Research on a laser ultrasound method for testing the quality of a nuclear radiation protection structure

Zhang, Kuanshuang; Zhou, Zhenggan; Ma, Liyin

doi:10.1088/1361-6501/28/2/025204

Cited by 12 publications

(7 citation statements)

References 23 publications

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“…Among the ultrasonic induction methods, the photoacoustic effect obtained by pulsed lasers is undoubtedly the most efficient. Pulses of coherent radiation reach the surface of the component, triggering states of deformation by expansion (heating) and contraction (cooling) which propagate inside the material [22][23][24][25][26]. Although wave induction by pulsed lasers applies to any type of material and involves high ultrasonic amplitudes, the levels of irradiance reached often exceed 1 MW cm −2 ; hence particular care must be taken to avoid localized ablation of the component [27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Crack detection with gas-coupled laser acoustic detection technique

Vangi

Bruzzi

Caron

et al. 2021

Meas. Sci. Technol.

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Gas-coupled laser acoustic detection (GCLAD) is an unestablished ultrasonic detection technique based on the displacement that a laser beam sustains when intersected by an acoustic wave travelling in a fluid. In the present work, GCLAD for the noncontact detection of ultrasound is applied to identify surface defects on metal plates. Two GCLAD configurations are analysed, each associated with different sensitivities to cracks; specifically, GCLAD exhibits the highest sensitivity when inclined perpendicularly to the ultrasonic propagation direction in the air. The high angular selectivity allows evidencing only specific waves, those directly travelling in the component or reflected by defects. A higher ultrasonic amplitude is highlighted for GCLAD compared to air-coupled probes. The work ultimately demonstrates GCLAD's major advantage: the possibility of instantly performing an inspection over an entire line, rather than on a point as for traditional transducers.

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Section: Introductionmentioning

confidence: 99%

Crack detection with gas-coupled laser acoustic detection technique

Vangi

Bruzzi

Caron

et al. 2021

Meas. Sci. Technol.

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“…Fatigue cracks and corrosion are a major cause of failure in plate-like metallic structures [1], and about 90% of the failures of in-service metallic structures are caused by fatigue cracks [2]. Compared with traditional ultrasonic testing technology, laser ultrasonics has the advantages of non-contact, high spatial resolution, wide bandwidth and online inspection [3][4][5][6]. It allows harsh environment [3] (such as high temperature, high pressure, strong radiation and so on), various material (such as metals, composite materials [4], nuclear radiation protective materials [5], polymeric materials [6] and so on) and geometrically complex structure testing [7].…”

Section: Introductionmentioning

confidence: 99%

Surface crack characterization using laser nonlinear ultrasonics based on the bispectrum

Liu¹,

Wang²,

Zheng³

2020

Meas. Sci. Technol.

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Laser nonlinear wave modulation spectroscopy (LNWMS) has been used to detect nonlinear ultrasonic signatures caused by fatigue cracks in materials. The nonlinear feature extraction from the spectral plot plays a significant role in LNWMS. This paper uses the bispectrum to distinguish harmonically related signals which result from nonlinear interactions and to remove those which do not. A feature called bispectrum damage factor (BDF), which is defined as the ratio of the bispectrum peak difference value of the damage and intact signals to the bispectrum peak value of intact signals at frequencies F 1, F 2, is extracted from the bispectral plot to characterize the crack features. The basic premise of the proposed laser nonlinear wave modulation bispectrum (LNWMBS) is that this BDF value will vary regularly as the level of crack-induced nonlinearity increases. A finite element model and a noncontact laser ultrasonic system have been built for LNWMBS measurement. The simulation results show that the BDF value is sensitive to crack depth and angle, and is insensitive to crack length and detecting position. BDF values of reflected Rayleigh waves are positive and approximately linearly increase with an increase of the crack depths in the range of 0.1 λ ∼ 0.6 λ (λ is the corresponding wavelength of adopted frequency); meanwhile, the values of the transmitted waves are negative and decreasing. The BDF values are larger than the crack angle at 90° when they are less than 90°, which is beneficial for crack detection. The proposed LNWMBS technique has been successfully tested for detecting artificial sub-millimeter surface-breaking cracks in aluminum alloy plates and closed fatigue cracks of torque load simulator connection blocks.

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“…Therefore, noise reduction method is necessary. Common signal decomposition algorithms include Wigner-Ville distribution, Fri1, and wavelet transform [31][32][33]. However, there is cross interference with the Wigner-Ville distribution.…”

Section: Introductionmentioning

confidence: 99%

Quantitative Imaging Detection of Additive Manufactured Parts Using Laser Ultrasonic Testing

et al. 2020

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Selective laser melting (SLM) is an important method of additive manufacturing, however it has some disadvantages such as poor surface qualities of the formed parts and the appearances of small surface defects. In this paper, 360L stainless steel with artificial defects in different lengths are processed by SLM processing. A full noncontact laser ultrasonic-based B-scan detection system is built to detect the surface defects. The interaction between the scattered surface wave and the surface defect is verified through 3-dimension (3D) finite element simulation. In order to improve the signal-to-noise ratio (SNR) of laser ultrasonic signal in AM 316L part, Variational Mode Decomposition (VMD) algorithm based particle swarm optimization (PSO) is applied to denoise signals. Meanwhile, wavelet transform (WT) algorithm is used to compare SNR with VMD algorithm. Then, the time and amplitude parameters of different positions are extracted to realize B-scan imaging, and the lengths of defects are further accurately quantified through the time-amplitude-position imaging images. Otherwise, we find that the size of laser spot affects the precise quantification of defects. The smaller the spot is, the more precise the quantitative effect is. The results show that this method can quantitatively detect surface defects of AM 316L parts.

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Research on a laser ultrasound method for testing the quality of a nuclear radiation protection structure

Cited by 12 publications

References 23 publications

Crack detection with gas-coupled laser acoustic detection technique

Crack detection with gas-coupled laser acoustic detection technique

Surface crack characterization using laser nonlinear ultrasonics based on the bispectrum

Quantitative Imaging Detection of Additive Manufactured Parts Using Laser Ultrasonic Testing

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