Analytical Puncture Study of Circular Metal Plates

An existing closed-form solution for large-deflection static responses of centrally loaded, rigid, perfectly plastic circular metal plates (with emphasis on steel plate cases) that are clamped (built-in) or simply supported at the edges is first modified to take into account the effects of elastic deformation and material strainhardening in an approximate manner. The modified theoretical solution is first shown to correlate very well with experimental results. Then it is applied in solving the quasi-static plate puncture problem in which the punch bar penetrates slowly into the plate. An analytical/experimental correlation study on punch force-deflection relationship and incipient plate puncture energy is made on newly obtained experimental data. Effects of variation of strainhardening parameter, boundary conditions and shear deformation on incipient puncture energy are studied, and plate puncture design curves are developed in the form of nondimensional incipient plate puncture energy as a function of punch diameter/plate thickness ratio for various values of punch diameter/plate diameter ratio. Application of these analytical techniques/design curves to the design of nuclear shipping cask plate components subject to regulatory puncture drop loading is also discussed.