High-durability and long-scale-distance fiber grating sensor and manufacturing method therefor

Abstract

A high-durability and long-scale-distance fiber grating sensor and a manufacturing method therefor, which relate to the technical field of fiber grating sensors. A fiber grating is disposed on the middle segment of a commercial optical fiber. A bushing, a woven fiber jacket layer, and a packaging structure are disposed on the periphery of the commercial optical fiber. The commercial optical fiber and the bushing therebetween are fixed by using fixing points in the bushing. Anchoring segments are disposed between the fixing points in the, bushing and the woven fiber jacket layer. Two ends of the commercial optical fiber are sequentially connected to optical fibers on the anchoring segments and connecting optical fibers. Tail ends of the connecting optical fibers are connected to a transmission cable by using connecting flanges. By using the apparatus and the manufacturing method, the applicability and the durability of application of the fiber grating sensor in the civil traffic engineering field are improved, thereby providing a stable and reliable apparatus for long-time detection and sound monitoring of large engineering structures in the civil traffic engineering field.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of International Patent Application PCT / CN2014 / 072967, filed Mar. 6, 2014, designating the United States of America and published in English as International Patent Publication WO 2015 / 014126 A1 on Feb. 5, 2015, which claims the benefit under Article 8 of the Patent Cooperation Treaty and under 35 U.S.C. §119(e) to Chinese Patent Application Serial No. 201310332548.1, filed Aug. 2, 2013, the disclosure of each of which is hereby incorporated herein in its entirety by this reference.TECHNICAL FIELD[0002]The application relates to the technical field of fiber Bragg grating sensors and as associated manufacturing method.BACKGROUND[0003]As important techniques for improving structural safety, disaster prevention, disaster mitigation, and intelligent management and maintenance in large-scale civil work and traffic engineering, structural health monitoring techniques have received extensive attention. ...

AI Technical Summary

Benefits of technology

[0008]Described is a long gauge fiber Bragg grating (LG-FBG) sensor with high durability and long gauge length and a manufacturing method for the LG-FBG sensors for long-term sensing and health monitoring for large-scale engineering structures in civil work and transportation engineering fields, which can solve the problems of poor stability and durability of conventional FBG sensors in long-term sensing / monitoring in harsh environments, overcome the problems of slippage of fiber core and coating layer and stress concentration on the anchoring segment in the measuring process with LG-FBG sensors, and improve the applicability and durability of LG-FBG sensors in application in the civil work and transportation engineering fields. The LG-FBG sensor is an element for the distributed area sensing system for the large-scale civil work and transportation engineering structures.

Problems solved by technology

Conventional sensors have poor durability and are subject to severe interferences in sensing and data transmission.

Therefore, they are only applicable to short-term and small-scale detection, but are generally unsuitable for long-term real-time monitoring in an embedded state, and cannot meet the requirement for long-term detection and structural health monitoring.

The local sensing and monitoring technique is too “local” to capture the damage.

For global sensing and monitoring techniques, it is so global that the measurements are in a quite poor relation to the damage.

Furthermore, it is difficult if not impossible to employ the conventional sensing and monitoring techniques with a high cost and short sensing gauge for large-scale distributed deployment for large-scale civil work and transportation engineering structures.

For example, for minor damages, if the strain foils or accelerometers are deployed away from the damage, it is difficult for such sensors to monitor damage information.

However, if the strain foils or the like are deployed at some damages, such as cracks, the sensors may be damaged easily.

Moreover, for dynamic measurement, it is difficult for an identification method based upon the global sensor dynamic measurement to reflect the overall performance of the structure and effectively capture the unpredictable damages of the structure.

For large-scale engineering, such as civil work and transportation engineering, sensors used for long-term detecting and structural health monitoring need to have good stability for long-term sensing and durability, but the present conventional sensors can hardly meet the performance requirement of long-term monitoring in civil work and transportation engineering fields.

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