Research On Response Simulation Of War-Ship Broadside Procective Structure Under Inner Explosion

In modern naval battle,warship is more likely to be attacked and badly destroyed as anti-ship weapon is equipped with higher hitting precision and stronger exploding power.The self-protective structure of ship is the last line of defence,whether the protective structure is safe has direct relation to the vitality of warship.The present paper,with its focus on dynamical response of multi-layer protective structure of side of large surface ships under inner explosion of anti-ship weapon,researches on the issues through theoretical analysis and numerical simulation.The main work will be introduced in following 4 aspects:(1) Research on production of air blast shock-wave and its propagation rule.The non-liner transient dynamical software MSC.DYTRAN is used to simulate the whole propagation process of explosion shock wave.Numerical results are in agreement with experimental results.Feasibility and accuracy of the seftware are proved.Effect of different state equations of detonator on the results of explosion shock wave in the air is discussed and the conclusion is reached that it is feasible to simulate the detonator as a gas ball with high pressure and high precision results is reached if Gamma rule state equation and ROE solving module are used.(2) Based on proper assumption,a theoretical formula is deduced which expresses the dynamic response of plate frame under shock wave.Meanwhile,a simulation example is given and the results are compared with the experiment results in associated literature.Considering the characteristic that anti-ship weapon attack warship,loading area of the plate frame is studied.Then,plastic response mode of stiffened plate under explosion shock wave loading is simulated using proper finite dement model.(3) The failure of broadside protective structure under explosion load is studied and the explosion process of anti-ship warhead inside of the vessel is numerically simulated.The failure mode of cabin structure under explosion load is analyzed and pattern of conner strengthening with better blast resistance behavior is presented. (4) The dynamic process and failure characteristic of the response coupling fluid and structure nonlinearly under100kg TNT explosion is simulated.Based on the analysis,the proper protective structure is put forward.It will decrease the propagation of shock wave into the inner cabin if proper excretory hole is arranged in excretory cabin and shock wave is guided to propagate along vessel longitudinally.(5) The explosive process of the fragments produced by the coupling of detonator and shell structure is simulated.The distribution law and velocity of fragments after explosion of anti-ship warhead and the strength of shock wave considering the energy of fragments is analyzed.It is concluded that the fragments with small mass between 0.1g and 1g are in the majority;the velocity of fragments is between 2240 and 2334m/s regardless of the mass of fragments.Under this condition, the protective structure should prevent the impact failure of fragments with mass larger than 100g.To some extent,the conclusions and suggestions given in this paper is a valuable reference to anti-explosion research and structure design of ship.