Prediction of Structure-Borne Sound in Orthotropic Plates for Far-Field Conditions

Abstract

Structural intensity method is used to formulate vibration power flow model in naturally orthotropic plates in the frequency domain for far-field conditions considering bending waves. Dimensionless parameters are used in classical orthotropic plate equations to get this power. Techniques of Fourier transform and finite difference approximation are used in the formulation. Shear force components of vibration power transmission in x-direction and y-direction are obtained separately. Total power is obtained from the idea of far-field conditions. Cross-spectral density functions of field signal are used to facilitate the estimation of power transmission. Structural intensity is formulated, which is similar to that of the conventional two-transducer method. A transducer array of two points is required to get an intensity vector in one direction of a point in the plates. A new bending wave number and a modified Laplace operator are also proposed.

Keywords

Vibration intensity bending wave power orthotropy far-field conditions

Get full access to this article

View all access options for this article.

References

Abd. Rahman, R., 1996, A Study of Vibration Power Flow in Fiber-Reinforced Plastic Materials, Ph.D. thesis, University of Technology Malaysia, Malaysia.

Arruda, J.R.F. and Campos, J. P. , 1996, “Experimental determination of flexural power flow in beams using a modified prony method,” Journal of Sound and Vibration 197(3), 309-328.

Bauman, P. D. , 1994, “Analytical and experimental evaluation of various techniques for the case of flexural waves in one-dimensional structures,” Journal of Sound and Vibration 174(5), 677-694.

Bendat, J. S. and Piersol, A. G. , 1986, Random Data: Analysis and Measurement Procedure, John Wiley, New York.

Bosmans, I. Mees, P. , and Vermeir, G. , 1996, “Structure-borne sound transmission between thin orthotropic plates: Analytical solutions,” Journal of Sound and Vibration 191(1), 75-90.

Chow, S. T. , Liew, K. M. , and Lam, K. Y. , 1992, “Transverse vibration of symmetrically laminated rectangular composite plates,” Composite Structures 20, 213-226.

Cremer, L. and Heckl, M. , 1988, Structure-Borne Sound: Structural Vibration and Sound Radiation at Audio Frequencies, Springer-Verlag, Berlin.

Gavric, L. and Pavic G. , 1993, “A finite element method for computation of structural intensity by the normal mode approach,” Journal of Sound and Vibration 164(1), 29-43.

Gorman, D. J. , 1990, “Accurate free vibration analysis of clamped orthotropic plates by the method of superposition,” Journal of Sound and Vibration 140(3), 391-411.

10.

Hambric, S. A. and Taylor, P. D. , 1994, “Comparison of experimental and finite element structure-borne flexural power measurements for a straight beams,” Journal of Sound and Vibration 170, 595-605.

11.

Kuttler, J. R. and Sigillito, V. G. , 1980, “Upper and lower bounds for the frequency of clamped orthotropic plates,” Journal of Sound and Vibration 73(2), 247-259.

12.

Lam, K. Y. , Liew, K. M. , and Chow, S. T. , 1989, “Two-dimensional orthogonal polynomials for vibration of rectangular composite plates,” Composite Structures 13, 239-250.

13.

Liew, K. M. , 1994, “Vibration of clamped circular symmetric laminates,” ASME Journal of Vibration and Acoustics 116, 141-145.

14.

Liew, K. M. , Lam, K. Y. , and Chow, S. T. , 1989, “Study on flexural vibration of triangular composite plates influenced by fibre orientation,” Composite Structures 13, 123-132.

15.

Linjama, J. and Lahti, T. , 1992, “Estimation of bending wave intensity in beams using the frequency response technique,” Journal of Sound and Vibration 153(1), 21-36.

16.

Mandal, N. K., 1998, The Study of Structure-Borne Vibration Power Flow in Orthotropic Plates by the Method of Structural Intensity, Ph.D thesis, University of Technology Malaysia, Malaysia.

17.

Noiseus, D. U. , 1970, “Measurement of power flow in uniform beams and plates,” Journal of Acoustical Society of America 47, 238-247.

18.

Pavic, G. , 1976, “Measurement of structure borne wave intensity, part I: Formulation of the methods,” Journal of Sound and Vibration 49(2), 221-230.

19.

Quinlin, D. , 1985, “Application of the four-channel technique to the measurement of power flow in structures,” in Proceedings of the Second International Congress on Acoustic Intensity, CETIM, Senlis, France, pp. 227-234.

20.

Troitskey, M. S. , 1976, Stiffened Plates: Bending, Stability and Vibration, Elsevier, Amsterdam.

21.

Ugural, A. C. , 1981, Stresses in Plates and Shells, McGraw-Hill, New York.

22.

Verheij, J. W. , 1980, “Cross-spectral density methods for measuring structure borne power flow on beams and pipes,” Journal of Sound and Vibration 70(1), 133-138.