Fabrication and use of fiber grating sensing device and pressure ring using same

Abstract

The invention relates to a device using a fiber grating strain sensor to monitor the force of a structural member, in particular to a fiber grating sensor device and a method for preparing and using a pressure ring using the same. The fiber grating sensing device includes a fiber grating sensor, a package rod and a connecting nut, the middle section of the package rod is provided with a longitudinal groove, the fiber grating sensor is placed in the longitudinal groove, and the two ends of the package rod are provided with Screw thread, the packaged rod is connected to the connecting nut through the threads at both ends, and the two ends of the packaged rod are pre-tensioned to the bare grating through the connecting nut and the pressure ring as the force support, so that the packaged rod and the bare grating are in the best position during the entire service period. under tension. The application also discloses a pressure ring including a fiber grating sensing device, which reduces the influence of bending stress under eccentric loading, reduces measurement errors, improves measurement accuracy, and eliminates measurement errors caused by bending of fiber grating pressure monitoring. At the same time, the production cost is reduced, and the processing time and cost are saved.

Description

technical field [0001] The invention relates to a device for monitoring the force of a structural member by using a strain sensor, in particular to a fiber grating sensing device and a method for preparing and using a pressure ring using the same. Background technique [0002] Stay cables of cable-stayed bridges, suspenders of tied arch bridges, cables of suspension bridges and cableways, anchor rods of geotechnical and slope protection, internal and external prestressed tendons of long-span components, and cable nets in stadiums and net support systems They are the core stress-bearing components of these structures, and the monitoring of their stress state is a necessary means to ensure their safe construction and operation, and is of great significance to their safety assessment, operation management and maintenance, reinforcement decision-making, and disaster prevention and mitigation. At present, the force measuring devices for such components include magnetic flux senso...

AI Technical Summary

Problems solved by technology

The magnetic flux sensor measures the stress of the component by testing the change of the magnetic permeability of the magnetic material. It is a static absolute voltage value and has the following limitations: 1. Because of the mutual interference of the internal coils, the measurement accuracy is not high; 2. When magnetizing the cable A certain response time is required, and the response speed is relatively slow, which leads to the lag of the measurement data; 3. The internal coil and other electronic components are easy to age, which causes the data to drift over time

The frequency meter requires the measured object to vibrate only slightly and has no lateral external thrust, which is easily affected by end constraints such as dampers, so the application is also limited; the resistive strain pressure ring has a long development time and mature production technology, but The application has the following problems: 1. The resistance strain pressure ring has poor durability and short service life, and it is difficult to realize the force monitoring in the structural operation stage; 2. Because it is greatly affected by temperature, it causes a large temperature drift; 3. The resistance strain In the case of eccentric load, the strain pressure ring adopts the method of averaging multiple strain gauges. This method has large errors and low measurement accuracy, and there are great obstacles to the accurate measurement of strain.

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