Reverberation-based high-speed guided-wave ultrasonic propagation imager for structural inspection of thick composites

2021 ◽  
Vol 259 ◽  
pp. 113446
Author(s):  
Joonhee Joh ◽  
Yunshil Choi ◽  
Jung-Ryul Lee
Keyword(s):  
High Speed ◽  
Guided Wave ◽  
Ultrasonic Propagation ◽  
Thick Composites ◽  
Structural Inspection

scholarly journals Defect Visualization of a Steel Structure Using a Piezoelectric Line Sensor Based on Laser Ultrasonic Guided Wave

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3992 ◽  
Author(s):  
Sang-Hyeon Kang ◽  
Dae-Hyun Han ◽  
Lae-Hyong Kang
Keyword(s):  
Large Scale ◽  
Steel Structure ◽  
Piezoelectric Sensor ◽  
Guided Wave ◽  
Laser Ultrasonic ◽  
Thermoelastic Wave ◽  
Multiple Sensors ◽  
Ultrasonic Guided Wave ◽  
Defect Area ◽  
Ultrasonic Propagation

We studied the detection and visualization of defects in a test object using a laser ultrasonic guided wave. The scan area is irradiated by a laser generated from a Nd:YAG 532 nm Q-switched laser generator through a galvanometer scanner. The laser irradiation causes the surface temperature to suddenly rise and then become temporarily adiabatic. The locally heated region reaches thermal equilibrium with the surroundings. In other words, heat energy propagates inside the object in the form of elastic energy through adiabatic expansion. This thermoelastic wave is typically acquired by a piezoelectric sensor, which is sensitive in the ultrasonic domain. A single piezoelectric sensor has limited coverage in the scan area, while multi-channel piezoelectric sensors require many sensors, large-scale wiring, and many channeling devices for use and installation. In addition, the sensors may not acquire signals due to their installed locations, and the efficiency may be reduced because of the overlap between the sensing areas of multiple sensors. For these reasons, the concept of a piezoelectric line sensor is adopted in this study for the first time. To verify the feasibility of the line sensor, I- and L-shaped sensors were attached to a steel structure, and the ultrasound signal from laser excitation was obtained. If the steel structure has defects on the back, the ultrasonic propagation image will be distorted in the defect area. Thus, we can detect the defects easily from the visualization image. Three defects were simulated for the test. The results show that the piezoelectric line sensor can detect defects more precisely and accurately compared to a single piezoelectric sensor.

The Non-Destructive Measurement Instrument for Material Thickness

2011 ◽  
Vol 480-481 ◽  
pp. 415-420 ◽  
Author(s):  
Shou Cheng Ding ◽  
Wen Hui Li ◽  
Gui Ci Yuan
Keyword(s):  
High Speed ◽  
Low Cost ◽  
Measurement Instrument ◽  
Measurement Range ◽  
Measuring Instrument ◽  
Ultrasonic Probe ◽  
Counter Circuit ◽  
Ultrasonic Propagation ◽  
Destructive Measurement ◽  
Non Destructive

In a variety of materials, the ultrasonic propagation velocity is different. Using ultrasonic reflection principle in the material, the measuring instrument detected the thickness of the measured object. AT89C51 microcontroller as the system core, with ultrasonic probe, transmitter circuit, receiver circuit, counter circuit, LCD display circuit together, completed the measurement of materials thickness. The measurement range was up to a 1.2 ~ 200mm. Practice shows that the instrument is low cost, high speed, high precision, reliability, adaptability, etc. So it has broad application prospects.

Guided wave propagation in high-speed train axle and damage detection based on wave mode conversion

2015 ◽  
Vol 22 (9) ◽  
pp. 1133-1147 ◽  
Author(s):  
Fucai Li ◽  
Xuewei Sun ◽  
Jianxi Qiu ◽  
Limin Zhou ◽  
Hongguang Li ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Damage Detection ◽  
High Speed ◽  
Mode Conversion ◽  
Wave Mode ◽  
Guided Wave ◽  
High Speed Train ◽  
Guided Wave Propagation

scholarly journals Non-Contact Ultrasonic Guided Wave Inspection of Rails: Next Generation Approach

2016 ◽  
Author(s):  
Stefano Mariani ◽  
Thompson V. Nguyen ◽  
Xuan Zhu ◽  
Simone Sternini ◽  
Francesco Lanza di Scalea ◽  
...  
Keyword(s):  
High Speed ◽  
Rail Steel ◽  
Signal To Noise Ratio ◽  
False Positive Rate ◽  
Impedance Matching ◽  
Roc Curves ◽  
Guided Wave ◽  
Lessons Learned ◽  
Ultrasonic Guided Wave ◽  
Positive Rate

The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is developing a system for high-speed and non-contact rail defect detection. A prototype using an ultrasonic air-coupled guided wave signal generation and air-coupled signal detection, paired with a real-time statistical analysis algorithm, has been realized. This system requires a specialized filtering approach based on electrical impedance matching due to the inherently poor signal-to-noise ratio of air-coupled ultrasonic measurements in rail steel. Various aspects of the prototype have been designed with the aid of numerical analyses. In particular, simulations of ultrasonic guided wave propagation in rails have been performed using a Local Interaction Simulation Approach (LISA) algorithm. The system’s operating parameters were selected based on Receiver Operating Characteristic (ROC) curves, which provide a quantitative manner to evaluate different detection performances based on the trade-off between detection rate and false positive rate. The prototype based on this technology was tested in October 2014 at the Transportation Technology Center (TTC) in Pueblo, Colorado, and again in November 2015 after incorporating changes based on lessons learned.

Non-Contact Ultrasonic Guided Wave Inspection of Rails

2013 ◽  
Author(s):  
Thompson V. Nguyen ◽  
Stefano Mariani ◽  
Robert R. Phillips ◽  
Piotr Kijanka ◽  
Francesco Lanza di Scalea ◽  
...  
Keyword(s):  
High Speed ◽  
Surface Characterization ◽  
Rail Steel ◽  
Signal To Noise Ratio ◽  
High Reliability ◽  
False Positive Rate ◽  
Experimental Tests ◽  
Roc Curves ◽  
Guided Wave ◽  
Ultrasonic Guided Wave

The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is developing a system for high-speed and non-contact rail integrity evaluation. A prototype using an ultrasonic air-coupled guided wave signal generation and air-coupled signal detection, in pair with a real-time statistical analysis algorithm, is being developed. This solution presents an improvement over the previously considered laser/air-coupled hybrid system because it replaces the costly and hard-to-maintain laser with a much cheaper, faster, and easier-to-maintain air-coupled transmitter. This system requires a specialized filtering approach due to the inherently poor signal-to-noise ratio of the air-coupled ultrasonic measurements in rail steel. Various aspects of the prototype have been designed with the aid of numerical analyses. In particular, simulations of ultrasonic guided wave propagation in rails have been performed using a Local Interaction Simulation Approach (LISA) algorithm. Many of the system operating parameters were selected based on Receiver Operating Characteristic (ROC) curves, which provide a quantitative manner to evaluate different detection performances based on the trade-off between detection rate and false positive rate. Experimental tests have been carried out at the UCSD Rail Defect Farm. The laboratory results indicate that the prototype is able to detect internal rail defects with a high reliability. A field test will be planned later in the year to further validate these results. Extensions of the system are planned to add rail surface characterization to the internal rail defect detection.

scholarly journals Study on the ultrasonic guided wave and online visual monitoring for ultrasonic precise bonding

2021 ◽  
Author(s):  
Yibo Sun ◽  
Mengruo Cao ◽  
Li Zou ◽  
Xinhua Yang
Keyword(s):  
High Speed ◽  
Wavelet Packet ◽  
Melting Zone ◽  
Guided Wave ◽  
Frequency Characteristics ◽  
Bonding Process ◽  
Visual Monitoring ◽  
Time Frequency ◽  
Ultrasonic Bonding ◽  
Ultrasonic Guided Wave

Abstract Ultrasonic precise bonding is an emerging technology in the application of polymer micro-assembly. In the ultrasonic bonding process, the propagation of ultrasound varies with the change of the interfacial polymer physical state. So the ultrasonic guided wave is an effective parameter to in-situ monitor the fusion degree. The ultrasonic guided wave in the ultrasonic bonding process is studied by vibration analysis and online visual monitoring in this paper. The time-frequency characteristics in the ultrasonic guided wave in the bonding process are mainly analyzed by Fast Fourier Transform spectrum analysis, Wavelet Packet Decomposition, and envelope spectrum methods. The polymer interfacial fusion is monitored by the high-speed HD camera in the ultrasonic bonding process. The time-frequency characteristics in the ultrasonic guided wave and the fusion behavior of the thermal melt interface are analyzed and correlated. Results indicate that the change of the interfacial thermal melt state is related to the time-frequency characteristics of the ultrasonic guided wave. The fusion of the melting zone, the rotation of the micro-device, the generation or disappearance of local air bubbles all lead to the changing of the harmonic frequency and intensity in the ultrasonic bonding process.

Resonant modulation

1984 ◽  
Vol 313 (1525) ◽  
pp. 401-403 ◽  
Keyword(s):  
High Speed ◽  
Guided Wave ◽  
Modulation Bandwidth ◽  
Drive Power ◽  
Light Waves ◽  
Electro Optic ◽  
Alternative Approach ◽  
Potential Applications ◽  
Waveguide Cavities ◽  
Rc Constant

Devices that offer fast modulation and switching of light waves currently attract widespread research efforts for potential applications in high-speed signal processing. The guided-wave techniques of integrated optics have demonstrated the capability to achieve drive power/bandwidth levels of a few milliwatts per gigahertz modulation bandwidth. Most recently, efforts have been concentrated on electro-optic travellingwave configurations (Alferness et al . 1983; Gee & Thurmond 1983; Cross et al . 1984) to achieve operation at higher frequencies with higher bandwidths than are usually obtainable from lumped-electrode devices, wherein the dominant restriction of the speed of operation is the RC constant associated with electrode charging and discharging. Here, we discuss the potential merits of an alternative approach, which employs resonant optical waveguide cavities.

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