Coating Property Effects on Guided Wave Attenuation in Viscoelastic Coated Pipes

2007 ◽  
Author(s):  
W. Luo ◽  
J. L. Rose ◽  
Y. Zhu
2012 ◽  
Vol 47 ◽  
pp. 163-170 ◽  
Author(s):  
Adam C. Cobb ◽  
Hegeon Kwun ◽  
Leonardo Caseres ◽  
George Janega

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Guodong Yue ◽  
Xiushi Cui ◽  
Ke Zhang ◽  
Zhan Wang ◽  
Dong An

In order to monitor the rail base, the dispersion characteristics and propagation properties of the guided wave are studied. Firstly, two modes named as Modes V1 and V2 are selected by the semianalytical finite element method (SAFE). The region at the bottom edge can be monitored by Mode V1, while the junction of the base edge and the flange can be detected by Mode V2. Then, the characteristics in the propagation process are analyzed using the finite element method (FEM). The two modes can be separated about 0.6 ms after they are excited. Thirdly, a wave attenuation algorithm based on mean is proposed to quantify the wave attenuation. Both waves can have weak attenuation and be detected within 5 m. Finally, a mode-identified experiment is performed to validate the aforementioned analysis. And a defect detection experiment is performed to demonstrate the excellent monitoring characteristics using Mode V2. These results can be used to monitor the rail base in practice engineering.


2008 ◽  
Vol 33-37 ◽  
pp. 285-290
Author(s):  
Yong Hong ◽  
Gao Ping Wang ◽  
Byeong Hee Han ◽  
Dong Pyo Hong ◽  
Young Moon Kim

Beam structures are a common form in many large structures, and therefore the real-time condition monitoring and active control of beams will improve the reliability and safety of many structures. This paper presents a damage assessment method which combines the impedance method and guided wave method. The combination enabled to improve the damage detection efficiency. The impedance method is used first to detect whether the damage occurs or not and judge the damage extent. The guided wave then is introduced to accurately localize damages. The improved method provides possibility for more accurately identifying and localization damages compared to that conventional method. A powerful wavelet transform is used to extract the signals efficiently. Additionally, with using the general function generator to excite the piezoceramic (PZT) patches to generate the guided wave, the guided wave propagates along with the beam structures with PZT patches bonded, and the real-time signals are recorded. Damages are indicated by a change of response signals when compared with a template undamaged condition. The wave attenuation and mode conversion is sufficient to detect various types of defects. The results show considerable ability for identifying and localization of the simulated damages.


Author(s):  
Sergey Shevtsov ◽  
Valery Chebanenko ◽  
Maria Shevtsova ◽  
Shun-Hsyung Chang ◽  
Evgenia Kirillova ◽  
...  

This paper addresses investigation of guided-wave excitation by angle-beam wedge piezoelectric transducers in multi-layered composite plate structure with orthotropic symmetry of the material. The aim of the present study is to determine the capability of such actuators to provide the controlled generation of an acoustic wave of a desirable type with the necessary wavelength, propagation distance and directivity. The studied CFRP panel is considered as homogenous with effective elastic moduli and anisotropic structural damping, whose parameters were determined experimentally. According to the results of dispersion analysis and taking into account the data of wave attenuation in a highly damping CFRP composite, the two types of propagating waves A0 and S0 were considered theoretically and experimentally in the frequency range 10 - 100 kHz. Using the results of a previous study, the structure of the wedge actuator was reconstructed to develop its finite element (FE) model, and a modal analysis was carried out, which revealed the most intense natural vibration modes and their eigenfrequencies within the used frequency range. Both experimental and numerical studies of the generation, propagation, directivity and attenuation of waves in the orthotropic composite panel under study revealed the influence of the angular orientation of the actuator on the formation of wave patterns and allowed to determine the capabilities of the wave's directivity control.


2017 ◽  
Author(s):  
Tomasz Wandowski ◽  
Pawel Kudela ◽  
Pawel Malinowski ◽  
Wieslaw Ostachowicz

2016 ◽  
Author(s):  
Eli Leinov ◽  
Peter Cawley ◽  
Michael J. S. Lowe
Keyword(s):  

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