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Title |
Development and application of IoT-based contactless ultraosonic system
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Authors |
김지환(Jihwan Kim) ; 홍진영(Jinyoung Hong) ; 김률리(Rrulri Kim) ; 우욱용(Ukyong Woo) ; 최하진(Hajin Choi) |
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DOI |
https://doi.org/10.11112/jksmi.2020.24.3.70 |
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Keywords |
IoT; 비접촉 초음파; 콘크리트; MEMS 센서; 무선 IoT; Contactless ultrasonic; Concrete; MEMS sensor; Wireless |
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Abstract |
The main objective of this research to develop an IoT based wireless contactless ultrasonic system (ICUS) and its application to concrete structure. The developed system consists of 16 mems, 2Mhz digitizer, amplifying circuit, FPGA, and wifi module, enabling to measure leaky surface waves from concrete specimens without physical coupling process and wires. Multi-channel analysis is performed to improve the accuracy of data analysis, and the velocity of leaky surface waves and acoustics are derived. Field inspection of railroad concrete sleepers is conducted to evaluate the performance of the system and to compare the results with conventional ultrasonic pulse velocity (UPV). As a result of the field inspection, UPV was limited to evaluate damages. This is because crack pattern of railroad sleepers is parallel to ultrasonic ray path and accessibility of the railroad at the field is disadvantageous to contact-based UPV. On the other hand, ICUS possibly detect the damages as reduction of dynamic modulus by up to 59% compared to non-damaged specimen.
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