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A new technique for ultrasonic-nondestructive evaluation of thin specimens

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Abstract

Combining standard FFT methods with conventional ultrasonics, a method has been developed for measuring the phase velocity, the group velocity and the attenuation in ultrathin specimens (submillimeter or subwavelength in thickness). A detailed description of this technique is given. The technique was used on four disparate materials: aluminum, an epoxy, a particulate composite and a graphite-fiber/epoxy composite. The method works equally well for thin or thick specimens, and for dispersive as well as nondispersive media.

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Abbreviations

a :

a characteristic length; half crack length or particle radius, mm

c, c 1 :

longitudinal phase velocity in specimen, mm/μs

c 0 :

longitudinal phase velocity of wave in immersion medium (water), mm/μs

c g :

group velocity in specimen, mm/μs

f :

frequency, MHz

f c :

cut-off frequency, MHz

Δf :

frequency resolution, MHz

F *(ω):

Fourier transform off(t)

G *(ω):

Fourier transform ofg(t)

h :

plate thickness, mm

i :

\(\sqrt { - 1} \)

k :

complex wave number=k 1+ik 2, mm−1

k 0 :

wave number in water, real, mm−1

k 1 :

ω/c, wave number in specimen, mm−1

k 2 :

attenuation coefficient, nepers/mm

m :

integer; number of complete round trips taken by the wave across the plate thickness

M :

magnitude of a complex number

N :

number of digitizing points

R ij :

reflection coefficient in mediumi from mediumj

T :

sampling interval in time domain, ns

T 0 :

signal length, μs

T ij :

transmission coefficient for a wave incident in mediumi and transmitted into mediumj

t :

time, μs

u :

particle displacement

x :

distance

Ω:

normalized frequency, 2πfa/c 1

λ:

wavelength, mm

ζ:

normalized wave number, 2πfa/〈c 1〉

ϱ:

density of specimen, g/ml

288-2 :

density of water, g/ml

ϕ:

phase of a complex number

ω:

circular frequency, rad/μs

〈 〉:

aggregate property of composite

References

  1. Tauchert, T.R. andGuzelsu, A.M., “An Experimental Study of Dispersion of Stress Waves in a Fiber-Reinforced Composite”ASME J. Appl. Mech.,39,98–102 (1972).

    Google Scholar 

  2. Kolsky, H., “Stress Waves in Solids”, Dover (1953).

  3. Chang, F.H., Couchman, J.C. andYee, B.G.W., “Ultrasonic Resonance Measurements of Sound Velocity in Thin Composite Laminates,”J. Comp. Mat.,8,356–363 (Oct. 1974).

    Google Scholar 

  4. Heyman, J.S., “Phase Insensitive Acoustoelectric Transducer,”J. Acoust. Soc. Amer.,64 (1),243–249 (July 1968).

    Google Scholar 

  5. Achenbach, J.D., “Wave Propagation in Elastic Solids,” North-Holland Publishing Company (1973).

  6. Kolsky, H., “The Propagation of Stress Pulses in Viscoelastic Solids,”The Phil. Mag.,8, (1),693 (Aug. 1956).

    Google Scholar 

  7. Brigham, E.O., “The Fourier Transform,” Prentice Hall (1974).

  8. Kinra, V.K., Petraites, M.S. andDatta, S.K., “Ultrasonic Wave Propagation in a Random Particulate Composite,”Int. J. Solids Struct.,16,301–312 (1980).

    Google Scholar 

  9. Kinra, V.K. andAnand, A., “Wave Propagation in a Random Particulate Composite at Long and Short Wavelength,”Int. J. Solids, Struct.,18 (5),367–380 (1982).

    Google Scholar 

  10. Kinra, V.K. andKer, E.L., “Effective Elastic Moduli of a Thin-Walled Glass Microsphere/PMMA Composite,”J. Comp. Mat.,16,117–188 (March 1982).

    Google Scholar 

  11. Wolfenden, A., Harmouche, M.R., Blessing, G.V., Chen, Y.T., Terranora, P., Kinra, V.K., Dayal, V., Lemmens, J.W., Phillips, R., Smith, J.S. and Wann, R.J., “Dynamic Young's Modulus Measurements in Nickel-Based Alloys: Six Methods,” to appear. J. Test. Eval.

  12. Kinra, V.K. andLi, P.N., “Resonant Scattering of Elastic Waves by a Random Distribution of Inclusions,”Int. J. Solids Struct.,22 (1),1–11 (1986).

    Google Scholar 

  13. Kinra, V.K., “Dispersive Wave Propagation in Random Particulate Composites,” Recent Advances in Composites in the United States and Japan, ASTM STP 864, ed. J.R. Vinson and M. Taya, 309–325 (1985).

  14. Kinra, V.K. and Rousseau, C.Q., “Acoustical and Optical Branches of Wave Propagation: Some Additional Results,” Proc. Multiple Scattering of Waves in Random Media and Random Rough Surfaces, The Penn. State Univ., ed. V.K. Vardan and V.V. Vardan, 603–613 (1985).

  15. Hashin, Z. andShtrikman, S., “A Variational Approach to the Theory of The Elastic Behavior of Multiphase Materials,”J. Mech. Phys. Solids,11,127–140 (1963).

    MathSciNet  Google Scholar 

  16. Dayal, V., Eden, J.G. and Kinra, V.K., “Ultrasonic Nondestructive Testing of Matrix Cracks in Fiber-Reinforced Composites,” to be submitted to Experimental Mechanics.

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Authors and Affiliations

  1. Department of Aerospace Engineering, Texas A&M University, 77840, College Station, TX

    V. K. Kinra (Associate Professor)

  2. Department of Mechanical Engineering, North Carolina A&T University, 27411, Greensboro, NC

    V. Dayal (Assistant Professor)

Authors
  1. V. K. Kinra
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  2. V. Dayal
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Kinra, V.K., Dayal, V. A new technique for ultrasonic-nondestructive evaluation of thin specimens. Experimental Mechanics 28, 288–297 (1988). https://doi.org/10.1007/BF02329025

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  • DOI: https://doi.org/10.1007/BF02329025

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