Analysis of Piezoelectric Diaphragms in Impedance-Based Damage Detection in Large Structures

Budoya, Danilo Ecidir; Castro, Bruno; Campeiro, Leandro Melo; Silveira, Ricardo da; Freitas, Everaldo de; Baptista, Fabrício Guimarães

doi:10.3390/ecsa-4-04896

Cited by 12 publications

(10 citation statements)

References 15 publications

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“…For greater changes of capacitance CL > 15 pF, the frequency change * is a lot smaller. * ( ) = 1 In order to calculate the influence of the series capacitance C L (Figure 3) on the series resonance frequency f s , the crystal resistance R 1 (Equation (4)) is neglected (R 1 = 0), so that the series impedance is obtained for the series quartz coupling and the series capacitance [6,18,23,24].…”

Section: Load Capacitance Influence On Resonancementioning

confidence: 99%

Detection Principles of Temperature Compensated Oscillators with Reactance Influence on Piezoelectric Resonator

Matko

Milanovič

2020

Sensors

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This review presents various ways of detection of different physical quantities based on the frequency change of oscillators using piezoelectric crystals. These are influenced by the reactance changes modifying their electrical characteristics. Reactance in series, in parallel, or a combination of reactances can impact the electrical crystal substitute model by influencing its resonant oscillation frequency. In this way, various physical quantities near resonance can be detected with great sensitivity through a small change of capacitance or inductance. A piezoelectric crystal impedance circle and the mode of frequency changing around the resonant frequency change are shown. This review also presents the influence of reactance on the piezoelectric crystal, the way in which the capacitance lost among the crystal's electrodes is compensated, and how the mode of oscillators' output frequency is converted to lower frequency range (1-100 kHz). Finally, the review also explains the temperature-frequency compensation of the crystals' characteristics in oscillators that use temperature-frequency pair of crystals and the procedure of the compensation of crystals own temperature characteristics based on the method switching between the active and reference reactance. For the latter, the experimental results of the oscillator's output frequency stability (f out = ±0.002 ppm) at dynamical change of environment temperature (0-50 • C) are shown.

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Section: Load Capacitance Influence On Resonancementioning

confidence: 99%

Detection Principles of Temperature Compensated Oscillators with Reactance Influence on Piezoelectric Resonator

Matko

Milanovič

2020

Sensors

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“…The specific transducers used in this study were piezoelectric diaphragms, which have similar characteristics to conventional PZT ceramics [9,10]. The buzzer diaphragms each have a circular brass plate whose dimensions are 20 mm × 0.2 mm that houses a circular piezoelectric ceramic with the dimensions 14 mm × 0.42 mm, which is coated by a metallic film, as shown in Figure 1.…”

Section: Piezoelectric Sensors: Reviewmentioning

confidence: 99%

Study of a Low-Cost Piezoelectric Sensor for Three Phase Induction Motor Load Estimation

Lucas

Castro

Rocha

et al. 2018

5th International Electronic Conference on Sensors and Applications

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Due the complexity of control and automation networks in modern industries, sensor-based systems stand out as effective approaches for failure detection in electrical and mechanical machines. This kind of intervention has a high operational value in industrial scenarios, once it can avoid corrective maintenance stops, i.e., before the failure reaches a high level of severity and compromises the machine. Consequently, the development of sensors applied to non-destructive techniques (NDT) for failure monitoring in electrical machines has become a recurrent theme in recent studies. In this context, this paper investigates the application of low-cost piezoelectric sensors for vibration analysis, which is an NDT that has already proved to be efficient for the detection of many structural anomalies in induction motors. Further, the proposed work presents a low-cost alternative approach for expensive commercial sensors, which will make this NDT more attractive for industrial applications. To describe the piezoelectric sensor frequency response, a pencil lead break (PLB) test was performed. After this validation, the Root Mean Square (RMS) value from the voltage samples obtained in the test bench was used as a signal processing method. A comparison between the results for different levels of mechanical load attached to the machine shaft indicated not only the successful performance of the low-cost sensors for load estimation purposes, but also showed that oversized motors may present higher vibration levels in some components that could cause mechanical wearing.

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“…For example, damage in metallic materials generates acoustic waves between 20 and 500 kHz, which is easily detectable by this kind of sensor. The transducers used in this work were the piezoelectric diaphragms, which have similar characteristics to conventional lead zirconate titanate (PZT) ceramics [11,12]. The piezoelectric diaphragms consist of a circular brass plate, with dimensions of 35 × 0.2 mm, and a circular piezoelectric ceramic, with dimensions of 23 × 0.22 mm and an attenuation of 3 dB at 225 kHz [9].…”

Section: Piezoelectric Transducers and Ae Damage Detectionmentioning

confidence: 99%

Structural Damage Location by Low-Cost Piezoelectric Transducer and Advanced Signal Processing Techniques

Castro

Baptista

Alves

et al. 2018

5th International Electronic Conference on Sensors and Applications

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The development of new low-cost transducers and systems has been extensively aimed at in both industry and academia to promote a correct failure diagnosis in aerospace, naval, and civil structures. In this context, structural health monitoring (SHM) engineering is focused on promoting human safety and a reduction in the maintenance costs of these components. Traditionally, SHM aims to detect structural damages at the initial stage, before it reaches a critical level of severity. Numerous approaches for damage identification and location have been proposed in the literature. One of the most common damage location techniques is based on acoustic waves triangulation, which stands out as an effective approach. This method uses a piezoelectric transducer as a sensor to capture acoustic waves emitted by cracks or other damage. Basically, the damage location is defined by calculating the difference in the time of arrival (TOA) of the signals. Although it may be simple, the detection of TOA requires complex statistical and signal processing techniques. Based on this issue, this work proposes the evaluation of a low-cost piezoelectric transducer to determine damage location in metallic structures by comparing two methodologies of TOA identification, the Hinkley criterion and the statistical Akaike criterion. The tests were conducted on an aluminum beam in which two piezoelectric transducers were attached at each end. The damage was simulated by pencil lead break (PLB) test applied at four different points of the specimen and the acoustic signals emitted by the damage were acquired and processed by Hinkley and Akaike criteria. The results indicate that, although both signal processing methodologies were able to determine the damage location, Akaike presented higher precision when compared to Hinkley approach. Moreover, the experimental results indicated that the low-cost piezoelectric sensors have a great potential to be applied in the location of structural failures.

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Analysis of Piezoelectric Diaphragms in Impedance-Based Damage Detection in Large Structures

Cited by 12 publications

References 15 publications

Detection Principles of Temperature Compensated Oscillators with Reactance Influence on Piezoelectric Resonator

Detection Principles of Temperature Compensated Oscillators with Reactance Influence on Piezoelectric Resonator

Study of a Low-Cost Piezoelectric Sensor for Three Phase Induction Motor Load Estimation

Structural Damage Location by Low-Cost Piezoelectric Transducer and Advanced Signal Processing Techniques

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