Study On Characteristic And Equivalent Load Of Explosion In Cabin

Semi armor piercing anti-ship missile is the main threat of large ship.When Semi armor piercing anti-ship missile explodes in the cabin,the explosion shock wave and quasi-static pressure are the main damage loads.Unlike the explosion loads in the free field,the explosion loads in the cabin are very complex.In this paper,theoretical analysis,numerical simulation and experimental methods are used to study the characteristics of explosion load and equivalent load model in the cabin.The research work and conclusions of this paper are as follows:The characteristics of shock wave load and quasi-static pressure of cabin explosion are revealed.The cabin explosion test is carried out to verify the accuracy of finite element software Autodyn in simulating cabin explosion.The weight of shock wave load and quasi-static pressure load in the damage of cabin structure is studied by combining theoretical estimation and numerical simulation.The necessity of taking explosive shock wave and quasi-static pressure as the main research object in the study of implosion load is clarified.Abaqus external subroutine is compiled in FORTRAN language.The propagation process of shock wave is simulated by dimensionless parameters measured by outfield explosion test,and the load of implosion shock wave is simulated by using mirror explosion source three times in a row.The difference compared with Autodyn's fluidsolid coupling calculation is acceptable,but it greatly improves the calculation efficiency.The change of material yield condition during bulkhead deformation is analyzed by theoretical method,and the ultimate static collapse force of bulkhead under different transverse deformation is obtained by energy method,which serves as the basis for judging the end of quasi-static pressure action.Compared with the numerical simulation results,it is found that the overpressure equivalent model is more accurate than the traditional method,but it is still quite different from the actual one.Based on the U.S.standard implosion load calculation UFC-3-340-02,the total effective impulse of the cabin explosion load is analyzed,and the effective time of the cabin explosion load is obtained.The results are compared with the numerical simulation results.The results show that the effective time of cabin explosion is usually in the order of milliseconds,and the load model based on impulse equivalent can evaluate the in-cabin explosion load accurately.A large number of numerical simulations were carried out to simulate the damage of structures in cabin explosion,and the damage of different cabins under different case were obtained.Three kinds of holistic damage modes,i.e.large deformation,shear and tensile tear of cabins,were summarized.According to different damage modes,impact damage model and quasi-static damage model were proposed,which can be used to evaluate cabin damage of the structure under the effect of implosion.