At coupon level, the residual strength of impacted laminates is assessed through compression after impact (CAI) tests; as a complement to the experiments, numerical tools are sought that predict the behavior of delaminated composites.
An eigenvalue analysis is then done to determine the modal response of impacted laminates.
Finally, the compressive failure mechanisms of impacted laminates are discussed depending on matrix nature, with a particular attention paid to the damage scenario (buckling and propagation of 0° fibers failure).
This work also serves the purpose of helping the engineering and design departments to carry out an accurate reliability analysis on the behavior of impacted composite structures.
Then, the behavior of impacted specimens under compressive loading is discussed along with the effects of ply drop-off parameters (taper angle, ply drop-off disposition and configuration) and impact point location on the failure mechanism.
Using visual observation, C-Scan and thermal de-ply experimental measure methods, the surface damage and internal delamination of the specimens are described in detail to provide more information to understand the mechanical behaviors of impacted or quasi-static indented CFRP laminates.
A probabilistic model was developed in order to estimate the variation in residual strength of the impacted laminates with temperature.
Visual inspection of the impacted laminates revealed similar deformation mechanisms for composites reinforced with microbraids having different architectures and of different material.
The impact behavior of aluminum/epoxy laminates was studied by changing the number of layers and the interface strength.
Furthermore, the extent of the damage of an impacted laminate was related to the velocity profile on its free surface.
