Measurement of the Bridge Surface Deflections Using Near-Field Amplitude of Secondary Radiators System
| Autor: | Yevhen Poliakov, Viktor Ivanov, Andrii Lebedynskyi, Ruslan Pashchenko, Oleksandr Poliarus |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Surface (mathematics)
Materials science Surface deflection Physics and Astronomy (miscellaneous) business.industry lcsh:T Antenna directivity pattern Field amplitude measurement Near and far field Structural engineering Bridge (interpersonal) lcsh:Technology Amplitude Radiating element Management of Technology and Innovation lcsh:Q Remote measurement business lcsh:Science Engineering (miscellaneous) |
| Zdroj: | Advances in Science, Technology and Engineering Systems, Vol 2, Iss 6, Pp 217-244 (2017) |
| ISSN: | 2415-6698 |
| Popis: | In remote measurements on large-sized objects main focus is on measuring deformations of bridge surfaces and determination of the dynamic amplification factor in particular. The proposed method estimates deflections of entire lower surface of a bridge due to placement of secondary radiators on this surface. Antenna array directivity pattern (ADP) is distorted during deflection of the bridge surface. ADP distortions contain the information about deflections of the individual points of the surface. Minimization of the distance in a functional space with a quadratic metric (the functional) between a distorted measured ADP and theoretical one allows us to determine these deflections. The main problem is measurement of the secondary radiators system ADP in far zone which often cannot be achieved for real bridges in practical situations. Therefore, a new method for determining surface deflections based only on field amplitude measurements in near-field zone of a secondary radiators system is considered in the article. This amplitude of field strength depends on the bridge surface deflection. The modulus of difference between the normalized amplitude distribution of the measured field at the outputs of the receiving array elements, which is created by the radiators system of an unloaded bridge, and the similar amplitude field distribution of a loaded bridge is minimized and deflection of the bridge at the points of the radiating elements placement is calculated. |
| Databáze: | OpenAIRE |
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