Research On Equivalent Target Of Marine Steel Invulnerability Analysis Of Warship

The research on the vulnerability of warship can not only grasp the vulnerability data of enemy warships,but also guide the research on the vitality of the warships of our country.Attacking vulnerable parts in combat can cause maximum damage to warships in the shortest time,and even achieve the effect of “turning defeat into victory”.Therefore,the research on the vulnerability of warship has important implications to the future naval warfare of our country.In this paper,the combination of experiment and simulation is used to study the establishment method of warship equivalent model.The research work are as follows:(1)In view of the research status of equivalent target and warship vulnerability at home and abroad,this paper analyzes the domestic and foreign research deficiencies,and puts forward the scientific problems.Secondly,the steps of vulnerability analysis are analyzed and summarized,and the general method of vulnerability model is given,including determining damage element,classifying damage level,establishing damage tree,simplifying the structure,equivalent method of vulnerable parts.Finally,the vulnerability of the ship was analyzed by taking the DDG51 destroyer as an example.(2)The static and dynamic mechanical properties of marine steel and equivalent steel(Q235)were tested.The mechanical properties of the two steels were analyzed based on the parameters(such as strength,modulus).The mathematical models of yield strength versus strain rate of two kinds of steels under dynamic loading were obtained by data fitting.The main parameters of the johnson-cook model of marine steel and Q235 steel were obtained based on the mechanical property experimental,and the accuracy of the parameters was verified.(3)Aiming at the two main damage elements of the warship,the equivalent relationship between the marine steel and Q235 steel under fragment penetration and shock wave damage is studied by the combination of experiment and simulation.When the fragment,the mathematical model of the ballistic limit velocity changing with the thickness of target was obtained through experiment and simulation.According to the equivalent principle of "the same ballistic limit velocity",the corresponding relationship between the thickness and yield strength of two kinds of steels was established,and the equivalent coefficient was obtained.When the shock wave,the target undergoes "concave" plastic deformation under a certain dose.The mathematical model of the deflection of target with the dose is obtained through experiments.According to the equivalent principle of "the same deflection",the corresponding relationship between deflection and yielding strength of two kinds of steels are obtained,and the equivalent coefficient was obtained.(4)According to the results of the previous study,the equivalent target calculations were carried out for each consumable part of the DDG51 destroyer.And the vulnerability equivalent model of DDG51 was established in the "Vulnerability Modeling" software.