Research On Damage Process Of The Warship Broadside Multicamerate Defence Structure Subjected To Underwater Contact Explosion

In the sea warfare,the Large-scale warship will face shock of underwater contact explosion inevitably.There is a fact that underwater explosion has a more destructive effect than aerial explosion.It will cause wide range wreckage,damage to the internal equipments and casualties if the structures of warship broadside are hit directly,resulting in the ship lost combat effectiveness or even sank.The large-scale warships often cost large space to improve the protective performance.The warship broadside multicamerate defence structure is set to reduce the destructive effect layer by layer.Therefore,research on damage process of the warship broadside multicamerate defence structure subjected to underwater contact explosion is of great importance to evaluate the ship’s survivability,to improve the protective performance and to design the new type of warship broadside multicamerate defence structure.Based on theory of underwater explosion and numerical simulation of underwater shock wave,numerical simulation of the typical multicamerate defence structure is studied and compared with the results of literature test,determining the numerical simulation method with multi-Euler soild-fluid interaction.The influence of explosion vent hole and liquid ratio on the protective performance of the warship broadside multicamerate defence structure is studied by using the transient dynamic analysis software.Based on the failure mechanism of the warship broadside multicamerate defence structure,sensitivity of the inner shell of the liquid tank is analyzed,and structures with high sensitivity are determined.The dynamic responses of the warship broadside multicamerate defence structure with different explosives and thickness of the shells are analyzed systematically,and the dynamic response variation law of the multicamerate defence structure is obtained.Finally,formulas for predicting the damage and energy absorption of the warship broadside multicamerate defence structure subjected to underwater contact explosion are proposed,and the rapid damage and specific energy absorption prediction of warship broadside multicamerate defence structure is realized.Size optimization and numerical simulation validation is studied to the warship broadside multicamerate defence structure and the best bulkhead thicknesses are gained.A new warship broadside multicamerate defence structure with different forms of the clapboard is designed and compared with that of typical warship broadside multicamerate defence structure,and the conclusion is obtained that the protective performance is better.The main research contents are listed below:(1)Theory of shock wave underwater explosion and its simulation method validation are studied.The propagation process and parametric equation of the shock wave and detonation wave are studied firstly.Contrasting peak pressurees with the empirical formula,the finite element mesh sizes with satisfied calculation accuracy are gained as well.Based on the results,by using numerical simulation method with multi-Euler soild-fluid interaction.numerical research on typical multicamerate defence structure is studied and the simulation method is verified by contrasting with the experimental results.(2)Research on protective properties of the warship broadside multicamerate defence structure.Firstly,the influence of explosion vent in the expansion tank and liquid’s proportion in the liquid tank on the protective performance of the warship broadside multicamerate defence structure is studied.Secondly,the dynamic response of the warship broadside multicamerate defence structure subjected to underwater contact explosion is studied,and the failure mechanism of each structure is revealed.Finally,by changing the liquid ratio in the liquid tank,the effects of different liquid ratios in the liquid tank on the protective properties of the warship broadside multicamerate defence structure are studied,which lay the foundation for determining the form of the warship broadside multicamerate defence structure.(3)Research on dynamic response of the warship broadside multicamerate defence structure.In order to study the influence of explosives and thickness on the protective performance of the warship broadside multicamerate defence structure,the sensitivity of the inner shell of the liquid tank is studied firstly.Based on the failure mechanism of the warship broadside multicamerate defence structure,the shells with great influence on the protective performance are revealed.Finally,the transformation laws are gained by analyzing the results of numerical simulation.(4)Research on damage and energy absorption prediction formula of the warship broadside multicamerate defence structure.Based on results of numerical simulation,the formula of damage prediction of the warship broadside multicamerate defence structure is obtained through the coupling action.According to the regulation of energy absorption response,the formulas of specific energy absorption prediction of the side plate,the clapboard and the outer shell of the liquid tank are put forward.(5)Research on optimization of parameters of the warship broadside multicamerate defence structure.Based on the formula of specific energy absorption prediction,the mathematical model of size optimization is established,and the thicknesses of the expansiontank is optimized.A new type of warship broadside multicamerate defence structure is proposed,and its dynamic response are compared with the traditional warship broadside multicamerate defence structure.