Full-field 3D deformation measurement of thin metal plates subjected to underwater shock loading

In this paper, the dynamic deformation of thin metal plates subject to underwater shock wave loading are studied by using high-speed 3D digital image correlation (3D-DIC). An equivalent device consist of a gas gun and a water anvil tube was used to supplying an exponentially decaying pressure in lieu of explosive detonation which acted on the panel specimen. The thin circular specimen panels with different support boundary conditions ware fixed on the end of the anvil tube by the flange ring cover. The thin circular plates with different thickness were made of pure copper. The intensity of impulsive loading is controlled by changing the impact velocity of the flyer. The pressure history of the underwater impulsive wave was measured by a pair of dynamic pressure transducers. The transient responses of the panels were measured by a High-speed three-dimensional Digital Image Correlation (3D DIC) photography system. The 3D DIC system records full field shape, displacement profiles velocity profiles and strain profiles of the specimen surface in real time. The influences of intensity of loading and support condition on the deformation of specimen panels are discussed based on the DIC results. The strain gauges also were used to monitor the structural response on the selected position for comparison. The DIC data and the strain gauges results show a high level of correlation, and 3D-DIC is proven to be an effective method to measure 3D full-field dynamic response of structures under underwater impact loading.