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Speed of Sound in Solids

The situation with solids is considerably more complicated, with different speeds in different directions, in different kinds of geometries, and differences between transverse and longitudinal waves. Nevertheless, the speed of sound in solids is larger than in liquids and definitely larger than in gases.

Young's Modulus for a representative value for the bulk modulus for steel is 160 $ 10^9$ N /$ m^2$ .

Table 3.3: Solids speed of sound, after Aldred, John, Manual of Sound Recording, London:Fountain Press, 1972
material reference Value [m/sec]
Diamond   12000
Pyrex glass   5640
Steel longitudinal wave 5790
Steel transverse shear 3100
Steel longitudinal wave (extensional wave) 5000
Iron   5130
Aluminum   5100
Brass   4700
Copper   3560
Gold   3240
Lucite   2680
Lead   1322
Rubber   1600


Speed of sound in solid of steel, using a general tabulated value for the bulk modulus, gives a sound speed for structural steel of

$\displaystyle c = \sqrt{ E \over \rho} = \sqrt{160 \times 10^{9} N/m^{2} \over 7860 Kg /m^3} = 4512 m/s$ (3.38)

Compared to one tabulated value the example values for stainless steel lays between the speed for longitudinal and transverse waves.


next up previous index
Next: Sound Speed in Two Up: Speed of Sound Previous: Speed of Sound in   Index
genick 2007-11-21