The acoustic wave generation in a specimen irradiated by a pulsed microwave is predicted theoretically. The specimen is a viscoelastic rod inserted into a wave guide. The model is based on Maxwell’s equations, heat equation and thermoviscoelasticity theory. Computations show the presence of temperature oscillations due to the electromagnetic interferences in the irradiated rod if its electromagnetic absorption is low. An experimental method to infer indirectly the detailed behavior of microwave-generated acoustic waves in polymer rods, including the influence of electromagnetic wave reflection at the rod ends, is presented. The method consists of measuring the oscillations in the particle acceleration detected at the end of the rod that are induced by variations in the polymer rod length. The oscillations are caused by changing electromagnetic standing-wave conditions within the rod. It is found that these oscillations are in agreement in period, amplitude, and phase, with independent values of the complex dielectric constant and complex acoustic slowness of the polyvinyl chloride samples used in the study.

1.
D. A. Hutchins, Ultrasonic Generation by Pulsed Laser, edited by W. P. Mason and R. N. Thurston (Physical Acoustics, New York, 1988), Vol. XVII.
2.
C. K.
Chou
and
A. W.
Guy
, “
Auditory perception of radio-frequency electromagnetic fields
,”
J. Acoust. Soc. Am.
71
,
1321
1334
(
1982
).
3.
B.
Abeles
,
Phys. Rev. Lett.
19
,
1181
(
1967
).
4.
A.
Zemel
and
Y.
Goldstein
, “
Conversion of electromagnetic into acoustic energy via indium films
,”
Phys. Rev. B
7
,
191
200
(
1973
).
5.
A.
Zemel
and
Y.
Goldstein
, “
Conversion of electromagnetic into acoustic energy using Sn, Au and Cu films at a low temperatures
,”
Phys. Rev. B
9
,
1499
1505
(
1974
).
6.
Y.
Goldstein
,
S.
Barzilai
, and
A.
Zemel
, “
Electron mean-free-path dependence of electromagnetic phonon generation
,”
Phys. Rev. Lett.
32
,
463
466
(
1974
).
7.
D. E.
Chimenti
, “
Nonlocal electromagnetic acoustic wave generation in aluminum films
,”
Phys. Rev. B
13
,
4245
4251
(
1976
).
8.
J. E. Michaels, “Thermally induced elastic wave propagation in slender bars,” Proceedings of the 3rd U.S. National Congress on Applied Mechanics (American Society of Mechanical Engineers, New York, 1958), p. 209.
9.
R. M.
White
, “
Generation of elastic waves by transient surface heating
,”
J. Appl. Phys.
34
,
3559
3567
(
1963
).
10.
L. S.
Gournay
, “
Conversion of electromagnetic to acoustic energy by surface heating
,”
J. Acoust. Soc. Am.
40
,
1322
1330
(
1966
).
11.
D. E.
Borth
and
C. A.
Cain
, “
Theoretical analysis of acoustic signal generation in materials irradiated with microwave energy
,”
IEEE Trans. Microwave Theory Tech.
MTT-25
,
944
953
(
1977
).
12.
L. M.
Lyamshev
and
B. I.
Chelnokov
, “
Sound generation in a solid by penetrating radiation
,”
Sov. Phys. Acoust.
29
,
220
225
(
1983
).
13.
F.
Enguehard
and
L.
Bertrand
, “
Effects of optical penetration and laser pulse duration on laser generated longitudinal acoustic waves
,”
J. Appl. Phys.
82
,
1532
1538
(
1997
).
14.
B.
Hosten
and
P. A.
Bernard
, “
Ultrasonic wave generation by time-gated microwaves
,”
J. Acoust. Soc. Am.
104
,
860
866
(
1998
).
15.
C.
Bacon
,
B.
Hosten
, and
P. A.
Bernard
, “
Acoustic wave generation in viscoelastic rods by time-gated microwaves
,”
J. Acoust. Soc. Am.
106
,
195
201
(
1999
).
16.
E. Guilliorit, C. Bacon, and B. Hosten, “Génération d’ondes acoustiques par micro-ondes impulsionnelles,” 14èmeCongrès Français de Mécanique, No. 91 in CD-Rom, Toulouse, France, 1999.
17.
B. Hosten and C. Bacon, “Measurement of complex young moduli of composite materials by time-gated microwaves,” in Review of Progress in Quantitative Non Destructive Evaluation, edited by D. O. Thompson and D. E. Chimenti (Plenum, New York, 2000), Vol. 19, pp. 1113–1120.
18.
R. M. Cristensen, Theory of Viscoelasticity: An Introduction (Academic, New York, 1971).
19.
C.
Bacon
, “
An experimental method for considering dispersion and attenuation in a viscoelastic Hopkinson bar
,”
Exp. Mech.
38
,
242
249
(
1998
).
20.
M. N.
Islam
,
C.
Edwards
, and
S. B.
Palmer
, “
Detection of laser generated Lamb waves in non-metals by capacitance transducers
,”
Nondestr. Test. Eval.
11
,
9
20
(
1994
).
21.
D.
Hutchins
and
J. D.
Macphail
, “
A new design of capacitance transducer for ultrasonic displacement detection
,”
J. Phys. E
18
,
69
72
(
1985
).
This content is only available via PDF.
You do not currently have access to this content.