Phase velocity estimation technique based on adaptive beamforming for ultrasonic guided waves propagating along cortical long bones

2017 ◽  
Vol 56 (7S1) ◽  
pp. 07JF06 ◽  
Author(s):  
Shigeaki Okumura ◽  
Vu-Hieu Nguyen ◽  
Hirofumi Taki ◽  
Guillaume Haïat ◽  
Salah Naili ◽  
...  
2020 ◽  
Vol 10 (23) ◽  
pp. 8397
Author(s):  
Anurup Guha ◽  
Michael Aynardi ◽  
Parisa Shokouhi ◽  
Cliff J. Lissenden

The hollow long bones of the human appendicular skeleton are known to support the propagation of ultrasonic guided waves, whose potential for diagnosing bone health is being investigated. In this study, ultrasonic guided waves propagating in the diaphysis of human tibia are characterized experimentally and numerically in the frequency range around 200 kHz. The experiment involves a unique combination of omni-directional shear transducer-based excitation and detection using a 1D laser Doppler vibrometer. The cluster of phase velocities obtained from a linear array of time-history data using space-time Fourier transform is found to be in the non-dispersive low-phase velocity region of the dispersion curves obtained for a tibial cross-section. Time-domain finite element analysis revealed that the displacement components normal to the surface are significant, even though the loading is from a shear transducer. Furthermore, semi-analytical finite element analysis revealed that the wave structures of the wave modes contained within the cluster of low-phase velocity modes are consistent with the displacement profiles obtained from the time-domain analysis. The experimental results show that the low-phase velocity mode cluster has sufficient intensity to propagate axially at least 85 mm in the mid-diaphyseal region.


2010 ◽  
Author(s):  
L. De Marchi ◽  
E. Baravelli ◽  
K. Xu ◽  
D. Ta ◽  
N. Speciale ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4879
Author(s):  
Renaldas Raišutis ◽  
Kumar Anubhav Tiwari ◽  
Egidijus Žukauskas ◽  
Olgirdas Tumšys ◽  
Lina Draudvilienė

The reliability of the wind turbine blade (WTB) evaluation using a new criterion is presented in the work. Variation of the ultrasonic guided waves (UGW) phase velocity is proposed to be used as a new criterion for defect detection. Based on an intermediate value between the maximum and minimum values, the calculation of the phase velocity threshold is used for defect detection, location and sizing. The operation of the proposed technique is verified using simulation and experimental studies. The artificially milled defect having a diameter of 81 mm on the segment of WTB is used for verification of the proposed technique. After the application of the proposed evaluation technique for analysis of the simulated B-scan image, the coordinates of defect edges have been estimated with relative errors of 3.7% and 3%, respectively. The size of the defect was estimated with a relative error of 2.7%. In the case of an experimentally measured B-scan image, the coordinates of defect edges have been estimated with relative errors of 12.5% and 3.9%, respectively. The size of the defect was estimated with a relative error of 10%. The comparative results obtained by modelling and experiment show the suitability of the proposed new criterion to be used for the defect detection tasks solving.


Author(s):  
L. De Marchi ◽  
Kailiang Xu ◽  
De-an Ta ◽  
A. Marzani ◽  
S. Caporale ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Ying Li ◽  
Dan Liu ◽  
Kailiang Xu ◽  
Dean Ta ◽  
Lawrence H. Le ◽  
...  

Ultrasonic guided waves have recently been used in fracture evaluation and fracture healing monitoring. An axial transmission technique has been used to quantify the impact of the gap breakage width and fracture angle on the amplitudes of low order guided wave modesS0andA0under a 100 kHz narrowband excitation. In our two dimensional finite-difference time-domain (2D-FDTD) simulation, the long bones are modeled as three layers with a soft tissue overlay and marrow underlay. The simulations of the transversely and obliquely fractured long bones show that the amplitudes of bothS0andA0decrease as the gap breakage widens. Fixing the crack width, the increase of the fracture angle relative to the cross section perpendicular to the long axis enhances the amplitude ofA0, while the amplitude ofS0shows a nonmonotonic trend with the decrease of the fracture angle. The amplitude ratio between theS0andA0modes is used to quantitatively evaluate the fracture width and angles. The study suggests that the low order guided wave modesS0andA0have potentials for transverse and oblique bone fracture evaluation and fracture healing monitoring.


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