Crack Detection and Monitoring Using Passive Wireless Sensor

2018

Sensors

Patch antenna sensor is a novel sensor that has great potential in structural health monitoring. The two resonant frequencies of a patch antenna sensor are affected by the crack on its ground plane, which enables it to sense the crack information. This paper presents a detailed characterization of the relationship between the resonant frequencies of a patch antenna sensor and notch-shaped cracks of different parameters, including the length, the orientation, and the center location. After discussing the principle of crack detection using a patch antenna sensor, a parametric study was performed to understand the response of the sensor’s resonant frequencies to various crack configurations. The results show that the crack parameters affect the resonant frequencies in a way that can be represented by the crack’s cutting effect on the sensor’s current flow. Therefore, we introduced a coefficient φ to comprehensively describe this interaction between the crack and the current distribution of the antenna radiation modes. Based on the definition of coefficient φ, an algorithm was proposed for predicting the resonant frequency shifts caused by a random notch-shaped crack and was verified by the experimental measurements. The presented study aims to provide the foundation for the future use of the patch antenna sensor in tracking the propagation of cracks of arbitrary orientation and location in metal structures.

Section: Sensor Design and Simulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characterization of a Patch Antenna Sensor’s Resonant Frequency Response in Identifying the Notch-Shaped Cracks on Metal Structure

Liang

2018

Sensors

“…The patch antenna sensor is a novel sensor used for SHM which can measure the strain and crack of metal structures wirelessly and passively [2]. Deshmukn and Huang first applied patch antennas to the identification of fatigue cracks in metal structures [3]. Subsequently, Yi, Liu and Ke et al [4][5][6] also investigated the crack test results of patch antennas, but the wired connection was mainly used.…”

Section: Introductionmentioning

confidence: 99%

Method of Monitoring Cracks in a Metal Structure Based on Dual-Chip RFID Antenna Sensor

The 6th International Electronic Conference on Sensors and Applications

Yu²,

Zhou

et al. 2019

The microstrip patch antenna sensor is a novel sensor used for structural health monitoring which can measure a metal structure’s crack defects in a wireless manner. However, it is difficult to identify the reflected signal from the signal of an antenna sensor. The radio-frequency identification (RFID) antenna sensor, which combines RFID technology and the microstrip patch antenna sensor, can solve the measurement problems that are difficult to the conventional wireless testing technologies. In this study, a dual-chip RFID antenna sensor was designed. The influence of the wireless testing method on the monitoring results of crack defects was investigated by tests, including the wireless tests of resonant frequency and the crack sensitivity tests. The tests results revealed that the antenna sensor had good wireless testing performance with regard to the metal structure’s crack defects. Additionally, the maximum of wireless identification distance reached 1.96 m.

“…Referring to studies of crack detection using antenna sensors, Deshmukh et al [ 13 ] first proposed a surface crack detection method for use on metallic surfaces that used a rectangular microstrip patch antenna. Their results indicated that the resonant frequency of the antenna decreased with increasing crack length.…”

Section: Introductionmentioning

confidence: 99%

“…In the method of making cracks on specimens, Liu et al [ 18 ] made straight cracks of 0.5 mm width parallel to the length direction of the patch on the central line of the floor. Deshmukh et al [ 13 ] designed and machined a compact tension (CT) specimen according to American Society for Testing and Materials (ASTM) standards (E647-00). A small groove is fabricated at the edge of the floor, and a nearly straight-line crack is produced by fatigue test.…”

Section: Introductionmentioning

confidence: 99%

Crack Monitoring Method for an FRP-Strengthened Steel Structure Based on an Antenna Sensor

Chen

et al. 2017

Sensors

Fiber-reinforced polymer (FRP) has been increasingly applied to steel structures for structural strengthening or crack repair, given its high strength-to-weight ratio and high stiffness-to-weight ratio. Cracks in steel structures are the dominant hidden threats to structural safety. However, it is difficult to monitor structural cracks under FRP coverage and there is little related research. In this paper, a crack monitoring method for an FRP-strengthened steel structure deploying a microstrip antenna sensor is presented. A theoretical model of the dual-substrate antenna sensor with FRP is established and the sensitivity of crack monitoring is studied. The effects of the weak conductivity of carbon fiber reinforced polymers (CFRPs) on the performance of crack monitoring are analyzed via contrast experiments. The effects of FRP thickness on the performance of the antenna sensor are studied. The influence of structural strain on crack detection coupling is studied through strain–crack coupling experiments. The results indicate that the antenna sensor can detect cracks in steel structures covered by FRP (including CFRP). FRP thickness affects the antenna sensor’s performance significantly, while the effects of strain can be ignored. The results provide a new approach for crack monitoring of FRP-strengthened steel structures with extensive application prospects.