Research On Vibration Characteristics Analysis And Modal Matching Of Key Components Of Large Caliber Naval Gun

Modern large caliber naval gun weapons have the characteristics of low launching cost,fast firing speed and short combat preparation time.However,the characteristics of high firing speed and high impact will inevitably lead to the increase of dynamic load.The greater the dynamic load,the greater the impact on the firing accuracy and stability of naval gun.Therefore,it is very important not only to consider the static characteristics of key components of naval gun launching system,but also to analyze its dynamic characteristics.In this paper,the vibration of barrel,cradle and bracket,which are the key components of naval gun launching system,is studied.The vibration characteristic analysis of each key component is mainly completed,and on this basis,the dynamic analysis,modal matching optimization and reduced scale modal response test of each key component are carried out.First,the barrel,cradle and bracket are reduced to the frame structure composed of space beam units.The stiffness matrix,mass matrix and damping matrix of the space beam unit are derived;the overall stiffness matrix of the finite unit method,the simplified structure of the barrel,cradle and bracket structure are analyzed by Ansys Workbench software,and verify the correctness of the original structure to the space beam structure.Secondly,the transient vibration displacement,velocity and acceleration response of the barrel,cradle and bracket were solved by using the Newmark-β method.The main structures of the barrel,cradle and bracket are grid divided,and the collision finite element modeling between contact surfaces to calculate the main excitation load of the ship gun.Based on the harmonic response analysis,the Modal module and the Harmonic Response module,with the purpose of exploring the impact of the frequency of the resonance on the structure,and then improve the accuracy and continuity of the gun.The second-order polynomial function expression of the muzzle acceleration response based on the response surface method and the optimization results by ANOVA and correlation analysis verify the feasibility of the approximate model.The vibration acceleration of the muzzle combined with the satisfaction function method was optimized to obtain the best frequency matching scheme of the barrel,cradle and bracket structure,and minimize the vibration acceleration response of the muzzle.According to the optimal frequency matching scheme,the topological structure optimization of the barrel,frame and carrier,and compared the optimized structure with the optimized previous structure,verified that the response of the optimized ship gun port is reduced significantly,indicating that the best frequency matching scheme is effective.Finally,the mode test and vibration response experiments are conducted on the ship gun cradle and bracket scaled model,and we compare the experimental results with the Ansys simulation results to verify the similarity of the inherent modes,which is then used to predict the modal properties of the original structure.