Absolute Stress Determination from Angular Dependence of Ultrasonic Velocities in Orthotropic Materials

Degtyar, A. D.; Rokhlin, S. I.

doi:10.1007/978-1-4615-1987-4_243

Cited by 3 publications

(3 citation statements)

References 14 publications

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“…However, for operation under realistic conditions, near-homogeneous stresses in plate-like structures are in general biaxial with unknown principal directions. Degtyar and Rokhlin [42] developed an analogous approach to simultaneously calculate stresses by inverting the angle dependence of phase velocities as measured with bulk waves.…”

Section: Inversion Of Acoustoelastic Lamb Wave Datamentioning

confidence: 99%

Understanding and Exploiting the Effects of Loading on Ultrasonic Sensing Systems for Structural Health Monitoring

Michaels¹,

Michaels²,

Lee³

et al. 2012

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Section: Inversion Of Acoustoelastic Lamb Wave Datamentioning

confidence: 99%

Understanding and Exploiting the Effects of Loading on Ultrasonic Sensing Systems for Structural Health Monitoring

Michaels¹,

Michaels²,

Lee³

et al. 2012

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“…-(8) suggest a strategy to estimate the principal values and direction of the applied stresses. First, acoustoelastic constants K 1 and K 2 are estimated by least squares from known uniaxial applied loads via Eq.…”

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confidence: 99%

In situ estimation of applied biaxial loads with Lamb waves

Shi

Michaels

Lee

2013

The Journal of the Acoustical Society of America

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Spatially distributed arrays of piezoelectric disks are being applied to monitor structural integrity using Lamb waves. Applied loads directly affect waves propagating between array elements because of dimensional changes and the acoustoelastic effect. Resulting changes in phase velocity depend upon the propagation direction as well as the Lamb wave mode and frequency. This paper shows from numerical solutions of the acoustoelastic wave equation for an isotropic plate that it is possible to decouple the effects of a homogeneous biaxial stress into its two principal components. As a consequence of both this decoupling and material isotropy, the acoustoelastic response of a specific mode and frequency is described by only two constants, which can be determined from a uniaxial loading experiment. Using this formulation, a method is developed and verified via simulations to estimate an arbitrary biaxial load from phase velocity changes measured along multiple directions of propagation. Results from uniaxial loading experiments on two different plates further demonstrate the efficacy of the method. It is also shown that opening fatigue cracks may significantly degrade results by interfering with Lamb wave direct arrivals, but that this degradation can be mitigated by using a reduced set of data from unaffected paths of propagation.

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“…Pao et al [3,4] provided a detailed summary of acoustoelastic theory of bulk waves, and derived several formulae to calculate residual stresses, including acoustoelastic birefringence techniques. Degtyar and Rokhlin [5] also developed an approach to simultaneously calculate stresses and stress-dependent elastic constants by inverting the angle dependence of phase velocities as measured with bulk waves.…”

Section: Introductionmentioning

confidence: 99%

In Situ Estimation of Applied Biaxial Loads with Lamb Waves (Preprint)

Shi¹,

Michaels²,

Lee³

2012

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The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information SPONSORING/MONITORING AGENCY REPORT NUMBER(S) AFRL-RX-WP-TP-2012-0353 DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution unlimited. Preprint to be submitted to Journal of the Acoustical Society of America. SUPPLEMENTARY NOTESThis work was funded in whole or in part by Department of Air Force contract FA8650-09-C-5206. The U.S. Government has for itself and others acting on its behalf an unlimited, paid-up, nonexclusive, irrevocable worldwide license to use, modify, reproduce, release, perform, display, or disclose the work by or on behalf of the U.S. Government. PA Case Number and clearance date: 88ABW-2012-0773, 14 February 2012. This document contains ABSTRACTSpatially distributed arrays of piezoelectric discs are being applied to monitor the integrity of critical metallic structures using guided elastic waves. These transducers are subjected to in situ operational and environmental conditions, and stress variations are of particular importance because of their cumulative effects on the fatigue life of the structures. Waves propagating between array elements are directly affected by applied loads because of both dimensional changes and the acoustoelastic effect. In particular, changes in phase velocity are a function of the direction of propagation for a particular Lamb wave mode and frequency. This paper shows from numerical solutions of the acoustoelastic wave equation that it is possible to decouple the effects of a homogeneous biaxial stress into its two principal components. As a consequence of this decoupling combined with material isotropy, the acoustoelastic response of guided waves is described by only two constants, both of which can be determined from a single uniaxial loading experiment. ABSTRACT. Spatially distributed arrays of piezoelectric discs are being applied to monitor the integrity of critical metallic structures using guided elastic waves. These transducers are subjected to in situ operational and environmental conditions, and stress variations are of particular importance because of their cumulative effects on the fatigue life of the structures.Waves propagating between array elements are directly affected by applied loads because of both dimensional changes and the acoustoelastic effect. In particular, changes in phase velocity are a function of the direction of propagation for a particular Lamb wave mode and frequency. This paper shows from numerical solutions of the acoustoelastic wave equation that it is po...

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Absolute Stress Determination from Angular Dependence of Ultrasonic Velocities in Orthotropic Materials

Cited by 3 publications

References 14 publications

Understanding and Exploiting the Effects of Loading on Ultrasonic Sensing Systems for Structural Health Monitoring

Understanding and Exploiting the Effects of Loading on Ultrasonic Sensing Systems for Structural Health Monitoring

In situ estimation of applied biaxial loads with Lamb waves

In Situ Estimation of Applied Biaxial Loads with Lamb Waves (Preprint)

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