Phased array tuning for optimal ultrasonic guided wave mode selection

2014 ◽  
Author(s):  
J. H. Bostron ◽  
J. L. Rose ◽  
C. A. Moose
Keyword(s):  
Phased Array ◽  
Mode Selection ◽  
Wave Mode ◽  
Guided Wave ◽  
Ultrasonic Guided Wave

scholarly journals Phase-delayed laser diode array allows ultrasonic guided wave mode selection and tuning

2013 ◽  
Vol 113 (14) ◽  
pp. 144904 ◽  
Author(s):  
Pasi Karppinen ◽  
Ari Salmi ◽  
Petro Moilanen ◽  
Timo Karppinen ◽  
Zuomin Zhao ◽  
...  
Keyword(s):  
Laser Diode ◽  
Mode Selection ◽  
Wave Mode ◽  
Guided Wave ◽  
Diode Array ◽  
Laser Diode Array ◽  
Ultrasonic Guided Wave

scholarly journals An Ultrasonic Guided Wave Mode Selection and Excitation Method in Rail Defect Detection

2019 ◽  
Vol 9 (6) ◽  
pp. 1170 ◽  
Author(s):  
Hongmei Shi ◽  
Lu Zhuang ◽  
Xining Xu ◽  
Zujun Yu ◽  
Liqiang Zhu
Keyword(s):  
Mode Shape ◽  
Strain Energy ◽  
Mode Selection ◽  
Wave Mode ◽  
Guided Wave ◽  
Rail Head ◽  
Ultrasonic Guided Wave ◽  
Phase Velocity Dispersion ◽  
Excitation Method ◽  
Shape Data

Different guided wave mode has different sensitivity to the defects of rail head, rail web and rail base in the detection of rail defects using ultrasonic guided wave. A novel guided wave mode selection and excitation method is proposed, which is effective for detection and positioning of the three parts of rail defects. Firstly, the mode shape data in a CHN60 rail is obtained at the frequency of 35 kHz based on SAFE method. The guided wave modes are selected, combining the strain energy distribution diagrams with the phase velocity dispersion curves of modes, which are sensitive to the defects of the rail head, rail web and rail base. Then, the optimal excitation direction and excitation node of the modes are calculated with the mode shape matrix. Phase control and time delay technology are employed to achieve the expected modes enhancement and interferential modes suppression. Finally, ANSYS is used to excite the specific modes and detect defects in different rail parts to validate the proposed methods. The results show that the expected modes are well acquired. The selected specific modes are sensitive to the defects of different positions and the positioning error is small enough for the maintenance staff to accept.

scholarly journals Development of Ultrasonic Guided Wave Transducer for Monitoring of High Temperature Pipelines

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5443 ◽  
Author(s):  
Anurag Dhutti ◽  
Saiful Asmin Tumin ◽  
Wamadeva Balachandran ◽  
Jamil Kanfoud ◽  
Tat-Hean Gan
Keyword(s):  
High Temperature ◽  
Guided Waves ◽  
Elevated Temperatures ◽  
Element Model ◽  
Wave Mode ◽  
Guided Wave ◽  
Electromechanical Impedance ◽  
Active Sensor ◽  
Ultrasonic Guided Wave ◽  
Modes Of Vibration

High-temperature (HT) ultrasonic transducers are of increasing interest for structural health monitoring (SHM) of structures operating in harsh environments. This article focuses on the development of an HT piezoelectric wafer active sensor (HT-PWAS) for SHM of HT pipelines using ultrasonic guided waves. The PWAS was fabricated using Y-cut gallium phosphate (GaPO4) to produce a torsional guided wave mode on pipes operating at temperatures up to 600 °C. A number of confidence-building tests on the PWAS were carried out. HT electromechanical impedance (EMI) spectroscopy was performed to characterise piezoelectric properties at elevated temperatures and over long periods of time (>1000 h). Laser Doppler vibrometry (LDV) was used to verify the modes of vibration. A finite element model of GaPO4 PWAS was developed to model the electromechanical behaviour of the PWAS and the effect of increasing temperatures, and it was validated using EMI and LDV experimental data. This study demonstrates the application of GaPO4 for guided-wave SHM of pipelines and presents a model that can be used to evaluate different transducer designs for HT applications.

A Study on the Behavior of Ultrasonic Guided Wave Mode in a Pipe Using a Comb Transducer

2005 ◽  
Vol 297-300 ◽  
pp. 2182-2186
Author(s):  
Ik Keun Park ◽  
Yong Kwon Kim ◽  
Youn Ho Cho ◽  
Won Joon Song ◽  
Yeon Shik Ahn ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Mode Conversion ◽  
Group Velocity Dispersion ◽  
Longitudinal Mode ◽  
Wave Mode ◽  
Guided Wave ◽  
Flexural Mode ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
Ultrasonic Guided Wave

A preliminary study of the behavior of ultrasonic guided wave mode in a pipe using a comb transducer for maintenance inspection of power plant facilities has been verified experimentally. Guided wave mode identification is carried out in a pipe using time-frequency analysis methods such as wavelet transform (WT) and short time Fourier transform (STFT), compared with theoretically calculated group velocity dispersion curves for longitudinal and flexural mode. The results are in good agreement with analytical predictions and show the effectiveness of using the time-frequency analysis method to identify the individual guided wave modes. And, It was found out that longitudinal mode (0, 1) is affected by mode conversion less than the other modes. Therefore, L (0, 1) is selected as a optimal mode for evaluating location of the surface defect in a pipe.

scholarly journals Extraction of Least-Dispersive Ultrasonic Guided Wave Mode in Rail Track Based on Floquet-Bloch Theory

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Maodan Yuan ◽  
Peter W. Tse ◽  
Weiming Xuan ◽  
Wenjin Xu
Keyword(s):  
Frequency Band ◽  
Complex Geometry ◽  
Numerical Study ◽  
Wave Mode ◽  
Guided Wave ◽  
Fe Model ◽  
Practical Applications ◽  
Rail Track ◽  
Ultrasonic Guided Wave ◽  
Full Cross Section

Ultrasonic guided wave (UGW) has shown great potential in the field of structural health monitoring of rail tracks due to its long-range capability and full cross section coverage. However, the practical application of UGW has been hindered by the complicated signal interpretation because of the natures of multiple modes and dispersion. Therefore, it is desirable that the effective UGW modes with high excitability and least dispersion can be identified and extracted for practical applications. In this paper, a numerical study on the guided wave propagation was carried out on a standard rail with 56E1 profile. Firstly, Floquet-Bloch theory was applied to obtain the dispersion curves of guided wave in a rail. Then, a 3D FE model was built to investigate the UGW propagation along the rail within the frequency range of 0–120 kHz. Wavenumber-frequency analysis method was applied to decompose and identify the propagating UGW modes. With a carefully designed 2D bandpass filter, a specific mode W0 was extracted in the wavenumber-frequency domain. Finally, a frequency band sweep technique was also proposed to get the optimal frequency band to achieve a pure and least-dispersive UGW mode along the rail web. The proposed method provides an effective way to extract efficient UGW modes to assess the integrity of the rail track, as well as other waveguides with complex geometry.

Design of Ultrasonic Guided Wave Excitation Signal Generator for Rotating Shafts

2012 ◽  
Vol 629 ◽  
pp. 570-575
Author(s):  
Xiao Yu Wang ◽  
Yan Yan Yang ◽  
Dao Shun Wang
Keyword(s):  
Surface Defects ◽  
Wave Mode ◽  
Guided Wave ◽  
Signal Generator ◽  
Wave Excitation ◽  
Rotating Shaft ◽  
Ultrasonic Guided Wave ◽  
Detection Technology ◽  
Test Component ◽  
Rotating Shafts

Ultrasonic guided wave detection technology has mangy special characteristics. It can spread very far along the components in the distance and it can throughout the whole thickness of components, so we can make use of ultrasonic guided wave to test component of internal and surface defects. The rotating shafts are the organizations widely used in the modern production but they are very easy to be dangerous faults. If we can realize the rotating shaft in time, it can reduce the danger. It is significant to design an affordable generator which produces signals to drive magnetostrictive probe that produces ultrasonic guided wave. In this paper, we choose the torsional wave as example to design signal generator. We will introduce the way to select the appropriate guided wave mode and frequency of excitation. Design signal generator with ATmega32, AD9851 and DAC0832.

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