Influence of modal characteristics of a partially debonded piezoelectric transducer in higher and subharmonic modes generated in Lamb wave

2018 ◽  
Vol 25 (10) ◽  
pp. e2239 ◽  
Author(s):  
Anurup Guha ◽  
C. R. Bijudas
Author(s):  
Alisa N Shpak ◽  
Mikhail V Golub ◽  
Inka Mueller ◽  
Artem Eremin ◽  
Jens Kathol ◽  
...  

This article presents the results of theoretical and experimental investigations of characteristic changes of Lamb wave excitation and scattering by a strip-like horizontal delamination in a layered elastic waveguide for Lamb waves induced by a piezoelectric wafer active sensor. The boundary integral equation method is used to describe wave propagation in an infinite layered waveguide with a delamination, while the frequency domain spectral element method is employed to model the dynamic behaviour of the piezoelectric wafer active sensor, which allows to simulate debonding between the piezoelectric wafer active sensor and the waveguide. Experimental investigations of the dynamic interaction of the piezoelectric wafer active sensor with a layered plate containing a horizontal delamination is conducted for several damage scenarios, showing a good agreement with the results obtained using the developed mathematical model. The obtained mathematical model is employed to analyse alteration of the piezo-induced Lamb waves including modes’ decomposition due to delamination. The conversion and/or conservation of the Lamb waves on account of a delamination is investigated. The electro-mechanical impedance of the piezoelectric transducer and the stress intensity factors of a delamination are analysed in dependence on the delamination location.


2011 ◽  
Vol 83 ◽  
pp. 267-273
Author(s):  
S. Saravanan ◽  
K.R. Natarajan ◽  
J.L. Yang ◽  
B. S. Wong ◽  
N. Q. Guo

This paper is aimed at experimentally developing an in-situ macro-fibre composite (MFCTM) piezoelectric transducer sparse array which functions as both actuator and sensor of Lamb wave for damage detection in composite laminate. Lamb waves which have been used in non-destructive evaluation (NDE) of plate-like structures, can be used for active monitoring and interrogating the health of the structures due to their long range propagation with less attenuation. MFC acting as a powerful actuator of Lamb wave as well as a sensitive sensor is highly conformable and anisotropic in behaviour compared to monolithic piezoelectric transducer. The surface bonded MFC transducer on woven carbon fibre reinforced plastic (CFRP) laminate shows directional Lamb wave generation and reception characteristics. Pitch catch approach is used for low velocity impact damage detection. The MFC sensor shows a drastic drop in signal amplitude with the growth of the impact damage.


1997 ◽  
Vol 82 (5) ◽  
pp. 2049-2055 ◽  
Author(s):  
Emmanuel Moulin ◽  
Jamal Assaad ◽  
Christophe Delebarre ◽  
Henri Kaczmarek ◽  
Daniel Balageas

1996 ◽  
Vol 8 (1) ◽  
pp. 189-197
Author(s):  
J. Pei ◽  
M. I. Yousuf ◽  
F. L. Degertekin ◽  
B. V. Honein ◽  
B. T. Khuri-Yakub

Author(s):  
Nik Ahmad Zainal Abidin ◽  
◽  
Norkharziana Mohd Nayan ◽  
Azuwa Ali ◽  
N. A. Azli ◽  
...  

This research presents a simulation analysis for the AC-DC converter circuit with a different configurations of the array connection of the piezoelectric sensor. The selection of AC-DC converter circuits is full wave bridge rectifier (FWBR), parallel SSHI (P-SSHI) and parallel voltage multiplier (PVM) with array configuration variation in series (S), parallel (P), series-parallel (SP) and parallel-series (PS). The system optimizes with different load configurations ranging from 10 kΩ to 1 MΩ. The best configuration of AC-DC converter with an appropriate array piezoelectric connection producing the optimum output of harvested power is presented. According to the simulation results, the harvested power produced by using P-SSHI converter connected with 3 parallel piezoelectric transducer array was 85.9% higher than for PVM and 15.88% higher than FWBR.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1736
Author(s):  
Zengchong Yang ◽  
Xiucheng Liu ◽  
Bin Wu ◽  
Ren Liu

Previous studies on Lamb wave touchscreen (LWT) were carried out based on the assumption that the unknown touch had the consistent parameters with acoustic fingerprints in the reference database. The adaptability of LWT to the variations in touch force and touch area was investigated in this study for the first time. The automatic collection of the databases of acoustic fingerprints was realized with an experimental prototype of LWT employing three pairs of transmitter–receivers. The self-adaptive updated weight coefficient of the used transmitter–receiver pairs was employed to successfully improve the accuracy of the localization model established based on a learning method. The performance of the improved method in locating single- and two-touch actions with the reference database of different parameters was carefully evaluated. The robustness of the LWT to the variation of the touch force varied with the touch area. Moreover, it was feasible to locate touch actions of large area with reference databases of small touch areas as long as the unknown touch and the reference databases met the condition of equivalent averaged stress.


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