Simulation Study on the Blocking Effect and Vibration Reduction Characteristics of Acoustic Black Hole in Thin Plate

Z Liu,A Golyanin,Y Zhou

doi:10.33619/2414-2948/53/26

Abstract

Recently, more and more scholars have devoted themselves to researching new methods of vibration reduction and noise reduction by manipulating the elastic waves in the structure to achieve the purpose of vibration reduction and noise reduction. To this end, a new type of ‘acoustic black hole’ structure is proposed, which reduces structural vibration while avoiding problems such as mass increase. In this paper, the vibration damping performance of the structure is mainly calculated by finite element software, and the energy concentration effect of the thin plate containing the acoustic black hole is verified by finite element analysis. A thin plate structure with four acoustic black holes is proposed. The calculation shows that the structure has obvious vibration reduction effect, and the vibration reduction effect can reach more than 20dB at high frequency.

Highlights

Ключевые слова: акустическая черная дыра, тонкая пластина, демпфирование колебаний, временная область, частотная область, поток механической энергии
In 2001, the zero-reflection effect of sound waves in thin plates with variable thickness was used as an effective absorber of bending vibration [4], in 2004 the physical effect was named "acoustic black hole" [5]
Theoretical research shows that an ideal acoustic black hole structure can perfectly capture waves using its zero-reflection effect to form a trap, but it is limited by processing and manufacturing processes

Summary

Finite element simulation

A thin plate with a single ideal acoustic black hole is taken as the research object. A rectangular thin plate with a length of 60 cm, a width of 40 cm, and a thickness of 0.5 cm is established. Create a perfect acoustic black hole with a radius of 9cm and a thickness satisfying the power law y 50 / 81x2 in the center of the plate. A force of F 100sin(10000t) on the right side.

MATERIAL PARAMETERS OF THE THIN PLATE

Acoustic black hole grid model

Findings

Conclusion