Cable structure monitoring method based on long gauge optical fiber grating sensors

Abstract

The invention discloses a cable structure monitoring method based on long gauge optical fiber grating sensors. The method comprises the following steps that a healthy monitoring system on the cable structure is laid out by utilizing a cable clamp, wherein the healthy monitoring system is composed of a plurality of long gauge optical fiber grating sensors arranged on the cable structure, and a strain signals monitored by the healthy monitoring system is collected through a signal collection system; an exciting hammer is adopted to hammer the node position where the cable structure lays out the long gauge optical fiber grating sensors; the signal collection system collects an impact signal and a long gauge strain time history in a vibration test; a system array based on an identification algorithm of a subsystem is identified, and multi-layered parameters of the cable structure is further identified; identification on cable force is conducted by utilizing identified frequency, and damage of the cable structure is identified and located according to identified formation and flexibility. According to the cable structure monitoring method based on the optical fiber grating sensors, the optical fiber grating sensors are applied to health monitoring of an inhaul cable, and thus stable and reliable monitoring means and method are provided for long-term monitoring and performance evaluation of the cable structure.

Description

Technical field [0001] The invention belongs to the technical field of structural health monitoring, and particularly relates to a cable structure monitoring method based on a long gauge length fiber grating sensor. Background technique [0002] According to relevant information, as of the end of 2014, the total number of highway bridges in my country has reached 757,100, with 4,257,900 linear meters. Among them, there are 3,404 extra large bridges with a total length of 6,105,400 meters, and 72,979 bridges with a total length of 18,630,100 meters. According to statistics, there are 79,600 dangerous bridges of various types, accounting for approximately 10.5% of the total number of bridges, and the health of the bridges is severe. Long-span bridges often use cable-stayed bridges, suspension bridges, tied-arch bridges and other structural forms, among which the bridge cables are the key component of the long-span bridge structure. For example, in 2001, the suspension cable and b...

AI Technical Summary

Problems solved by technology

[0004] Traditional sensors can only monitor some specific parameters of the structure, but there are always some shortcomings

Common overall sensors include accelerometers, displacement meters, inclinometers, etc. These sensors can be used to monitor and identify macroscopic indicators such as structural acceleration, displacement, rotation angle, and structural frequency, but it is difficult to effectively identify structural damage with macroscopic indicators of structures

Common local sensors include strain gauges, crack gauges, corrosion meters, etc., which can monitor structural details, but they, including the most advanced fiber optic FBG sensors, are point sensors, which are relatively large-scale civil engineering structures. Too localized to capture damage effectively

These point sensors can only show abnormal monitoring values ​​when they are just pasted on the damaged parts of the structure (such as cracks), and in general, the damaged parts of the structure are unknown

Images