A Fiber Bragg Grating Strain Gauge Simultaneously Measuring Reinforcement Temperature and Strain

Abstract

The invention provides an optical fiber grating strain gauge for simultaneously measuring the temperature and strain of steel bars. It utilizes multi-section arc-shaped metal sheets with the same diameter as the steel bar to be measured to connect each other to form the main structure of the sensor. The arc-shaped metal connecting piece with flange and The arc-shaped metal connecting piece forms a cavity, and the two ends of the cavity and the grooved arc-shaped metal connecting piece parallel to the cavity are respectively connected with an arc-shaped metal sheet. Arc-shaped metal middle piece. The first bare fiber grating is fixed in the groove of the arc-shaped metal connecting sheet with grooves to form a fiber grating strain sensor, and the second bare fiber grating is fixed in the groove of the arc-shaped metal intermediate sheet with grooves to form a fiber grating temperature sensor. The temperature measurement value of the fiber grating temperature sensor is used to compensate the strain measurement value of the fiber grating strain sensor, so as to achieve the simultaneous measurement of steel bar strain and temperature. The strain gauge has high precision and small size, and has wide engineering application prospects.

Description

technical field [0001] The invention relates to a steel bar strain and temperature measuring device, in particular to a sensor for simultaneously measuring the steel bar strain and the temperature at a measuring point in a civil engineering reinforced concrete structure. Background technique [0002] Reinforcement strain is one of the main parameters reflecting the stress state of reinforced concrete structures. Whether it is model experiments or actual engineering structure performance monitoring, reinforcement strain is an important content of reinforced concrete structure testing. Traditional steel bar strain gauges are based on the principle of resistance strain sensing or vibrating wire sensing. The test signal is susceptible to electromagnetic interference, the reliability of long-term monitoring results is poor, distributed measurement cannot be realized, the wires are complicated, and the vibrating wire steel bar strain gauge cannot Disadvantages such as dynamic test...

AI Technical Summary

Problems solved by technology

Traditional steel bar strain gauges are based on the principle of resistance strain sensing or vibrating wire sensing. The test signal is susceptible to electromagnetic interference, the reliability of long-term monitoring results is poor, distributed measurement cannot be realized, the wires are complicated, and the vibrating wire steel bar strain gauge cannot Disadvantages such as dynamic testing

When installing the traditional steel bar strain gauge, it is necessary to cut off the steel bar to be measured, and then weld the steel bar strain gauge in the shape of steel bar to the cut-off position of the steel bar to be tested. Due to the protrusion of the welded part, the force transmission state of the joint surface between the steel bar and the concrete changes. As a result, changes in the stress state of the measured steel bars in reinforced concrete structures have disadvantages such as limited accuracy, complicated installation, and great impact on the measured structure.

Therefore, the existing steel bar strain gauges for reinforced concrete structures cannot meet the needs of high precision and long-term monitoring, and there is an urgent need for a steel bar strain gauge with superior performance

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