Research On Impedance Matching Design Of Ship Base

The pedestal structure is the main carrier of various types of machinery and equipment of the ship.During the voyage,the hull structure is inevitably subjected to the excitation load of various complex mechanical equipment.The vibration energy is transmitted to the hull through the pedestal,causing the hull to generate various forms of vibration.Failure to take effective control measures will affect the overall level of vibration and acoustic radiation of the ship and the comfort and safety of the ship.Due to the large scale of the ship's structure and the complicated internal structural forms and component arrangements,it is relatively difficult to control the vibration transmission path.Therefore,in order to achieve the purpose of reducing vibration and noise,it is more effective to reduce the vibration energy input to the supporting structure such as the base.Measures.In order to reduce the vibration and acoustic radiation of ship structure,this paper adopts theoretical analysis,numerical calculation,experimental verification and other methods.Following the idea of combining with engineering application,the research and analysis of impedance matching design of ship base is carried out.Firstly,the relationship between the design of low-radiation noise ships and the impedance of the pedestal was introduced by consulting relevant literatures.At the same time,the research status of the pedestal structure impedance,especially the characteristic parameters of the pedestal structure,the structural form,and the connection with the hull Influence of foundation impedance and acoustic and vibration characteristics of ship structure.Thus,the main research content and direction of this paper were determined,which laid the foundation for the subsequent work.In order to determine the requirements for the base impedance of low-noise ships,this paper takes the "equipment-base-hull structure" multi-degree-of-freedom coupling vibration system as the research object,and analyzes the unbalanced disturbance force,unbalanced disturbance torque,and unbalanced shock The excitation of the foundation under the load of three typical equipment such as the combined action of disturbance and moment.From the perspective of impedance analysis and numerical calculations,the vibration and sound radiation of the hull structure are taken as the assessment.The corresponding relationship of vibration and acoustic radiation clarifies the design direction of the impedance matching of the base of the low-radiation noise hull structure under the typical excitation load.Based on the comparison of the vibration and acoustic radiation characteristics of the ship's cabin structure reference model,based on the acoustic-solid coupling method,the design variables such as the base structure form and characteristic parameters were explored from the aspects of vibration characteristics and radiated noise characteristics.The influence rule of characteristics,clarifies the relationship between the base impedance and the structural characteristic parameters,and lays a foundation for the establishment of the impedance matching design method of the ship base structureOn the basis of the above study,the method of impedance matching design for ship bases is summarized,and the corresponding design process is formed.In order to prove the effectiveness of the design method described in this paper,a verification test of the impedance matching design of the base under the effect of unbalanced disturbance was carried out,and the transfer function test of the cabin structure was carried out.The test results and numerical analysis results fully verified the validity of the design.Finally,the actual effect of the design method in real ship applications is analyzed,and the impedance matching design of the surface ship propulsion motor base is carried out.According to the equipment load characteristics,the corresponding base structure design scheme is proposed.The results show that the design method in this paper meets the requirements for improving the acoustic and vibration characteristics of ship structures,and achieves the goal of low-noise design of ship structures in the design stage.This paper explores the relationship between the design of low-noise ships and the impedance of the pedestal,summarizes and summarizes the influence rules between the pedestal impedance and the structural characteristic parameters,and initially establishes the impedance matching design method of the pedestal of the ship,and conducts validation tests.The analysis of actual ship application effects provides a certain reference value for practical engineering applications of impedance matching design of ship bases.