Research On Vibration Characteristics And Shrinkage Ratio Experiment Of The Large Caliber Naval Gun Key Components

With the development of ship gun design to high speed,large scale,light weight and complexity,it is more and more important to analyze the vibration characteristics of ship gun.The design of ship gun should not only consider static characteristics,but also consider the overall dynamic characteristics.Therefore,this paper studies the vibration characteristics of the key components of large caliber naval gun: cradle and bracket.First of all,based on the vibration theory of continuous plate,the field transfer matrix of out-of-plane and in-plane vibration of the plate element is established;the line transfer matrix at the coupling boundary of the coupling plate and the displacement continuity condition are derived,and the point transfer matrix at the coupling boundary of the coupling plate is established by force balance condition;The integral transfer matrix of the cradle and bracket system is established by multiplying the transfer matrix of each unit of the key parts of the ship gun,and the natural frequency and mode are obtained by substituting the actual boundary conditions of the cradle and bracket.At the same time,the method of solving vibration response of cradle and bracket is given.The correctness of the theoretical method is verified by three examples and compared with the results obtained by finite element method.Secondly,based on the three theorems of similarity theory and the derivation method of similarity criterion: dimension analysis method and equation analysis method are used to calculate the shrinkage ratio relationship between the modal parameters of the original model and the shrinkage ratio model of the key parts of the large caliber naval gun,and the results obtained by the finite element method are compared.It is proved that the shrinkage ratio relationship obtained by the theoretical calculation is correct,and the shrinkage ratio model of the key parts of the naval gun-bracket is manufactured.Finally,modal analysis and vibration response experiments are carried out on the model of key components of naval gun,and the results obtained by the experiment are compared with the results calculated by the transfer matrix method,which proves the correctness and practicability of the theoretical method.At the same time,the experimental verification of the shrinkage ratio relationship between the original model and the shrinkage ratio model of the key components of the naval gun is carried out.It is proved that the shrinkage ratio relationship obtained by the theoretical calculation is correct and can be applied in practical engineering.Therefore,the vibration characteristics of the original model can be estimated by analyzing the vibration characteristics of the shrinkage ratio model of the key components of naval gun.