Determination of the Elastic Constants of Composites Through the Inversion of Leaky Lamb Wave Data

Karim, Md. Rezaul; Mal, Ajit; Bar‐Cohen, Yoseph

doi:10.1007/978-1-4684-5772-8_12

Cited by 18 publications

(9 citation statements)

References 4 publications

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“…A different approach to the inverse problem employs the minimization of the dispersion function, as in the study by Karim, Mal, and Bar-Cohen [20]. For an isotropic material, the dispersion function may be written as, where IIZ specifies either symmetric or antisymmetric modes.…”

Section: Inverse Problemmentioning

confidence: 99%

“…Rokhlin and Chimenti [IS, 191 employed a nonlinear least squares inversion scheme to determine the elastic constants for an orthotropic composite plate from leaky Lamb wave phase velocity measurements. Karim, Mal, and Bar-Cohen [20] employed a different type of inversion scheme to determine the elastic constants of a transversely isotropic composite material also using the leaky Lamb wave technique.…”

Section: Introductionmentioning

confidence: 99%

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Elastic Property Measurement Using Rayleigh-Lamb Waves

Rogers

1995

Research in Nondestructive Evaluation

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A nondestructive technique is described for the measurement of elastic constants of isotropic plates using ultrasonic Rayleigh-Lamb waves. The experimental method employs continuous harmonic waves and a pair of variable-angle contact transducers in pitch-catch mode. The phase velocity of the R-L waves at a particular frequency is determined from the phase shift over a measured path length. This simple experimental technique can measure phase velocity over the range 1-10 m m / p with an error of less than 0.5% over a frequency range of 50 kHz-2 MHz. Individual symmetric and antisymmetric modes can be generated through the selection of transducer angle and frequency. Young's modulus and Poisson's ratio for the material are calculated from measurements of frequency and phase velocity by a nonlinear least squares solution to the dispersion equations. The sensitivity of the nonlinear least squares function to the measurement region of the dispersion curve is investigated. It was found that estimations of material properties are more accurate and less sensitive to small experimental errors when only selected frequencies and R-L modes are used in the least squares calculation. This technique is demonstrated with several isotropic materials and with both thick (6 mm) and thin (0.8 mm) plates. Values for elastic constants determined by the contact transducer Lamb wave technique compare favorably with values measured using the pulse-echo-overlap method. The uncertainty in measurements of Young's modulus and Poisson's ratio was less than 1% and 2%, respectively. The technique has advantages over more traditional methods for measuring elastic properties when it is desirable to use wavelengths greater than the plate thickness, when properties may vary with frequency, or when it is necessary to measure in-plane elastic properties of thin plate structures.

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Section: Inverse Problemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Elastic Property Measurement Using Rayleigh-Lamb Waves

Rogers

1995

Research in Nondestructive Evaluation

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“…Several researchers [4,5] are currently investigating the use of a non-linear curve fitting algorithms to determine the elastic constants of thin anisotropic substrates. One such algorithm, known as the SIMPLEX algorithm [10], seems to be a very efficient and accurate method for obtaining the constants.…”

Section: Future Possibilitiesmentioning

confidence: 99%

48416 One sided inspection for elastic constant determination of advanced materials

1994

NDT & E International

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“…In the reconstruction algorithm we used analytical expressions for reflection coefficients from arbitrary oriented orthotropic plate received recently in paper [9]. A different approximate inversion scheme for reflectivity data has been recently used in paper [10] and reconstruction of elastic constants from ultrasonic transmission data has recently been utilized in paper [11].…”

mentioning

confidence: 99%