Transducers NDT & SHM
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Piezo transducers for tank monitoring – TWI – Sept 2005
19 June 2023
Detecting microscopic structural vibrations for monitoring storage tanks with piezoelectric transducers.
Piezo-composite patches applied to the detection of defects using lamb wave focusing
19 June 2023
Ultrasonic-based SHM (Structural Health Monitoring) applications usually rely on the use of piezo-electric patches to emit and receive ultrasonic surface acoustic waves. The principle is to study the propagation of the waves through a structure to assess its health. Because of the elevated number of echoes and possible modes of propagation of the acoustic waves within the structure, those applications suffer from a burden of signal processing. This paper presents a composite piezo-electric patch and its electronics that were designed and successfully tested for reducing the complexity of the SHM detection schemes.
Piezo-composite transducer for mode and direction selectivity of Lamb waves
19 June 2023
Ultrasonic-based SHM (Structural Health Monitoring) applications commonly rely on the use of piezo-electric patches to emit and receive ultrasonic waves. The objective is to study the propagation of the waves through a structure to assess its structural integrity. Because of the elevated number of echoes and possible modes of propagation of the waves within the structure, those applications suffer from a burden of signal processing. This paper presents a composite piezo-electric patch that was designed and successfully tested for reducing the complexity of the SHM detection schemes by selecting the mode and direction of the Lamb waves received. The piezo-composite is composed of a row of eight independent ceramic pillars separated with polymer, so it is a 1-D matrix of independent piezo-patches. Used with adequate electronics and signal processing, it was shown that it allowed selecting the direction and the mode of the Lamb waves.
Progress In Magnetostrictive Sonar Transducers
19 June 2023
Continous interest from the French Navy (DRET and CERDSM) has permitted significant improvements to magnetostrictive transducers in order to produce low-frequency high-power sonar sources. These improvements can be appreciated by looking at three transducers.
Capteur électromagnétique effort et applications
19 June 2023
This article deals with a stress sensor for cables which has been designed, built and test. it is based on a special magnetostrictive effect of ferromagnetic materials as high elastic limit steels used for bridge cables or prestressed concrete.
Robustness of SHM techniques based on lamb waves
19 June 2023
Required improvements of piezoelectric elements actuation and measurement system efficiency and robustness are introduced as a critical feature for structural health monitoring (SHM) applications. An electronic module (Lamb wave detection system: LWDS) allowing to use each piezoelectric element in an array either in emission or reception mode is presented. The high commutation rate between these two states, for each transducer separately, is a key enhancement for SHM methods. The robustness of the sensor integration is also studied considering the patches size and bonding method. Coupled dispersion curve are introduced Comparison of FEM simulation and experiments of the piezo-electric coupling are presented. This work takes part of the H2020 REMAP project about adaptive aircraft maintenance planning.
