The Effects of Stress on Second Harmonics in Plate-Like Structures

Cumulative second harmonic of ultrasonic guided waves is considered to have great application potential in evaluating internal stress of structures. One difficulty with the application is the diversity and complexity of modal response to the stress change in waveguide. At present, there is a lack of relevant theoretical studies and experimental results to guide the applications. In this article, a method is proposed to characterize the amplitude change of cumulative second harmonic mode in a plate under stress through calculating the amplitude coefficient, which can be acquired based on mode shape analysis. The steel plate is taken as an example to demonstrate the analysis method. Experimental studies are presented with results consistent with the theoretical predictions. The results of this study indicate that the amplitudes of different cumulative second harmonic modes may increase or decrease monotonically with the change of stress. Therefore, when the phenomenon of modes mixing occurs in the waveguide, it is necessary to analyze and predict the amplitude of selected cumulative second harmonic mode with the change of stress in advance; otherwise, wrong results may be obtained. The method and conclusions proposed in this paper can also be applicable to waveguide of arbitrary cross-section and have universality.

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Water Level Sensing in a Steel Vessel Using A0 and Quasi-Scholte Waves

Journal of Sensors ◽

10.1155/2017/2596291 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Peng Guo ◽

Bo Deng ◽

Xiang Lan ◽

Kaili Zhang ◽

Hongyuan Li ◽

...

Keyword(s):

Water Level ◽

Guided Waves ◽

Mode Conversion ◽

Experimental Studies ◽

Low Frequency ◽

Steel Vessel ◽

Theoretical Predictions ◽

Travelling Time ◽

The Comparative Study ◽

Group Velocities

This paper presents a water level sensing method using guided waves of A0 and quasi-Scholte modes. Theoretical, numerical, and experimental studies are performed to investigate the properties of both the A0 and quasi-Scholte modes. The comparative study of dispersion curves reveals that the plate with one side in water supports a quasi-Scholte mode besides Lamb modes. In addition, group velocities of A0 and quasi-Scholte modes are different. It is also found that the low-frequency A0 mode propagating in a free plate can convert to the quasi-Scholte mode when the plate has one side in water. Based on the velocity difference and mode conversion, a water level sensing method is developed. For the proof of concept, a laboratory experiment using a pitch-catch configuration with two piezoelectric transducers is designed for sensing water level in a steel vessel. The experimental results show that the travelling time between the two transducers linearly increases with the increase of water level and agree well with the theoretical predictions.

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Excitation and Propagation of Longitudinal L (0, 2) Mode Ultrasonic Guided Waves for the Detection of Damages in Hexagonal Pipes: Numerical and Experimental Studies

Shock and Vibration ◽

10.1155/2021/6641828 ◽

2021 ◽

Vol 2021 ◽

pp. 1-18

Author(s):

Xiang Wan ◽

Meiru Liu ◽

Xuhui Zhang ◽

Hongwei Fan ◽

Qinghua Mao ◽

...

Keyword(s):

Guided Waves ◽

Experimental Studies ◽

Special Kind ◽

Dispersion Curves ◽

Guided Wave ◽

Ultrasonic Guided Waves ◽

Resource Exploitation ◽

Ultrasonic Guided Wave ◽

Study Results ◽

Through Hole

The hexagonal pipe is a special kind of tube structure. Its inner surface of the cross section is in the shape of circle, while the outer surface is hexagonal. It has functioned as an essential and critical part of a drill stem in a high-torque drill machine used in various resource exploitation fields. The inspection of a hexagonal pipe to avoid its failure and thus to ensure safe operation of a drilling machine is becoming increasingly urgent and important. In this study, the excitation and propagation of ultrasonic guided waves for the purpose of detecting defects in hexagonal pipes are proposed. Dispersion curves of hexagonal pipes are firstly derived by using semianalytical ﬁnite element method. Based on these dispersion curves, longitudinal L (0, 2) mode at 100 kHz is selected to inspect hexagonal pipes. A ring of piezoelectric transducers (PZTs) with the size of 25 mm × 5 mm ×0.5 mm is able to maximize the amplitude of L (0, 2) mode and successfully suppress the undesired L (0, 1) mode in the experiments. Numerical and experimental studies have shown that the displacement field of L (0, 2) mode at 100 kHz is almost uniformly distributed along the circumferential direction. Furthermore, L (0, 2) mode ultrasonic guided waves at 100 kHz are capable of detecting circular through-hole damages located in the plane and near the edge in a hexagonal pipe. Our study results have demonstrated that the use of longitudinal L (0, 2) mode ultrasonic guided wave provides a promising and effective alternative for the detection of defects in hexagonal pipe structures.

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THEORETICAL AND EXPERIMENTAL STUDIES OF ULTRASONIC GUIDED WAVES PROPAGATION IN PIPES

Journal of Mechanical Engineering ◽

10.3901/jme.2004.01.011 ◽

2004 ◽

Vol 40 (01) ◽

pp. 11 ◽

Cited By ~ 5

Author(s):

Xiuyan Wang

Keyword(s):

Guided Waves ◽

Experimental Studies ◽

Ultrasonic Guided Waves ◽

Waves Propagation

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Review on second-harmonic generation of ultrasonic guided waves in solid media (I): Theoretical analyses

Chinese Physics B ◽

10.1088/1674-1056/26/11/114302 ◽

2017 ◽

Vol 26 (11) ◽

pp. 114302 ◽

Cited By ~ 7

Author(s):

Wei-Bin Li ◽

Ming-Xi Deng ◽

Yan-Xun Xiang

Keyword(s):

Second Harmonic Generation ◽

Harmonic Generation ◽

Guided Waves ◽

Second Harmonic ◽

Ultrasonic Guided Waves ◽

Solid Media ◽

Theoretical Analyses

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Generation of cumulative second-harmonic ultrasonic guided waves with group velocity mismatching: Numerical analysis and experimental validation

EPL (Europhysics Letters) ◽

10.1209/0295-5075/116/34001 ◽

2016 ◽

Vol 116 (3) ◽

pp. 34001 ◽

Cited By ~ 14

Author(s):

Yanxun Xiang ◽

Wujun Zhu ◽

Mingxi Deng ◽

Fu-Zhen Xuan ◽

Chang-Jun Liu

Keyword(s):

Numerical Analysis ◽

Group Velocity ◽

Experimental Validation ◽

Guided Waves ◽

Second Harmonic ◽

Ultrasonic Guided Waves

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A Novel Defect Estimation Approach in Wind Turbine Blades Based on Phase Velocity Variation of Ultrasonic Guided Waves

Sensors ◽

10.3390/s21144879 ◽

2021 ◽

Vol 21 (14) ◽

pp. 4879

Author(s):

Renaldas Raišutis ◽

Kumar Anubhav Tiwari ◽

Egidijus Žukauskas ◽

Olgirdas Tumšys ◽

Lina Draudvilienė

Keyword(s):

Phase Velocity ◽

Wind Turbine ◽

Relative Error ◽

Defect Detection ◽

Guided Waves ◽

Experimental Studies ◽

Ultrasonic Guided Waves ◽

Velocity Variation ◽

Relative Errors ◽

New Criterion

The reliability of the wind turbine blade (WTB) evaluation using a new criterion is presented in the work. Variation of the ultrasonic guided waves (UGW) phase velocity is proposed to be used as a new criterion for defect detection. Based on an intermediate value between the maximum and minimum values, the calculation of the phase velocity threshold is used for defect detection, location and sizing. The operation of the proposed technique is verified using simulation and experimental studies. The artificially milled defect having a diameter of 81 mm on the segment of WTB is used for verification of the proposed technique. After the application of the proposed evaluation technique for analysis of the simulated B-scan image, the coordinates of defect edges have been estimated with relative errors of 3.7% and 3%, respectively. The size of the defect was estimated with a relative error of 2.7%. In the case of an experimentally measured B-scan image, the coordinates of defect edges have been estimated with relative errors of 12.5% and 3.9%, respectively. The size of the defect was estimated with a relative error of 10%. The comparative results obtained by modelling and experiment show the suitability of the proposed new criterion to be used for the defect detection tasks solving.

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A Time-Frequency Independent Component Analysis Method for Group Velocity Extraction of Ultrasonic Guided Waves

2019 IEEE International Ultrasonics Symposium (IUS) ◽

10.1109/ultsym.2019.8925970 ◽

2019 ◽

Author(s):

Sijia Lou ◽

Kailiang Xu ◽

Xue Jiang ◽

Bo Hu ◽

Lawrence H. Le ◽

...

Keyword(s):

Independent Component Analysis ◽

Group Velocity ◽

Guided Waves ◽

Independent Component ◽

Ultrasonic Guided Waves ◽

Analysis Method ◽

Time Frequency ◽

Frequency Independent ◽

Independent Component Analysis Method ◽

Velocity Extraction

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The use of ultrasonic guided waves for the inspection of square tube structures: Dispersion analysis and numerical and experimental studies

Structural Health Monitoring ◽

10.1177/1475921720919697 ◽

2020 ◽

pp. 147592172091969 ◽

Cited By ~ 1

Author(s):

Xiang Wan ◽

Meiru Liu ◽

Xuhui Zhang ◽

Hongwei Fan ◽

Peter W Tse ◽

...

Keyword(s):

Guided Waves ◽

Plane Surface ◽

Group Velocity Dispersion ◽

Ultrasonic Inspection ◽

Experimental Studies ◽

Wave Mode ◽

Guided Wave ◽

Ultrasonic Guided Waves ◽

Inspection Method ◽

Through Hole

Square steel tubes have been widely used in buildings and machines in civil engineering. The inspection of square tubes is becoming increasingly urgent and important to ensure the safety of these buildings and machines. However, the current most frequently used traditional ultrasonic inspection method is time-consuming and inefficient when dealing with long square tubes. There is an urgent need to develop an efficient approach to inspect square tubes. In this article, the use of ultrasonic guided waves is proposed. Phase and group velocity dispersion curves of square tube structures are first derived using the semi-analytical finite element method. An appropriate guided wave mode used for inspecting square tubes is selected. Ultrasonic guided waves propagating in normal, in-plane surface-damaged, and edge-damaged square tubes are numerically studied. It is illustrated that the monitoring points are able to receive reflected wave signals from both the in-plane surface and the edge damages. Experimental studies are also conducted to study ultrasonic guided waves interacting with circular through-hole damages located in surfaces and slot damages at edges. It is shown that both the circular through-hole damages located in different surfaces and slot damages at different edges can be clearly detected by reflected guided wave packets. It is found that the signal-to-noise ratios have been significantly improved after applying impedance matching to piezoelectric wafer transducers. The results have shown that ultrasonic guided waves are a promising and effective method for the inspection of square tubes.

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A Graphical Analysis Method of Guided Wave Modes in Rails

Applied Sciences ◽

10.3390/app9081529 ◽

2019 ◽

Vol 9 (8) ◽

pp. 1529 ◽

Cited By ~ 1

Author(s):

Xining Xu ◽

Bo Xing ◽

Lu Zhuang ◽

Hongmei Shi ◽

Liqiang Zhu

Keyword(s):

Image Processing ◽

Guided Waves ◽

Wave Mode ◽

Graphical Analysis ◽

Guided Wave ◽

Ultrasonic Guided Waves ◽

Mode Shapes ◽

Analysis Method ◽

Processing Methods ◽

Wave Modes

The cross-section of a rail has a complex geometry, and there are many propagating modes of ultrasonic guided waves in a rail. The analysis of mode shapes or the cross-sectional wave structure is of high significance to the design of an appropriate wave excitation approach for long-range defect detection of a rail. Traditionally, the semi-analytical finite elements (SAFE) method is used to obtain ultrasonic guided waves’ dispersion curves of a rail. Then, through solving the eigenvectors, it is able to calculate the displacement values of discrete nodes in three degrees of freedom (DOFs) and further obtain the wave structures. In this paper, a graphical analysis method of guided wave mode shapes is proposed. The displacements of each node in three DOFs are converted into Red Green Blue (RGB) image pixels, and the complex vibration vector data is expressed by an image. Therefore, the graphical analysis of mode shapes can be realized by using conventional image processing methods without the design of special data processing algorithms. This will improve the processing efficiency, and it is more intuitive and easier to analyze the vibration displacements represented by the image. The simulation results show that the proposed graphical analysis method can quickly and precisely locate the excitation position of the guided wave mode in the rail. By adopting image processing methods, such as the K-means clustering algorithm, the guided wave modes at a 35 kHz frequency in a rail are classified according to their mode shapes. Classification is essential for exploring the relations and fundamentals of vibrations in modes. The graphical analysis method proposed in this paper provides a novel method for the mode analysis of guided waves in rails.

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