A fully coupled model for actuation of higher order modes of Lamb waves

Ren, Baiyang; Lissenden, Cliff J.

doi:10.1063/1.4974577

Cited by 6 publications

(6 citation statements)

References 16 publications

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“…Piezoelectric wafer active sensors (PWAS) are being used extensively for SHM applications and have been shown to withstand exposure to extreme environments [113]. They are non-resonant wide-band devices [114] however they can be used for generation of single Lamb wave modes with careful geometry selection [115]. PWAS are small, inexpensive, and minimally invasive [114], making them potentially suitable for installation on turbine blades and NGVs if a suitable bonding method and piezoelectric material can be found.…”

Section: Measurement Devices For the Generation And Acquisi-mentioning

confidence: 99%

Surface temperature condition monitoring methods for aerospace turbomachinery: exploring the use of ultrasonic guided waves

Yule

Zaghari

Harris

et al. 2021

Meas. Sci. Technol.

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Turbine blades and nozzle guide vanes (NGVs) are operated at extreme temperatures in order to maximise thermal efficiency and power output of an engine. In this paper the suitability of existing temperature monitoring systems for turbine blades and nozzle guide vanes are reviewed. Both offline and online methods are presented and their advantages and disadvantages are examined. The use of offline systems is well established but their online equivalents are difficult to implement because of the limited access to components. There is the need for an improved sensor that is capable of measuring temperature in real time with minimum interference to the operating conditions of the engine, allowing operating temperatures to be increased to the limits of the components and maximising efficiency. Acoustic monitoring techniques are already used for a large number of structural health monitoring applications and have the potential to be adapted for use in temperature monitoring for turbine blades and NGVs. High temperatures severely affect the response of ultrasonic transducers. However, waveguides and buffer rods can be used to distance transducers from extreme conditions, while piezoelectric materials such as Yttrium Calcium Oxyborate single crystals and Aluminum Nitride have been developed for use at high temperatures. A new monitoring approach based on ultrasonic guided waves is introduced in this paper. The geometry of turbine blades and NGVs allows Lamb waves to propagate through their structure, and the presence of numerous cooling holes will produce acoustic reflections that can be utilised for monitoring temperature at a number of locations. The dispersive nature of Lamb waves makes their analysis difficult; however, wave velocity in dispersive regions is particularly sensitive to changes in temperature and could be utilised for monitoring purposes. The proposed method has the potential to provide high resolution and accuracy, fast response times, and the ability to place sensors outside of the gas path. Further research is required to develop a monitoring system based on the use of guided waves in extreme environments.

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Section: Measurement Devices For the Generation And Acquisi-mentioning

confidence: 99%

Surface temperature condition monitoring methods for aerospace turbomachinery: exploring the use of ultrasonic guided waves

Yule

Zaghari

Harris

et al. 2021

Meas. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Piezoelectric Wafer Active Sensors (PWAS) are being used extensively for SHM applications and have been shown to withstand exposure to extreme environments [32]. They are nonresonant wideband devices; however, they can be used for generation of single Lamb wave modes with careful geometry selection [33]. PWAS are small, inexpensive, and minimally invasive [34], making them potentially suitable for installation on NGVs if a suitable bonding method and piezoelectric material can be found.…”

Section: Lamb Wave Mode Targetingmentioning

confidence: 99%

Modelling and Validation of a Guided Acoustic Wave Temperature Monitoring System

Yule

Zaghari

Harris

et al. 2021

Sensors

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The computer modelling of condition monitoring sensors can aide in their development, improve their performance, and allow for the analysis of sensor impact on component operation. This article details the development of a COMSOL model for a guided wave-based temperature monitoring system, with a view to using the technology in the future for the temperature monitoring of nozzle guide vanes, found in the hot section of aeroengines. The model is based on an experimental test system that acts as a method of validation for the model. Piezoelectric wedge transducers were used to excite the S0 Lamb wave mode in an aluminium plate, which was temperature controlled using a hot plate. Time of flight measurements were carried out in MATLAB and used to calculate group velocity. The results were compared to theoretical wave velocities extracted from dispersion curves. The assembly and validation of such a model can aide in the future development of guided wave based sensor systems, and the methods provided can act as a guide for building similar COMSOL models. The results show that the model is in good agreement with the experimental equivalent, which is also in line with theoretical predictions.

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“…The baseline FE model is compared with the room temperature experimental data [23] before performing the sensitivity study. Good agreement with the experimental and model data is obtained at room temperature for the resonant and anti-resonant frequencies as shown in Fig.4.…”

Section: Validation Of Model Data With the Reference Experimental Datamentioning

confidence: 99%

“…Comparison of model data (blue line) and experimental data[23] (black dashed line) for the electrical admittance of PZT-5A at room temperature.…”

mentioning

confidence: 99%

Resonance analysis of a high temperature piezoelectric disc for sensitivity characterization

Bilgunde

Bond

2018

Ultrasonics

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Ultrasonic transducers for high temperature (200 °C+) applications are a key enabling technology for advanced nuclear power systems and in a range of chemical and petro-chemical industries. Design, fabrication and optimization of such transducers using piezoelectric materials remains a challenge. In this work, experimental data-based analysis is performed to investigate the fundamental causal factors for the resonance characteristics of a piezoelectric disc at elevated temperatures. The effect of all ten temperature-dependent piezoelectric constants (ε, ε, d, d, d, s, s, s, s, s) is studied numerically on both the radial and thickness mode resonances of a piezoelectric disc. A sensitivity index is defined to quantify the effect of each of the temperature-dependent coefficients on the resonance modes of the modified lead zirconium titanate disc. The temperature dependence of s showed highest sensitivity towards the thickness resonance mode followed by ε, s, s, s, d, d, s, ε, and d in the decreasing order of the sensitivity index. For radial resonance modes, the temperature dependence of ε showed highest sensitivity index followed by s, s and d coefficient. This numerical study demonstrates that the magnitude of d is not the sole factor that affects the resonance characteristics of the piezoelectric disc at high temperatures. It appears that there exists a complex interplay between various temperature dependent piezoelectric coefficients that causes reduction in the thickness mode resonance frequencies which is found to be agreement in with the experimental data at an elevated temperature.

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A fully coupled model for actuation of higher order modes of Lamb waves

Cited by 6 publications

References 16 publications

Surface temperature condition monitoring methods for aerospace turbomachinery: exploring the use of ultrasonic guided waves

Surface temperature condition monitoring methods for aerospace turbomachinery: exploring the use of ultrasonic guided waves

Modelling and Validation of a Guided Acoustic Wave Temperature Monitoring System

Resonance analysis of a high temperature piezoelectric disc for sensitivity characterization

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