Research On Damage Mode And Mechanical Criterion Of Ship Cabin Explosion

With the development of anti-ship missile weapon's armor piercing efficiency and navigation system,the ship's function cabin has become the target of precision strike.However,there is no unified standard for the assessment of the damage effectiveness of anti-ship missiles in China,and there is no systematic research combined with the target characteristics of ships.Under the action of explosion in cabin,these basic marine components of anti-ship missile will produce a large plastic crack area under the action of explosion overpressure and quasi static pressure,and even local fracture will form a crack,thus losing the bearing capacity of hull strength.Although the research on explosion in cabin has a long history,its damage mechanism is still not thorough.Therefore,it is very important to study the damage mode and mechanical criterion of ship structure under internal explosion load for damage assessment and protection structure design.The dynamic response of ship structure under internal explosion load is a complex nonlinear problem,and different cabin structures and reinforcement arrangements are also different,so it is very difficult to solve such a complex model accurately.In this paper,based on the failure modes of the cabin and the plate structure,the boundary conditions and the location,nine damage modes of the cabin implosion are proposed.Based on the large-scale cabin section implosion test and the related domestic and foreign implosion damage test,the possible damage modes are analyzed.In order to ensure the reliability of the following numerical conditions,we need to study and analyze the typical damage model by numerical simulation.The verification parameters are based on the acceleration signal,wall pressure load and the final damage break of typical working conditions,and the implementation method of numerical simulation is modifiedThis paper focuses on the mechanical analysis and criterion research of small deformation damage mode and large break damage mode under the internal explosion and internal explosion load of small cabin.The damage mode of cabin implosion is based on the plate frame structure of the hull,which is simplified as the equivalent plate beam element structure.Through the plastic dynamic analysis of small deformation damage mode and large break damage mode,the corresponding refined damage mode can be obtained.The criterion conditions and the accuracy of prediction formula are further verified by ale numerical method.Finally,the accuracy of the criteria and prediction conditions of this method is verified by the related cabin implosion test.The story height of the large channel can generally reach the height of two to three typical small cabins.When the structure size of the plate frame is large and the pressure relief area is large enough,the wall pressure load of the plate frame subjected to impact can ignore the follow-up quasi-static pressure load and the large proportion distance belongs to the category of near-field explosion or contact explosion.Therefore,the propagation process of the blast wave is based on the spherical radiation surface.In this paper,the response assumption is proposed for the explosion environment in the large channel.Based on the plastic dynamics,the criterion conditions of the typical hull plate frame structure are analyzed,and the corresponding prediction formula of the breach is proposed.The impact response of the test beam structure under the explosion impact load is analyzed by the numerical method,including the center deflection of the impact beam,the critical impact angle,and the material fracture strain And the plastic zone range,under the condition of satisfying certain accuracy,to verify the accuracy of theoretical prediction.Based on the hull mechanics model and the structural form of the equivalent slat beam,the relevant measuring device of structural fracture strain is designed,and the deflection impact response of the plate frame structure is taken as the measurement standard,the equivalent method of high-strength hull steel and common steel is proposed.