Sound radiation from rectangular baffled and unbaffled plates

The radiation efficiency of a flat rectangular plate is often used as a basis on which to represent the sound radiation from more complex plate-like structures. The solution for a plate set in a rigid baffle is well known, including the radiation efficiency for multi-modal response of the plate. In this case the assumption is usually made that each mode within a given frequency band has equal modal vibration energy. This paper explores a number of limitations of this simple result. First, the extent to which the radiation efficiency for a particular forcing point deviates from the modal-average result is investigated. Second, the difference is shown between the results for a baffled plate and an unbaffled plate. For a multi-modal response, an empirical formula is also presented which allows the radiation efficiency to be estimated for the unbaffled case. Finally, the effect of different boundary conditions on both baffled and unbaffled results is demonstrated by comparing the results for guided boundaries with those for simply supported boundaries.

[1]  H. Nelisse,et al.  A GENERALIZED APPROACH FOR THE ACOUSTIC RADIATION FROM A BAFFLED OR UNBAFFLED PLATE WITH ARBITRARY BOUNDARY CONDITIONS, IMMERSED IN A LIGHT OR HEAVY FLUID , 1998 .

[2]  B. Laulagnet,et al.  Sound radiation by a simply supported unbaffled plate , 1998 .

[3]  S. Snyder,et al.  Calculating total acoustic power output using modal radiation efficiencies , 1995 .

[4]  Edward Granville Broadbent,et al.  Acoustic radiation from rectangular panels with constrained edges , 1984, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[5]  C. Wallace.  Radiation Resistance of a Rectangular Panel , 1972 .

[6]  W. L. Li,et al.  DETERMINATION OF THE MUTUAL RADIATION RESISTANCES OF A RECTANGULAR PLATE AND THEIR IMPACT ON THE RADIATED SOUND POWER , 2000 .

[7]  K. H. Heron,et al.  The acoustic radiation efficiency of rectangular panels , 1982, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[8]  Allan D. Pierce,et al.  Acoustics , 1989 .

[9]  Steven Dubowsky,et al.  A RADIATION EFFICIENCY FOR UNBAFFLED PLATES WITH EXPERIMENTAL VALIDATION , 1997 .

[10]  E. G. Willams.  A series expansion of the acoustic power radiated from planar sources , 1983 .

[11]  E. E. Ungar,et al.  Structure-borne sound , 1974 .

[12]  Alain Berry,et al.  A general formulation for the sound radiation from rectangular, baffled plates with arbitrary boundary conditions , 1990 .

[13]  Chris Jones,et al.  The radiation efficiency of baffled plates and strips , 2005 .

[14]  István L. Vér.  Interaction of Sound Waves with Solid Structures , 2007 .

[15]  Julian D. Maynard,et al.  Numerical evaluation of the Rayleigh integral for planar radiators using the FFT , 1982 .

[16]  Earl G. Williams,et al.  Numerical evaluation of the radiation from unbaffled, finite plates using the FFT , 1983 .

[17]  G. Maidanik,et al.  Radiation Efficiency of Panels , 1963 .

[18]  L. Rayleigh,et al.  The theory of sound , 1894 .

[19]  David Thompson,et al.  Sound radiation from perforated plates , 2010 .

[20]  W. L. Li.  Vibroacoustic analysis of rectangular plates with elastic rotational edge restraints , 2006 .

[21]  Frank Fahy,et al.  Sound and Structural VibrationRadiation, Transmission and Response , 2007 .

[22]  Noureddine Atalla,et al.  Acoustic radiation of an unbaffled vibrating plate with general elastic boundary conditions , 1996 .

[23]  John L. Davy.  The forced radiation efficiency of finite size flat panels that are excited by incident sound. , 2009, The Journal of the Acoustical Society of America.

[24]  G. Maidanik,et al.  Response of Ribbed Panels to Reverberant Acoustic Fields , 1962 .