Laser ultrasonic anomalous wave propagation imaging method with adjacent wave subtraction: Application to actual damages in composite wing

2012 ◽  
Vol 44 (2) ◽  
pp. 428-440 ◽  
Author(s):  
Chen Ciang Chia ◽  
Jung-Ryul Lee ◽  
Chan-Yik Park ◽  
Hyo-Mi Jeong
Keyword(s):  
Wave Propagation ◽  
Imaging Method ◽  
Laser Ultrasonic ◽  
Anomalous Wave ◽  
Composite Wing

Laser ultrasonic anomalous wave propagation imaging method with adjacent wave subtraction: Algorithm

2012 ◽  
Vol 44 (5) ◽  
pp. 1507-1515 ◽  
Author(s):  
Jung-Ryul Lee ◽  
Chen Ciang Chia ◽  
Chan-Yik Park ◽  
Hyomi Jeong
Keyword(s):  
Wave Propagation ◽  
Imaging Method ◽  
Laser Ultrasonic ◽  
Anomalous Wave

scholarly journals FEA-Based Ultrasonic Focusing Method in Anisotropic Media for Phased Array Systems

2021 ◽  
Vol 11 (19) ◽  
pp. 8888
Author(s):  
Seongin Moon ◽  
To Kang ◽  
Soonwoo Han ◽  
Kyung-Mo Kim ◽  
Hyung-Ha Jin ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Ultrasonic Wave ◽  
Elastic Constants ◽  
Grain Orientation ◽  
Phased Array ◽  
Ultrasonic Imaging ◽  
Anisotropic Media ◽  
Imaging Method ◽  
Ultrasonic Wave Propagation ◽  
Propagation Paths

Traditional ultrasonic imaging methods have a low accuracy in the localization of defects in austenitic welds because the anisotropy and inhomogeneity of the welds cause distortion of the ultrasonic wave propagation paths in anisotropic media. The distribution of the grain orientation in the welds influences the ultrasonic wave velocity and ultrasonic wave propagation paths. To overcome this issue, a finite element analysis (FEA)-based ultrasonic imaging methodology for austenitic welds is proposed in this study. The proposed ultrasonic imaging method uses a wave propagation database to synthetically focus the inter-element signal recorded with a phased array system using a delay-and-sum strategy. The wave propagation database was constructed using FEA considering the grain orientation distribution and the anisotropic elastic constants in the welds. The grain orientation was extracted from a macrograph obtained from a dissimilar metal weld specimen, after which the elastic constants were optimized using FEA with grain orientation information. FEA was performed to calculate a full matrix of time-domain signals for all combinations of the transmitting and receiving elements in the phased array system. The proposed approach was assessed for an FEA-based simulated model embedded in a defect. The simulation results proved that the newly proposed ultrasonic imaging method can be used for defect localization in austenitic welds.

An optimized laser ultrasonic synthetic aperture imaging method using differential technique

2021 ◽  
pp. 2150345
Author(s):  
Zhengliang Hu ◽  
Jinxing Huang ◽  
Pan Xu ◽  
Kang Lou ◽  
Min Zhu ◽  
...  
Keyword(s):  
Element Model ◽  
Original Data ◽  
High Amplitude ◽  
Synthetic Aperture ◽  
Imaging Method ◽  
Internal Defects ◽  
Laser Ultrasonic ◽  
Synthetic Aperture Imaging ◽  
Reflected Waves ◽  
Differential Technique

Laser ultrasonic synthetic aperture focusing technique (SAFT) is susceptible to multiple modes of ultrasonic generated by laser pulse. In this work, we propose an optimized synthetic aperture imaging method based on the differential technique, resulting in the effective detection of internal defects. The laser ultrasonic SAFT finite element model is established, and the models are calculated in the case of existing internal defect or not. Thereby, the original ultrasonic data containing the defect reflected waves and the differential data are obtained, and the internal defects are reconstructed by the delay superposition algorithm. The results show that the defect imaging is submerged in the high-amplitude background noise superimposed by the surface acoustic wave; when only the original data are used. However, the optimized SAFT imaging based on the differential technique can not only reduce the interference of other mode waves on the imaging area significantly, but also retain the defect reflected waves effectively. Moreover, the imaging and precise locating of multiple defects are realized, which pave the way for enhancing the internal defects detection ability of laser ultrasonic.

scholarly journals Artificial Intelligence-Based Bolt Loosening Diagnosis Using Deep Learning Algorithms for Laser Ultrasonic Wave Propagation Data

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5329
Author(s):  
Dai Quoc Tran ◽  
Ju-Won Kim ◽  
Kassahun Demissie Tola ◽  
Wonkyu Kim ◽  
Seunghee Park
Keyword(s):  
Neural Network ◽  
Signal Processing ◽  
Wave Propagation ◽  
Deep Learning ◽  
Ultrasonic Wave ◽  
Ultrasonic Waves ◽  
Support Vector ◽  
Laser Ultrasonic ◽  
Data Set ◽  
Ultrasonic Wave Propagation

The application of deep learning (DL) algorithms to non-destructive evaluation (NDE) is now becoming one of the most attractive topics in this field. As a contribution to such research, this study aims to investigate the application of DL algorithms for detecting and estimating the looseness in bolted joints using a laser ultrasonic technique. This research was conducted based on a hypothesis regarding the relationship between the true contact area of the bolt head-plate and the guided wave energy lost while the ultrasonic waves pass through it. First, a Q-switched Nd:YAG pulsed laser and an acoustic emission sensor were used as exciting and sensing ultrasonic signals, respectively. Then, a 3D full-field ultrasonic data set was created using an ultrasonic wave propagation imaging (UWPI) process, after which several signal processing techniques were applied to generate the processed data. By using a deep convolutional neural network (DCNN) with a VGG-like architecture based regression model, the estimated error was calculated to compare the performance of a DCNN on different processed data set. The proposed approach was also compared with a K-nearest neighbor, support vector regression, and deep artificial neural network for regression to demonstrate its robustness. Consequently, it was found that the proposed approach shows potential for the incorporation of laser-generated ultrasound and DL algorithms. In addition, the signal processing technique has been shown to have an important impact on the DL performance for automatic looseness estimation.

DEVELOPMENT OF A GENERIC ULTRASOUND VIBRO-ACOUSTIC IMAGING PLATFORM FOR TISSUE ELASTICITY AND VISCOSITY

2012 ◽  
Vol 05 (01) ◽  
pp. 1250002
Author(s):  
YI WANG ◽  
SIPING CHEN ◽  
TIANFU WANG ◽  
TING ZHOU ◽  
QIAOLIANG LI ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Shear Wave ◽  
Acoustic Imaging ◽  
Phase Changes ◽  
Propagation Path ◽  
Imaging Method ◽  
Tissue Elasticity ◽  
Shear Wave Speed ◽  
Early Diagnosis Of Cancer

Tissue elasticity and viscosity are always associated with pathological changes. As a new imaging method, ultrasound vibro-acoustic imaging is developed for quantitatively measuring tissue elasticity and viscosity which have important significance in early diagnosis of cancer. This paper developed an ultrasound vibro-acoustic imaging research platform mainly consisting of excitation part and detection part. The excitation transducer was focused at one location within the medium to generate harmonic vibration and shear wave propagation, and the detection transducer was applied to detect shear wave at other locations along shear wave propagation path using pulse-echo method. The received echoes were amplified, filtered, digitized and then processed by Kalman filter to estimate the vibration phase. According to the phase changes between different propagation locations, we estimated the shear wave speed, and then used it to calculate the tissue elasticity and viscosity. Preliminary phantom experiments based on this platform show results of phantom elasticity and viscosity close to literature values. Upcoming experiments are now in progress to obtain quantitative elasticity and viscosity in vitro tissue.

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