A nondestructive method for estimation of the fracture toughness of CrMoV rotor steels based on ultrasonic nonlinearity

Jeong, Hyunjo; Nahm, Seung Hoon; Jhang, Kyung-Young; Nam, Young-Hyun

doi:10.1016/s0041-624x(03)00154-9

Cited by 38 publications

(18 citation statements)

References 12 publications

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“…33 Also reported in literature are creep assisted microstructure variations in CrMoV rotor steels. 3 CrMoV steel samples were heattreated and fracture appearance transition temperature (FATT) was determined as a function of aging time for calculating fracture toughness. The second harmonic measurements correlated with FATT data.…”

Section: Applications To Other Failure Mechanismsmentioning

confidence: 99%

“…Since material failure or degradation is usually preceded by some kind of non-linear mechanical behavior before significant plastic deformation or material damage occurs, considerable attention has recently been focused on the application of nonlinear ultrasonics. 2,3 Linear acoustics deals with propagation of vibrations through medium. Deviations from the equilibrium state of a medium that are caused by these vibrations are assumed to be small; that is, the propagating wave is assumed to have small amplitude or a low intensity.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nonlinear ultrasonic techniques for nondestructive assessment of micro damage in material: A review

Jhang

2009

Int. J. Precis. Eng. Manuf.

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581

262

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The nondestructive assessment of the damage that occurs in components during service plays a key role for condition monitoring and residual life estimation of in-service components/structures. Ultrasound has been widely utilized for this; however most of these conventional methods using ultrasonic characteristics in the linear elastic region are only sensitive to gross defects but much less sensitive to micro-damage. Recently, the nonlinear ultrasonic technique, which uses nonlinear ultrasonic behavior such as higher-harmonic generation, subharmonic generation, nonlinear resonance, or mixed frequency response, has been studied as a positive method for overcoming this limitation. In this paper, overall progress in this technique is reviewed with the brief introduction of basic principle in the application of each nonlinear ultrasonic phenomenon.

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Section: Applications To Other Failure Mechanismsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nonlinear ultrasonic techniques for nondestructive assessment of micro damage in material: A review

Jhang

2009

Int. J. Precis. Eng. Manuf.

Self Cite

581

262

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“…This effect is known as the contact acoustic nonlinearity (CAN), and it has been the topic of much research work concerning the characterization of closed cracks or imperfect bond interfaces [1]. Earlier theoretical investigations [2][3][4] predicted that a weak or incompletely bonded interface will generate high second harmonics when subjected to sufficiently intense acoustic energy, and previous experiments have indicated that acoustic harmonic generation occurs on various types of interface, such as unbounded interfaces [5] microstructural changes [6][7][8][9], cracks [10][11][12] and adhesive joints [13,14].…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Time Reversal Focusing and Detection of Fatigue Crack

Jeong

Barnard²

2012

Journal of the Korean Society for Nondestructive Testing

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This paper presents an experimental study on the detection and location of nonlinear scattering source due to the presence of fatigue crack in a laboratory specimen. The proposed technique is based on a combination of nonlinear elastic wave spectroscopy(NEWS) and time reversal(TR) focusing approach. In order to focus on the nonlinear scattering position due to the fatigue crack, we employed only one transmitting transducer and one receiving transducer, taking advantage of long duration of reception signal that includes multiple linear scattering such as mode conversion and boundary reflections. NEWS technique was then used as a pre-treatment of TR for spatial focusing of reemitted second harmonic signal. The robustness of this approach was demonstrated on a cracked specimen and the nonlinear TR focusing behavior is observed on the crack interface from which the second harmonic signal was originated.

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“…This effect is known as contact acoustic nonlinearity (CAN), and it has been the topic of many research works concerning the characterization of closed cracks or imperfect bond interfaces [1]. Earlier theoretical investigations [2][3][4] predicted that a weak or incompletely bonded interface will generate high second harmonics when subjected to sufficiently intense acoustic energy, and previous experiments have indicated that acoustic harmonic generation occur on various types of interfaces such as unbounded interfaces [5], microstructural changes [6][7][8][9][10][11], and adhesive joints [12,13].…”

Section: Introductionmentioning

confidence: 99%

Measurements of Nonlinear Harmonic Waves at Cracked Interfaces

Jeong¹,

Barnard²

2011

AIP Conference Proceedings

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Nonlinear harmonic waves generated at cracked interfaces are investigated both experimentally and theoretically. A compact tension specimen is fabricated and the amplitude of transmitted wave is analyzed as a function of position along the fatigued crack surface. In order to measure as many nonlinear harmonic components as possible a broadband Lithium Niobate (LiNbO 3 ) transducers are employed together with a calibration technique for making absolute amplitude measurements with fluid-coupled receiving transducers. Cracked interfaces are shown to generate high acoustic nonlinearities which are manifested as harmonics in the power spectrum of the received signal. The first subharmonic (f∕2) and the second harmonic (2f) waves are found to be dominant nonlinear components for an incident toneburst signal of frequency f. To explain the observed nonlinear behavior a partially closed crack is modeled by planar half interfaces that can account for crack parameters such as crack opening displacement and crack surface conditions. The simulation results show reasonable agreements with the experimental results. ABSTRACT. Nonlinear harmonic waves generated at cracked interfaces are investigated both experimentally and theoretically. A compact tension specimen is fabricated and the amplitude of transmitted wave is analyzed as a function of position along the fatigued crack surface. In order to measure as many nonlinear harmonic components as possible a broadband Lithium Niobate (LiNbO 3 ) transducers are employed together with a calibration technique for making absolute amplitude measurements with fluid-coupled receiving transducers. Cracked interfaces are shown to generate high acoustic nonlinearities which are manifested as harmonics in the power spectrum of the received signal. The first subharmonic (f/2) and the second harmonic (2f) waves are found to be dominant nonlinear components for an incident toneburst signal of frequency f. To explain the observed nonlinear behavior a partially closed crack is modeled by planar half interfaces that can account for crack parameters such as crack opening displacement and crack surface conditions. The simulation results show reasonable agreements with the experimental results.

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A nondestructive method for estimation of the fracture toughness of CrMoV rotor steels based on ultrasonic nonlinearity

Cited by 38 publications

References 12 publications

Nonlinear ultrasonic techniques for nondestructive assessment of micro damage in material: A review

Nonlinear ultrasonic techniques for nondestructive assessment of micro damage in material: A review

Nonlinear Time Reversal Focusing and Detection of Fatigue Crack

Measurements of Nonlinear Harmonic Waves at Cracked Interfaces

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