Research On Vibration Characteristics And Structure Optimization Of Cradle Of Large Caliber Naval Gun

With the advancement of science and technology,the defense military system is becoming more and more powerful.The caliber of modern naval guns is gradually increasing,with a longer range and higher precision,which is bound to have higher requirements on the structure of the naval gun itself.At present,research on typical components of naval gun has become the focus of the large-caliber naval gun design.In this paper,the structure of the cradle of large-caliber naval gun is studied.This paper mainly analyzes the motion characteristics of the cradle of large-caliber naval gun.On this basis,carrying out the vibration reduction design and structural optimization of the rocker are carried out.Firstly,the force analysis and motion characteristics of the large-caliber gun cradle are analyzed.The launching principle of large-caliber guns was introduced.The cradle of large-caliber guns was selected as a typical component for analysis.The stress of the cradle during the launching of the guns was analyzed.On this basis,a coordinate system describing the cradle motion was established,and the equations of motion and dynamics were derived.Then,the finite element analysis of the cradle is performed by using ANSYS/Workbench software.The structure was simplified according to the actual three-dimensional model of the cradle structure.The transient analysis of the cradle was carried out to obtain the stress at the joint between the cradle and the bracket and the displacement on the cradle.And the static analysis and modal analysis of the cradle were performed.The stress distribution in the launching process of the gun and the natural frequency and vibration mode of the cradle were determined.The part to be damped in the cradle structure is the diameter barrel part of the cradle,and the part to be optimized is the rear frame part of the cradle.Thirdly,the vibration of the cradle is suppressed by installing a dynamic vibration absorber.The mathematical model of the traditional vibration absorber was analyzed,and the principle of the dynamic vibration absorber was introduced.The diameter of the cradle was simplified to a cantilever beam structure,and the transverse vibration equation and torsional vibration equation were established to analyze the vibration characteristics.The vibration equation of the cradle with dynamic vibration absorber was established,and the displacement response of the cradle structure was analyzed.A dynamic vibration absorber was installed on the diameter of the cradle in order to reduce the vibration of the cradle.The Matlab program was written to find the optimal position of the dynamic vibration absorber and determine the parameters of the dynamic vibration absorber to achieve the optimal vibration reduction effect.Finally,based on the finite element analysis,the ANSYS/Workbench software is used to optimize the structure of the large caliber gun cradle.Firstly,three topology optimizations were performed on the rear frame of the cradle.The preliminary structure of the cradle was summarized.And then the precise structure size of the cradle was obtained through size optimization.The sensitivity analysis and response surface analysis were also performed.After two optimizations,the final structure of the cradle was obtained and the weight was reduced,the performance of the cradle was also improved.