Research On New Type Of Vibration Damping Structure Based On Acoustic Black Hole Effect

Acoustic black hole structure is a kind of wave trap made by changing the structural form.Through the diversification of the structural impedance,the wave velocity changes and the vibration energy is concentrated in the local region,achieving efficient control of structural vibration.At present,the change of structural impedance is mostly realized by reducing the thickness of the structure.The manufacturing method of the traditional ABH has greatly damaged the strength of primary system and its characteristic frequency is dependent with its size,which limits its application in practice.In this paper,a new type of vibration damper is proposed based on the combination of acoustic black hole effect and the principle of dynamic vibration absorption,which overcomes the defect of insufficient strength and broadens effective bandwidth of the traditional one.In addition,the proposed design possesses the capability of dynamic vibration absorption without complicated parameter design.The main contributions of this paper include:(1)The design method of the acoustic black hole damper(ABH damper)was proposed,and the advantages of ABH damper were pointed out.Taking plate-like structure as an example,the broadband vibration damping characteristics of ABH damper were verified by comparison of ABH damper and equal mass damper(EM damper).Besides,the internal mechanism of the ABH damper was revealed.Then based on the power flow and vibration damping theory,the energy concentrating and vibration suppression advantages of the designed damper were analyzed,and the damping mechanism was further explained.(2)The trend of acoustic black hole effect of the ABH damper with variable power and truncated thickness was studied.Also,influence of dimensions,distribution locations and the quantity on the overall damping characteristics of the structure were explored,and an optimized design was proposed.(3)Application potential of ABH damper in plate vibration control was studied by experimental means.The mobility and mean square vibration response were used as indicators to evaluate the influence of physical parameters on the broadband vibration damping characteristics of ABH damper.Furthermore,the experimental investigation on the ABH damper shows rationality of the damper designed in this paper and its broad prospects in practical engineering applications.