Vibration And Noise Characteristics Analysis Of The Cabin With Viscoelastic Damping Layer

The vibration and noise of ship cabin directly affect the comfort,the stability of structure and the reliability of equipment,which makes the vibration and noise of cabin highly concerned by the ship industry.Therefore,the analysis of vibration and noise characteristics of ship cabin becomes more and more important.This paper is based on ANSYS Workbench and Virtual.lab Acoustics software and vibration system control platform,the vibration and noise characteristics of the cabin with viscoelastic damping layer are analyzed.The main research contents are as follows:（1）Based on the CAD drawing of a ship cabin simulator,the three-dimensional structure model of the cabin is created through Solidworks software.The finite element model of the cabin is established based on the simulation software ANSYS Workbench,and the modal analysis is done to obtain natural frequencies and modal shapes of the first20 orders.The harmonic response of the cabin is analyzed,and the frequency response curve on the cabin wall is obtained.The sweep frequency vibration test is carried out,and the natural frequency results obtained from the test are compared with the simulation results to verify the correctness of the cabin finite element model and the accuracy of the modal simulation results.（2）Using the ANSYS Workbench platform,the dynamic model of the cabin with viscoelastic damping layer is established based on the finite element method.The vibration characteristics of the cabin with viscoelastic damping layer are analyzed and the harmonic response considering the frequency dependence of viscoelastic damping material is analyzed.The numerical calculation results of the cabin before and after laying viscoelastic damping layer are compared and analyzed.It is concluded that the damping layer material has a good damping effect on the cabin.The effects of viscoelastic material layer thickness and laying area on the vibration characteristics and response of cabin system are discussed.（3）The vibration test platform of cabin is built,and the cabin natural frequency before and after laying viscoelastic damping is tested by linear frequency sweeping method,and compared with the natural frequency calculated by finite element software;the constant frequency excitation response tests at different frequencies are operated before and after the damping layer is laid,the accuracy of the response calculation results is also verified.The effects of the laying area of viscoelastic damping layer and the excitation amplitude of shaking table on the cabin vibration control are analyzed and verified.（4）Based on acoustic theory and direct boundary element method,the acoustic boundary element mesh model of the cabin is created by Virtual.lab Acoustics.Using the cabin vibration response data calculated above as the boundary conditions,the acoustic simulation of the cabin before and after the installation of viscoelastic damping layer is carried out,and the frequency sound pressure curve of the field points in the cabin is obtained.The results showed that the noise of the cabin with damping layer is reduced by9.75 dB compared with that without damping layer,the feasibility of the viscoelastic damping layer material on noise reduction of the cabin is verified.