Experiment and simulation analysis on noise reduction of cylindrical shells with viscoelastic material

Abstract

In order to solve the problem of mid-low frequency noise reduction in cylindrical shells, the experimental and simulation methods are used to study the noise reduction performance of cylindrical shells with different acoustic covering layers in the mid-low frequency range. Firstly, a cylindrical shell noise reduction experimental device was established, the experiment for cylindrical shell structure and laying a viscoelastic material shell structure were carried out. Acoustic commercial software (LMS Virtual. Lab) was used to establish a finite element model for simulation analysis, the numerical results then compared with the experimental results. Finally, the finite element simulation was applied to study the noise response in the cylindrical cavity of lining different materials and the influence of the laying scheme and thickness of the layer. The results show that, in the case of the same laying rate, the oblique laying has a better noise reduction effect and the amount of noise reduction increases as the laying thickness increases. Under a constant thickness of the foam-butyl rubber, as the proportion of butyl rubber increases, the noise reduction per unit thickness increases, while the noise reduction per unit mass decreases. Keywords: Cylindrical shell, Noise reduction, Viscoelastic material, Multi-layer