Vibration And Noise Of Open Cylindrical Shell Under Plane Acoustic Excitation With Complex Damping Characteristics

The acoustic vibration coupling problem of shell structure plays an important role in vibration and noise reduction engineering.This problem has been paid much attention all the time and the related research has become an important part of the research on the coupling of vibration and acoustic vibration.Shell structure has been widely used in engineering.It is one of the important components of vehicle,highspeed train,ship and aircraft.It is of great significance to carry out the vibration,acoustic radiation and acoustic transmission analysis of typical engineering shell structures and explore the technical scheme to improve their acoustic vibration characteristics from the initial stage of design.In this paper,the basic theory of open cylindrical shell is introduced.An analytical model for calculating the vibration response and sound transmission of an open cylindrical shell under acoustic excitation is established.The research content of this paper includes the following parts:1.On the basis of Love theory,the natural frequency solution equation and response solution equation of the open cylindrical shell with four edges simply supported under harmonic excitation are derived,and the response characteristics of the open cylindrical shell with four edges simply supported under harmonic excitation are obtained through examples,including the relationship between the lengthdiameter ratio,thick-diameter ratio,opening Angle,damping coefficient and response.At the same time,the relationship between the response of different positions on the shell and the external load frequency is analyzed.2.Respectively establish plane sound wave excitation is only considered the response of open-end cylindrical shell analytical solution calculation model,considering opening plane sound wave and the reflected sound wave excitation,the response of the cylindrical shell analytical solution calculation model,considering plane waves,the reflection and radiation acoustic response analytical solution of open-end cylindrical shell calculation model,the acoustic excitation under the action of opening the response of the cylindrical shell under three different conditions,analyzes the different length to diameter ratio,thickness to diameter ratio,opening Angle,the relationship between the complex damping coefficient and response.3.The analytical calculation model of acoustic transmission,acoustic field,and acoustic pressure of an open cylindrical shell under acoustic excitation based on acoustic vibration coupling response is established.The internal and external sound pressure of open cylindrical shell with different structural parameters such as lengthdiameter ratio,thick-diameter ratio and opening Angle were calculated quantitatively.At the same time,the sound pressure distribution of the open cylindrical shell at different positions is calculated,as well as the sound transmission and sound power of the open cylindrical shell under acoustic vibration coupling.The influence of different structure parameters and damping coefficient on internal and external sound field and transmission is analyzed.