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This and the next 2 slides are from:
Hans U. Mair (1), Hanson Huang (1), Bernard J. Andrys (2) and Michael E. Giltrud (2)
(1) Research and Technology Department, Naval Surface Warfare Center, USA)
(2) Advanced Technology and Research Corporation, USA
“Lagrangian hydrocode modeling of underwater explosive/target interaction”, 61st Shock and Vibration Symposium, Vol. V, NAVSWC MP 91-120, pp 79-89, 1990
ABSTRACT: Preliminary results are described for an application of the Lagrangian hydrocode DYNA3D in modeling the early-time interaction of an underwater close-in explosion with an externally stiffened, curved plate. The problem was terminated when element distortions reduced the time step to unacceptably small values. The Johnson-Cook constitutive and damage model was used for the steel plate and stiffener frames. Use of this material model allowed the frames to fail at their base and separate from the plate, relieving the stress in the target plate. Failure in the steel plate was shown to initiate directly under the explosive charge, but model improvements may alter this result. Shell elements were employed for the steel to properly model bending of the plate and frames, and to decrease problem size. A total of less than ten thousand elements (continuum and shell) were employed in the complete model; this was made possible largely through the use of non-reflecting boundary conditions.
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