Simulation Research On Vib-acoustic Characteristics And Active Control Of Cylindrical Shell Coupling Structure

Cylindrical shell has been widely used in engineering practice. The vibration of theinternal mechanical structure of cylindrical shell usually makes the cylindrical shell structureproduce a strong vibration and noise, while, these vibration and noise are not acceptable forpeople. So, for cylindrical shell structure, there is a very important significance to studyvib-acoustic and noise control problems. For the vib-acoustic of cylindrical shell structure,there are lots of work has been done both in domestic and abroad, and lots of works have alsobeen done in the area of vibration-acoustic radiation. However, it still do not meet therequirements. So, how to reduce the vibration and the radiated noise of cylindrical shellstructure is still touted by the majority of scholars. In this paper, vib-acoustic characteristicsand the control problem of both stiffened-cylindrical shell and the system which made up bystiffened-cylindrical shell and vibration isolation structure by simply supported at two endsare studied.Firstly, the article derives the acoustic radiation mode theory of cylindrical shell bysimply supported at two ends, the far-field acoustic radiation modes of cylindrical shellstructure based on the acoustic radiation mode theory is derived. The previous order acousticradiation modes and the order acoustic radiation modes corresponding radiation efficiency aresimulated and analyzed in this article, and the acoustic radiation chatacteristics of cylindricalshell is also researched.Then, this article is based on the acoustic radiation mode theory and deduces thevib-acoustic characteristics of stiffened-cylindrical shell. The article analyzes the acousticradiation mode of stiffened-cylindrical shell, and analyzes the influence of vib-acousticcharacteristics of stiffened-cylindrical shell when the number and size of the ring rib ischanged. And the aritcle is based on the acoustic radiation mode theory researches theacoustic radiation chatacteristics of stiffened-cylindrical shell.In order to make the vib-acoustic of stiffened-cylindrical shell obtain a better control, thearticle based on the above researches builds up mathematical model of the coupled systemmade up by stiffened-cylindrical shell and passive vibration isolation structure. Based on thetheory of power flow, this article deduces the power transmission which through isolationsystem into stiffened-cylindrical shell. Under the condition of different parameters, the power transmission of coupling system is simulated and analyzed.Based on the coupled system above, the mathematical mode of the active vibrationisolation coupled system is established. Finally, in the condition of on the acoustic radiationmode theory, the optimal control forces of stiffened-cylindrical shell and active vibrationisolation coupled system are derived, and the acoustic radiation power of the two systems iscontrolled by different control strategies, then the results have been analyzed.