An experimental methodology to study impulsive hydrodynamic loading of air-backed composite plates

Sandwich composites in marine vessels are frequently exposed to impulsive hydrodynamic loading during operation in extreme environments. The response of sandwich composites to impulsive hydrodynamic loading has yet to be fully investigated due to the lack of full-field, simultaneous measurement techniques. Here, we propose an experimental framework for the study of the dynamic response of sandwich composites to hydrodynamic loading. We focus on a fiber-reinforced plate positioned at the air-water interface subjected to impulsive hydrodynamic loading. The interaction between the plate and the water is studied through a combined visualization technique based on particle image velocimetry (PIV) and digital image correlation (DIC). The velocity and pressure fields are quantified through PIV, and, simultaneously, the out-of-plane vibration of the plate is inferred from DIC. Repeated measurements were conducted for a range of hydrodynamic loading conditions. Our experiments unveiled a rich multimodal response that is strongly coupled with the flow physics. This work constitutes a first step toward an experimental understanding of fluid-structure interaction of air-backed sandwich composites.