Design And Development Of Additional Vibration Absorber Based On Acoustic Black Hole Structure

Acoustic black hole(ABH)structure can reduce the velocity of bending wave and control the bending wave in the structure.Based on this characteristic of acoustic black hole,the traditional method is to embed the acoustic black hole structure in the plate.This method has some problems,such as difficult processing and damaging the structure of the plate.Aiming at the limitations of the traditional acoustic black hole structure,this paper designs an additional acoustic black hole vibration absorber structure,which also has certain vibration damping performance and can retain the overall strength of the controlled structure.The main contents and innovative achievements of this paper are as follows:Firstly,the basic damping mechanism of acoustic black hole structure is analyzed by geometric acoustic method.Based on finite element structural dynamics simulation method and vibration power flow theory,two forms of acoustic black hole absorber structures are designed,and the finite element model of additional acoustic black hole absorber plate composite structure is established.The suppression effect of concave and convex acoustic black hole absorber on bending wave and the aggregation effect on vibration energy are studied.The calculation results show that the acoustic black hole absorber can effectively reduce the vibration level of the thin plate,and has a good vibration reduction effect in a wide frequency range.Secondly,for the pit type vibration absorber with better vibration damping performance,this paper optimizes the model from two aspects of structural parameters and connection relationship,and analyzes the influence rules of acoustic black hole structure cut-off thickness,ABH part length and extension part length on the vibration damping performance of the vibration absorber.Three connection modes,offset connection,array connection and nested connection,are proposed,and the improvement effects of the three improved schemes on the vibration damping performance of the original scheme are compared.The results show that the reasonable design of structural size parameters can optimize the action frequency band of the vibration absorber,and the selection of appropriate connection mode can improve the vibration reduction effect of the vibration absorber.Finally,the application of acoustic black hole absorber in a diaphragm vacuum pump is studied,the scheme of acoustic black hole absorber for the bottom plate of diaphragm vacuum pump is designed,and the finite element model is established.The simulation results show that after the vibration absorber is installed,the vibration acceleration level of the foot of the diaphragm vacuum pump is reduced by 2.1d B at 10-315 hz and 3.0db at 10-8khz.It has a good damping effect in the whole frequency band.In this paper,an additional vibration absorber based on acoustic black hole structure is designed,its function of restraining vibration and absorbing energy is analyzed,the influence of different structural parameters and connection modes on its performance is discussed,and the feasibility of reducing plate vibration in engineering is verified,which has theoretical guidance and practical application value for the development of structural vibration control field.