Production of structural and acoustic waves by dipole sources adjacent to an elastic plate with a pressure‐release coating

1992 ◽  
Vol 91 (3) ◽  
pp. 1310-1319 ◽  
Author(s):  
M. S. Howe
Keyword(s):  
Elastic Plate ◽  
Acoustic Waves ◽  
Pressure Release ◽  
Dipole Sources

Acoustic scattering by a finite nonlinear elastic plate. I Primary, secondary and combination resonances

1987 ◽  
Vol 414 (1846) ◽  
pp. 237-253 ◽  
Keyword(s):  
Incident Wave ◽  
Elastic Plate ◽  
Scattered Field ◽  
Acoustic Waves ◽  
Multiple Scales ◽  
Acoustic Scattering ◽  
Scattered Wave ◽  
Thin Elastic Plate ◽  
Finite Width ◽  
Wave Angle

A thin elastic plate of finite width is irradiated by time-harmonic acoustic waves. The fluid is assumed light compared with the plate mass, and the forcing term is of sufficient amplitude to necessitate the inclusion of a nonlinear term (due to mid-plane stretching) in the plate equation. The order-one scattered field is determined by the method of multiple scales when the forcing frequency approaches a free oscillation frequency (eigenfrequency) of the plate. This solution is shown to agree with previous work, for the linear problem, and can be multivalued for particular values of the plate-fluid parameters. The scattered wave may also exhibit jumps in its amplitude and phase angle as it varies with frequency, incident-wave angle or incident-wave amplitude. The non-linear term further allows the possibility of secondary and combination resonances. These are investigated and the scattered field is shown to contain terms of different frequencies to those of the incident waves. Multivalued solutions and the associated jump phenomenon are again found for these resonant cases.

Resonance theory of acoustic waves interacting with an elastic plate

1979 ◽  
Vol 66 (6) ◽  
pp. 1857-1866 ◽  
Author(s):  
Ralph Fiorito ◽  
Walter Madigosky ◽  
Herbert Überall
Keyword(s):  
Elastic Plate ◽  
Acoustic Waves ◽  
Resonance Theory

The damping of flexural and acoustic waves by a bias-flow perforated elastic plate

1995 ◽  
Vol 6 (4) ◽  
pp. 307-328 ◽  
Author(s):  
M. S. Howe
Keyword(s):  
Wave Equation ◽  
Elastic Plate ◽  
Acoustic Waves ◽  
Homogeneous Distribution ◽  
Circular Aperture ◽  
Fluid Loading ◽  
Numerical Predictions ◽  
Bias Flow ◽  
Vorticity Production ◽  
Bending Wave

An analysis is made of the damping of sound and structural vibrations by vorticity production in the apertures of a bias flow, perforated elastic plate. Unsteady motion causes vorticity to be generated at the aperture edges; the vorticity and its energy are swept away by the bias flow and result in a net loss of acoustic and vibrational energy. In this paper we investigate the interaction of an arbitrary fluid-structure disturbance with a small circular aperture in the presence of a high Reynolds number, low Mach number bias flow. By considering the limit in which the aperture is small compared to the length scale of the impinging disturbance, it is shown that the effect of the interaction can be represented by a concentrated source in the plate bending wave equation consisting of a delta function and two of its axisymmetric derivatives. A generalized bending wave equation is then formulated for a plate perforated with an homogeneous distribution of small, bias flow circular apertures. This equation is used to predict the attenuation of sound and resonant bending waves by vorticity production. Acoustic damping is found to be significant provided the fluid loading is sufficiently small for the plate to be regarded as rigid (e.g. for an aluminium plate in air when the frequency is not too small). On the other hand, a bending wave is effectively damped only when the fluid loading is large enough for the wave to produce a substantial pressure drop across the plate; when this occurs the predicted attenuations are comparable with those usually achieved by the application of elastomeric damping materials. Numerical predictions are presented for steel and aluminium plates in air and water.

Resonant transmission of acoustic waves through an elastic plate quasiperiodically corrugated on surfaces

2011 ◽  
Vol 375 (45) ◽  
pp. 4081-4084 ◽  
Author(s):  
Rui Hao ◽  
Chunyin Qiu ◽  
Yanyun Hu ◽  
Kun Tang ◽  
Zhengyou Liu
Keyword(s):  
Elastic Plate ◽  
Acoustic Waves ◽  
Resonant Transmission
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