Dynamic response of circular composite laminates subjected to underwater impulsive loading

The dynamic response and failures of carbon/epoxy composite laminates subjected to underwater impulsive loading are investigated experimentally. The effect of impulsive intensity and thickness of laminates on dynamic deformation, failure modes, and associated mechanisms is identified and quantified respectively. The plates are subjected to underwater impulsive loads of different intensities with a lab-scaled underwater explosive simulator. 3D DIC is employed to capture the dynamic response in terms of response rate, mid-span deflection, and deflection-profile history during the elastic response process, followed by a series of postmortem non-destructive investigation and microscopic examinations to examine the failure modes and its distributions, and analyse the associated mechanisms. The results show that the intensity of impulse, thickness and failure of panels affect the dynamic response of laminate plates significantly. The non-surface failure has very limited influences on the tendency of the deflection-impulse relationship, and the local failure on the surface occurring later than the delamination and fiber fracture through the thickness of laminates. The blast resistance of composite laminates is not enhanced continuously with the increasing thickness due to the inconsistent changes of failure modes. With similar areal mass, meanwhile, composite laminates perform better blast-resistant performance than that of the metallic structures.