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Ultrasonic Lateral Displacement Sensor for Health Monitoring in Seismically Isolated Buildings.

Matsuya I, Matsumoto F, Ihara I - Sensors (Basel) (2015)

Bottom Line: The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side.In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced.When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka 940-2188, Niigata, Japan. matsuya@mech.nagaokaut.ac.jp.

ABSTRACT
An ultrasonic lateral displacement sensor utilizing air-coupled ultrasound transducers is proposed. The normally-distributed far field of an ultrasound transducer in a lateral direction is taken advantage of for measuring lateral displacement. The measurement system is composed of several air-coupled ultrasound transducers as a receiver and several transmitters. The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side. In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced. The difference between the corrected lateral displacement and the reference displacement is estimated to be 0.2 mm at maximum for the two transmitters system. A good responsiveness is demonstrated by conducting a dynamic response experiment. When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm. In both cases, the fluctuations to the measurement ranges show less than 1%. These results indicate that the developed sensor system is useful for measuring relative lateral displacement of a seismically isolated building in the field of structural health monitoring.

No MeSH data available.


Related in: MedlinePlus

Measuring lateral displacement over a wide range. (a) The ultrasound intensity distribution obtained from five transmitters; (b) The corrected lateral displacement.
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sensors-15-17000-f011: Measuring lateral displacement over a wide range. (a) The ultrasound intensity distribution obtained from five transmitters; (b) The corrected lateral displacement.

Mentions: Figure 11 shows the experimental results for the measurement of lateral displacement over a wide range using several ultrasound transmitters. Figure 11a shows the ultrasound intensity distributions obtained from five transmitters. Figure 11b shows the corrected lateral displacement. The open circles show the corrected lateral displacement. The solid line shows the reference displacement. The corrected lateral displacement agrees well with the reference within a 0.70 mm fluctuation. Because the fluctuation rate for the 120 mm range is found to be 0.58%, it is verified that this system has sufficient accuracy for large displacement regions. In addition, this result indicates that the measurement range is easily extended using several air-coupled ultrasound transducers. As mentioned above, the maximum lateral displacement of the isolated layer varies case-by-case according to the damping ratio of the isolator. Therefore, it is important for this sensor to be able to extend its measurement range without limitation when installing it in seismically isolated buildings.


Ultrasonic Lateral Displacement Sensor for Health Monitoring in Seismically Isolated Buildings.

Matsuya I, Matsumoto F, Ihara I - Sensors (Basel) (2015)

Measuring lateral displacement over a wide range. (a) The ultrasound intensity distribution obtained from five transmitters; (b) The corrected lateral displacement.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541918&req=5

sensors-15-17000-f011: Measuring lateral displacement over a wide range. (a) The ultrasound intensity distribution obtained from five transmitters; (b) The corrected lateral displacement.
Mentions: Figure 11 shows the experimental results for the measurement of lateral displacement over a wide range using several ultrasound transmitters. Figure 11a shows the ultrasound intensity distributions obtained from five transmitters. Figure 11b shows the corrected lateral displacement. The open circles show the corrected lateral displacement. The solid line shows the reference displacement. The corrected lateral displacement agrees well with the reference within a 0.70 mm fluctuation. Because the fluctuation rate for the 120 mm range is found to be 0.58%, it is verified that this system has sufficient accuracy for large displacement regions. In addition, this result indicates that the measurement range is easily extended using several air-coupled ultrasound transducers. As mentioned above, the maximum lateral displacement of the isolated layer varies case-by-case according to the damping ratio of the isolator. Therefore, it is important for this sensor to be able to extend its measurement range without limitation when installing it in seismically isolated buildings.

Bottom Line: The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side.In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced.When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka 940-2188, Niigata, Japan. matsuya@mech.nagaokaut.ac.jp.

ABSTRACT
An ultrasonic lateral displacement sensor utilizing air-coupled ultrasound transducers is proposed. The normally-distributed far field of an ultrasound transducer in a lateral direction is taken advantage of for measuring lateral displacement. The measurement system is composed of several air-coupled ultrasound transducers as a receiver and several transmitters. The transmitters are immobilized at a fixed point, whereas the receiver set-up is separately arranged on the opposite side. In order to improve measurement accuracy, a correction method that utilizes polynomial approximation is introduced. The difference between the corrected lateral displacement and the reference displacement is estimated to be 0.2 mm at maximum for the two transmitters system. A good responsiveness is demonstrated by conducting a dynamic response experiment. When five transmitters are arranged, their measurement range is easily extended up to ±60 mm with an accuracy of 0.7 mm. In both cases, the fluctuations to the measurement ranges show less than 1%. These results indicate that the developed sensor system is useful for measuring relative lateral displacement of a seismically isolated building in the field of structural health monitoring.

No MeSH data available.


Related in: MedlinePlus