Dynamic response of copper plates subjected to underwater impulsive loading

Understanding the mechanical response and failure behaviors of thin plates under impact loading is helpful for the design and improvement of thin plate structures in practical applications. The response of a copper plate subjected to underwater impulsive loading has been studied in fluid-structure interaction (FSI) experiments. Three typical copper plates, (a) without a pre-notch, (b) with a cross-shaped pre-notch (+), and (c) with a ring-shaped pre-notch (#) were selected. A high-speed photography system recorded the full-field shape and displacement profiles of the specimens in real time. The 3D transient deformation fields' measurements were obtained using a 3D digital image correlation (DIC) technique. Strain results from DIC and the strain gauges technique were in good agreement. A dimensionless deflection was used to analyze the effect of plate thickness and loading intensity on the deformation of the copper plates. The typical failure modes of different copper plates were identified. The test plates exhibited large ductile deformation (mode I) for copper plates without a pre-notch, and large ductile deformation with local necking (mode Ic), splitting (mode II), splitting and tearing (mode IIc), and fragment (mode III) for the copper plate with a pre-notch.