresponding microscale fracture patterns under mesoscale tensile conditions depend on the presence of microscale imperfections