Structural health monitoring using electro‐mechanical impedance sensors

Abstract

A B S T R A C T This paper reports recent achievements of novel structural health monitoring (SHM) techniques for damage diagnosis for critical members of civil, mechanical and aerospace structures using electro-mechanical impedance sensors. The basic concept of this technique is to use simultaneously both high-frequency structural excitations and responses employing piezoelectric sensors to monitor the local area of a structure for changes in structural impedance that would indicate imminent damage. In this paper, several principal software and hardware issues on these topics are described. A new impedance model is proposed that incorporates the effects of sensor and bonding defects for sensor selfdiagnosis. Temperature effects-free impedance-based damage detection algorithm using effective frequency shifts based on cross-correlation coefficients is presented. In a sense of tailoring wireless sensing technology to the impedance methods, an active sensor node incorporating a miniaturized impedance sensing device, an on-board microcontroller, and a radio frequency (RF) telemetry is introduced. A data compression algorithm is embedded into the on-board chip of the active sensor node to enhance its local data processing-capability. Finally, this paper concludes with a discussion of further studies and future applications.

Real-Time Strength Monitoring for Concrete Structures Using EMI Technique Incorporating with Fuzzy Logic

“…Thus, PZT materials can be used and embedded in concrete to induce and detect wave propagation and vibrations [5,17,18,23]. Through different approaches, the piezoelectric sensors can use to estimate the strength of concrete.…”

“…NDT methods for concrete include the rebound/Schmidt hammer test, ultrasonic wave propagation, and techniques that use PZT (piezoelectric) materials [5,[10][11][12][13][14]. Due to the accuracy of its result, the strength estimation of concrete using EMI has been widely studied [13][14][15][16][17][18][19]. In our work, experiments are conducted on the basis of NDT by analyzing the dynamic response of structures to vibrations using a PZT material sensor and analyzing EMI results [20] with fuzzy logic.…”

Zinc oxide nanoparticle-polymeric thin films for dynamic strain sensing

“…Piezoelectric transducers such as piezo-ceramic lead zirconate titanate (PZT) and poly(vinylidene fluoride) (PVDF) piezo-polymers have been widely adopted for sensing [1], actuation [2], control [3], and energy harvesting [4]. Unique to piezoelectric materials is their inherent ability to simultaneously serve as sensors and actuators.…”

Introducing S-parameters for ultrasound-based structural health monitoring

“…because the interaction between the ultrasonic waves and the structural damage depends on the frequencies and modes of the ultrasound waves, broadband ultrasound inspections have enhanced sensitivity and specificity compared with their narrowband counterparts [9]. another broadband ultrasound inspection scheme is based on monitoring the impedance or admittance of the transducer [10]- [12]. because of the electrical-mechanical coupling of the bonded piezoelectric wafer transducer, structure damage that changes the mechanical impedance of the structure will in turn alter the electrical impedance of the transducer.…”

“…because of the electrical-mechanical coupling of the bonded piezoelectric wafer transducer, structure damage that changes the mechanical impedance of the structure will in turn alter the electrical impedance of the transducer. a shift of the transducer impedance from its original state is therefore presumably due to the structural damage [10]. conventionally, these three types of ultrasound-based sHm technique are implemented separately using different instruments; both the pitch-catch and pulse-echo inspections are performed in the time domain, but the impedances of the transducers are measured in the frequency domain.…”