Research On Vibration And Acoustic Radiation Of Periodically Distributed Double-Damping Plate Structure

Metal plate structure is a commonly used engineering structure,which is widely applied in civilian and military industries,such as automobiles,ships,aircrafts and other fields.As one of the passive noise and vibration control technologies,the periodic damping structure has not only the characteristics of low cost,easy operation,obvious effect of vibration and noise reduction,but also shows special structural advantages in low frequency vibration and noise radiation suppression,thus favored by researchers.Basing on the basis of preliminary laboratory research and the results obtained,the structure forms of periodic damping is further explored,and the periodic double-damping structure is proposed.The vibration and sound radiation characteristics of the structure are studied by using relevant theories and tools in order to further enrich and optimize the research and application of periodic damping structures in structural vibration and noise reduction area.There are many forms of periodic damping structures.This paper focuses on the application of the most common one-dimensional bar-cycle periodic double-damping and two-dimensional block periodic double-damping in thin plate structures.The effects of different structural parameters on the vibration and sound radiation characteristics of periodic double-damping are analyzed.Firstly,theoretical model of one-dimensional bar-cycle periodic double-damping plate structure and two traditional large-scale damping plate structures were established.The finite element method and the boundary element method are used respectively to calculate their vibration displacement response and field radiation sound power.Accordingly to the results,vibration and noise reduction effect of one-dimensional bar-cycle periodic double-damping laying way is significantly better than that of two traditional large-scale damping.Basing on this,the acoustic and vibration characteristics of one-dimensional bar-cycle periodic double-damping plate structure were studied.The influence of the structural parameters,such as damping laying rate,damping thickness and lattice constant on the acoustic and vibration characteristics of the structure was analyzed,and the influence curve of each parameter is also given by RMS handling on radiation sound power.Secondly,theoretical and simulation models of two-dimensional block periodic double-damping plate structure,two traditional large-scale damping plate structures and plate structure were established.The vibration displacement response and field radiation sound power of the structures were compared with each other respectively.The results show that the acoustic and vibration characteristics of two-dimensional block periodic double-damping plate structure are the best.Basing on this,the acoustic and vibration characteristics of two-dimensional block periodic double-damping plate structure were studied.The influence of the structural parameters,such as damping laying rate,period number and damping thickness on the acoustic and vibration characteristics of the structure was analyzed,and the influence curve of each parameter is also given by RMS handling on radiation sound power.Finally,the Danish B & K equipment was used to test the acceleration transfer function and the sound pressure value of the test plate with periodic double-damping structure to verify the relevant conclusions.