关键词: 静压, 吸声覆盖层, 空腔变形, 预应力, 吸声性能

Abstract: An analytical method for the sound absorption performance of the acoustic coating with cavities has been proposed to investigate the effect of the hydrostatic pressure on the performance of the acoustic coating with the consideration of the deformation and prestress of the cavities. By using the finite element method, the sound absorption performance of the acoustic coating that only considers the deformation of the cavities is compared with that of the acoustic coating that considers the deformation and prestress of the cavities under the same hydrostatic pressure. The differences of the maximum deformation, average absorption coefficient and absorption coefficient variation are then studied for the acoustic coating with cylinder, conical and horn cavities under the same porosity and different hydrostatic pressure. The results show that there are significant differences between the sound absorption performance of the acoustic coating that only considers the deformation of the cavities and that of the acoustic coating that considers the deformation and prestress of the cavities. The hydrostatic pressure causes the largest deformation of the coating with cylinder cavities, followed by the coating with horn cavities, and then the coating with conical cavities. The effect of the hydrostatic pressure on the acoustic coating can be neglected below 2000 Hz. The absorption coefficient curves of the acoustic coating with cylinder cavities and conical cavities gradually get closer with the increase of the hydrostatic pressure, and almost match to each other under 10 MPa hydrostatic pressure.

Key words: hydrostatic pressure, acoustic coating, cavity deformation, prestress, absorbing performance