Damage Progression and Interaction in Composite Structures Subjected to Extreme Dynamic Loadings

Progressive damage and failure of composite structures subjected to dynamic loadings (high velocity impact, blast) is controlled by the occurrence and interaction of multiple damage mechanisms; in composite laminates and sandwich systems, dominant mechanisms are multiple delamination of the layers, fracture at the core-face interface and core crushing. Understanding damage interaction effects and the complex nonlinear behavior up to failure of the composite systems is essential if they are to be used for load bearing applications, for instance in the naval and aeronautical industries. In addition, insight into the effects of damage progression and interaction is important for the formulation of global damage detection methods and health monitoring techniques or the design of structural control strategies. In the paper we recall some results of an extensive research program dealing with damage progression and failure of laminated composite and sandwich beams subjected to dynamically applied out of plane loadings. The results highlight some characteristic features of the response of damaged composite structures and suggest ways to improve structural performance and different key properties, such as damage resistance and tolerance and energy absorption, through the controlled design of the system.