The Destroy Analysis Of Ship Plate And Shell Structures Under Contact Explosions

The damage of plate and shell structures subjected to the striking loads and explosions was a very complex process with highly nonlinear character. With the development of the aggressive weapon, the thorough research on this problem was really important. The damage of warship subjected to contact explosions was carried out in this article with the theoretical analysis method and the numerical simulation method.The model of the clamped circular membrane which subjected to transverse contact explosions in the central was set up and the momentum equation and the initial boundary condition were also analyzed. In order to get the closed solution, the certain hypotheses were introduced and the initial boundary condition was simplified. All possible shock waves, rarefaction waves, and acceleration (second order wave) were completely analyzed. In the different phases of the shock wave and the different region of the plate, utilizing the wave equation the wave solution of the all region in the circular was calculated.The local ductile fracture criterion for uncracked in ductile material was adopted. It was assumed that fracture initiated at the critical point of structure when the accumulated equivalent plastic strainεwith a suitable weighting function reached a critical value. Then using the initialized parameters, the impulse in the unit area of the circular plate was calculated. Making use of the plastic dynamic response and the fracture criterion of plates subjected to explosions, the maximum slope of distortion in the plate was obtained and the critical blasting charge and critical deformation when the circumferential fracture was occurred at the invariable radius r were derived.Theoretical calculated results through an example were compared with the experiment results in the published literature, and they were almost coincided. It could be seen that the method of this paper could perfectly solve the dynamic fracture of thin plate under contact explosions. The analysis was done by the finite element software LS-DYNA, and it was compared with the result of the theoretical computation. It was indicated that numerical simulation could well analyze the plastic dynamic response of the plate which subjected to explosions.