Temperature compensation type optical fiber intelligent gasket

Abstract

The invention discloses a temperature compensation type optical fiber intelligent gasket, and belongs to the technical field of monitoring. The gasket is mainly composed of a gasket base and a gasket upper cover. A through hole is formed in the middle of the gasket base, and a groove surrounds the periphery of the through hole; positioning steps are arranged on the periphery of the groove; the gasket upper cover is of a structure with a boss in the circumferential direction and a through hole in the center. A contact is arranged on the gasket upper cover; after the gasket base and the gasket upper cover are combined, it needs to be guaranteed that the boss of the gasket upper cover does not make contact with the step of the gasket base. Based on the fiber bragg grating strain measurement principle and the temperature compensation principle, stress borne by the bolt is converted into deformation of the elastic strain ring to generate strain through structural improvement, so that the wavelength of the fiber bragg grating sensor is changed, meanwhile, the temperature sensor carries out temperature compensation, and the stress state of the bolt is monitored in real time. The device can compensate the influence caused by external temperature change, and has the advantages of high precision, good sealing performance and high practicability.

Description

technical field [0001] The invention belongs to the technical field of monitoring, and in particular relates to a temperature-compensated optical fiber intelligent gasket for monitoring the stressed state of bolts. Background technique [0002] Bolted connections are widely used in key load-bearing structures such as civil transportation, large buildings, aerospace, hydropower and wind power. If the pretightening force of the bolted connection is too large, the bolts will fail, while if it is too small, the bolts will loosen. In the long-term working process, affected by factors such as vibration and force load, the bolts will become loose and deformed, which will damage the structure. Or the product brings great safety hazards, so monitoring the stress state of key bolts has far-reaching significance in engineering. [0003] However, due to the particularity of bolted connections, it is difficult to detect bolts by applying external monitoring means. At present, the optim...

AI Technical Summary

Problems solved by technology

If the pretightening force of the bolt connection is too large, the bolt will fail, while if it is too small, it will cause the bolt to loosen. In the long-term working process, affected by factors such as vibration and force load, the bolt will become loose and deformed, which will damage the structure. Or the product brings great safety hazards, so monitoring the stress state of key bolts has far-reaching significance in engineering

[0003] However, due to the particularity of the bolted connection, it is difficult to detect the bolts by applying monitoring means externally

At present, the optimal detection method is to measure the change of preload force by sensing the structural strain of bolts or gaskets, but in actual use scenarios such as large steel structures, aerospace and other fields, the temperature environment of gaskets will change greatly, and The optical fiber sensor will still produce wavelength changes after sensing temperature changes, which will interfere with the test results. The existing optical fiber smart spacers cannot perform temperature compensation, resulting in low measurement accuracy.

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