Local Destroy Study Of Ship Structure Under The Loading Of Blast And Impact

The damage of warship under contact explosion is studied chiefly in this article. The major research areas of ship damage under contact underwater explosion include four sectors, namely, (1) the characteristics of fluid field disturbed by a contact explosion and loadings of contact explosion; (2) the analysis of transient fluid-structure interactions, and the corresponding dynamic responses of the ship; (3) propagation and attenuation of shock wave in multi-layer structure; (4)the dynamical plastic deformation response and damage analysis of ship hull subjected to contact explosion.Detonation products and blast shock wave destroy the ship hull together in conditions of contact explosion. Primary theory of detonation wave and plane shock wave is introduced then. Approximately calculation formula is presented. The necessary preparation is do for the analysis of ship hull damage under contact explosion.Evidently, extensive research on the damage effects of a ship arising from non-contact underwater explosions, as well as research on protect design of the shipboard equipments against the shock environment is of great importance in improving the survivability and battle capacity of the ship.The ship hull is mainly made up of girder and plate. The dynamic response of ship hull under contact explosion is emphasis of survivability. The plastic dynamic response is analyzed based on the postulate of rigid-perfectly plastic materials and energy principle in this article. The calculating method of damage parameter such as plastic deformation region and survival flections is reached. The result is compared with experiment and empirical relation. Neither strain rate sensitivity nor elastic effects are taken into account. The interactive effect of shear force and bend moment are not considered. Experiment result and numerical simulation proved the reliability and practicality of the simplification.The shipboard defense damage under explosion load is studied in this article. The multi-layers defense structure has great importance to diminish the damage of explosive shock wave. When calculate the initial parameter of air shock wave in the first cabin, the process is isentropic because reflective shock wave into defense structure is rarefaction wave. The calculation is simplified using shock adiabatic to replace isentropic of the reflected shock wave.For the complicated shell framework of the ship with strong-armor and unsymmetrical-structure, its distortion and breach under torpedo and missile can give only a simple description by analytical method in predigesting. The cost of experimentation is great high, and the numerical analysis is an effective and approximate means. The paper did the numerical research for the dynamics response of the shipboard framework under contact explosion, and computed respectively two groups of charge-weight in two different boundary conditions. The numerical results show that numerical simulation can describe the dynamics course and breach characteristic of the liquid and structure in nonlinear coupling response qualitatively and quantitatively. So the numerical simulation can apply to the analysis of structure breach in contact explosion.