Ultrasound-stimulated vibro-acoustic spectrography is a recently-developed method that employs the radiation force of two intersecting continuous ultrasound beams to remotely vibrate an object at an arbitrary low frequency. Object vibration produces a sound field (acoustic emission) in the medium, which is a function of object mechanical properties. By measuring the acoustic emission field, one can obtain information about the mechanical parameters of the object. In this paper, we use this method for remote (noncontact) measurement of the dynamic Young's modulus of a rod based on its fundamental resonance frequency. Experimental results on an aluminum rod agree with the published data.
SchindelD.W.HutchinsD.A.SmithS.T., A study of materials at high temperature using miniaturized resonant tuning forks and noncontact capacitance transducers, J. Acoust. Soc. Am.102, 1296–1309 (1997).
4.
GarrettS.L., Resonant acoustic determination of elastic moduli, J. Acoust. Soc. Am.88, 210–221 (1990).
TorrG.R., The acoustic radiation force, Am. J. Physics, 52, 402–408 (1984).
7.
WesterveltP.J., The theory of steady force caused by sound waves, J. Acoust. Soc. Am., 23, 312–315 (1951).
8.
MorseP.M.Vibration and Sound, 3rd ed. (The Acoustical Society of America, USA, 1981).
9.
BelvinsR.D., Formulas for Natural Frequency and Mode Shape (Van Nostrand Reinhold, New York, 1979).
10.
FatemiM.GreenleafJ.F., Vibro-acoustography: an imaging modality based on ultrasound-stimulated acoustic emission, Proc. Natl. Acad. Sci.96, 6603–6608 (1999).
11.
MorseP.M.IngardK.U., Theoretical Acoustics (McGraw-Hill, New York, 1968).
12.
FletcherN.H.RossingT.D., Physics of Musical Instruments (Springer-Verlag, New York, 1991).
13.
RossingT.D.RussellD.A.BrownD.E., On the acoustic of tuning forks, Am. J. Phys.60, 620–626 (1992).
