FBG (fiber bragg grating) stay cable force monitoring sensor based on frequency method, and sensing method

Abstract

The invention relates to an FBG (fiber bragg grating) stay cable force monitoring sensor based on frequency method, and a sensing method. The monitoring sensor employs an FBG acceleration sensor, andthe FBG acceleration sensor consists of a fiber internal engraved optical grating, fiber signal leading-out ports, a cantilever device, and a mass block. The fiber internal engraved optical grating isfixed through the cantilever device, and two ends of the fiber internal engraved optical grating extend to form fiber leading-out lines. The fiber leading-out lines are led out of the fiber signal leading-out ports which are symmetrically disposed at two ends. One end of the cantilever device is fixedly provided with the mass block through a limiting screw. The sensor is installed on the surfaceof a stay cable through a dedicated pedestal and the limiting screw, so as to capture a vibration signal of the stay cable. Moreover, the sensor is provided with dedicated visual application software,and a set of long-term online monitoring system is formed. The sensor is convenient to install, can adapt to a complex environment and the remote signal transmission, and is good in data stability.

Description

technical field [0001] The invention relates to the technical field of force monitoring of flexible cables in civil engineering structures, in particular to a fiber grating type cable force monitoring sensor based on a frequency method. Background technique [0002] The cable is the tension member in the structure, and it is an important part of the long-span space structure, suspension cable structure and cable-stayed structure. Cables are often twisted with high-strength steel wires, which can be divided into steel strands, steel wire bundles and steel wire ropes, and the two ends are fixed with special anchor heads. [0003] After the long-term operation of the structural cable, the state of the cable force needs to be monitored. One is to judge whether the monitored cable force is in a safe working state, and to warn of cable failure caused by overload, cable corrosion, and anchor head corrosion. In order to take timely treatment measures to ensure safety; the second is...

AI Technical Summary

Problems solved by technology

[0004] For the cable force monitoring of structural cables, the traditional method is to install a compressive stress type cable force sensor at the anchorage position during the cable construction period. Once the cable structure is tensioned and constructed, it cannot be installed during the bridge operation period. Or replace it, especially the cable structure that was not considered to be installed during the construction stage, and the anchorage can no longer be removed and the stress type cable force sensor can be installed later.

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