scholarly journals Experimental study of guided waves propagation characteristics under the changing temperatures

2018 ◽  
Vol 20 ◽  
pp. 208-212
Author(s):  
Lei Qiu ◽  
Xixi Yan ◽  
Shenfang Yuan
2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Jing Ni ◽  
Shaoping Zhou ◽  
Pugen Zhang ◽  
Yong Li

Ultrasonic guided waves is one of the most effective nondestructive testing techniques, which has been successfully applied for damage detection and evaluation of piping components. However, research about defects detection for pipelines with multiple bends is still limited. In this paper, effect of pipe bend arrangement on guided waves-based defect detection is investigated by experimental method, in which different configurations including space-Z type, U type, and plane-Z type are considered, respectively. Finite element (FE) simulation is used to explore the propagation behaviors of axisymmetric L (0, 2) mode in different bend configurations. On this basis, the detection sensitivity for different crack locations is experimentally investigated. Simulation and experiment results reveal that feature of guided waves propagation across the first and the second bend is totally different, and the defect detection sensitivity in the second bend is different from that in the first bend.


2019 ◽  
Vol 32 (2) ◽  
pp. 385-397 ◽  
Author(s):  
Jia-yi Xu ◽  
Shu-xue Liu ◽  
Jin-xuan Li ◽  
Wei Jia

Author(s):  
Shuangmiao Zhai ◽  
Chaofeng Chen ◽  
Gangyi Hu ◽  
Shaoping Zhou

Pressure vessels are normally employed under extreme environments with high temperature and high pressure. Inevitably, the defects like crack and corrosion that easily occur in the equipment and can significantly influence the normal operation. Guided wave-based method is a cost-effective means to measure the utility of pressure vessel. In this paper, finite element (FE) simulation is used to explore the propagation characteristics of circumferential guided waves in pressure vessel. Based on the propagation characteristics, the experiments with different configurations of piezoelectric transducers (PETs), which contain a sparse array and a dense array, have been conducted on pressure vessel respectively. Different imaging methods, including discrete ellipse imaging algorithm and probability damage imaging algorithm have been applied to locate the defect based on the configurations above. Furthermore, a multi-channel ultrasonic guided wave detection system has been set up for pressure vessel inspection. The experimental results show that the sparse array with the discrete ellipse imaging algorithm can locate the defect effectively. The imaging results based on probability damage imaging algorithm show that the dense array presents the better localization result.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Zhupeng Zheng ◽  
Ying Lei

Techniques based on ultrasonic guided waves (UGWs) play important roles in the structural health monitoring (SHM) of large-scale civil infrastructures. In this paper, dispersion equations of longitudinal wave propagation in reinforced concrete member are investigated for the purpose of monitoring steels embedded in concrete. For a steel bar embedded in concrete, not the velocity but the attenuation dispersion curves will be affected by the concrete. The effects of steel-to-concrete shear modulus ratio, density ratio, and Poisson’s ratio on propagation characteristics of guided wave in steel bar embedded in concrete were studied by the analysis of the real and imaginary parts of the wave number. The attenuation characteristics of guided waves of steel bar in different conditions including different bar concrete constraint and different diameter of steel bar are also analyzed. Studies of the influence of concrete on propagation characteristics of guided wave in steel bars embedded in concrete will increase the accuracy in judging the structure integrity and promote the level of defect detection for the steel bars embedded in concrete.


2020 ◽  
Vol 56 (2) ◽  
pp. 141-150
Author(s):  
S. Taleb ◽  
L. Rittmeier ◽  
M. Sinapius ◽  
F. Boubenider ◽  
D. Schmidt

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