Design Of Dynamic Absorber Based On One-Dimensional Acoustic Black Hole And Vibration Control Of Plate Structure

Acoustic black holes have a wide range of applications in structural vibration control problems because of their broad frequency and efficient vibration control capability and their simple and easy to implement structure.However,the practical application of acoustic black holes is usually achieved by cropping the thickness of the main structure according to a certain power function,which often affects the strength of the main structure,and there are disadvantages of acoustic black holes with high vibration control frequencies,which limit the development of acoustic black holes applications.Dynamic vibration absorbers are also commonly used in engineering as a means of vibration control,and they have good results for low frequency vibration control problems,but there are problems such as narrow vibration control bands and low control robustness.In this thesis,a 1D acoustic black hole dynamic absorber(1D ABH-DVA)is designed by combining acoustic black hole structure and dynamic absorber principle.The GEM method is used to establish a one-dimensional structure.The dynamics of a one-dimensional acoustic black hole beam is modeled by the GEM method,and the dynamics of a plate structure with an attached dynamic absorber is modeled by the local attached impedance method.The establishment of the theoretical model deepens the understanding of the 1D ABH-DVA damping mechanism and provides a reference value and necessary theoretical basis for the subsequent design and research work of 1D ABH-DVA.The basic 1D ABH-DVA is designed based on the symmetric 1D acoustic black hole beam,and four improved design solutions are proposed on this basis.The GEM dynamics modeling of the 1D ABH-DVA with the five design schemes is carried out,and its energy aggregation characteristics,impedance characteristics,modal and damping characteristics are studied and analyzed.The vibration peak suppression effect of 1D ABH-DVA on the plate structure was verified by using a four-sided simply supported thin plate as the main structure,and the damping characteristics of 1D ABH-DVA were analyzed from both acoustic black hole and dynamic absorber perspectives.The verification of the robustness of 1D ABH-DVA on the vibration control of the plate structure is completed,and the verification results show that 1D ABH-DVA shows good damping effect in the face of various working conditions.The vibration control effects of five 1D ABH-DVA design solutions on the plate structure are compared,and the damping mechanism of 1D ABH-DVA is analyzed by combining the energy aggregation characteristics,impedance characteristics,modal and damping characteristics of 1D ABH-DVA itself.In order to obtain the vibration suppression effect in a wide frequency range,the array distribution design of 1D ABH-DVA is carried out in this thesis,and its vibration suppression effect of wide frequency on the plate structure is verified.Finally,the further application extension of 1D ABH-DVA was completed.1D ABH-DVA arrays were arranged in the base ribs and upper and lower panels,and the additional mass of 1D ABH-DVA relative to the base was 4.8%,and the average vibration reduction effect in the frequency range of 10Hz～10k Hz reached 2.1d B,which verified the vibration control effect of 1D ABH-DVA on the base structure.