Method for measuring natural vibration frequency and cable force of inhaul cable in real time

Abstract

The invention discloses a method for measuring the natural vibration frequency and the cable force of an inhaul cable in real time. An acceleration sensor and a magnetic flux sensor are simultaneouslyarranged on an inhaul cable, the acceleration sensor and the magnetic flux sensor are used for calibrating an inhaul cable natural vibration frequency model, a theoretical model between the natural vibration frequency and the induced voltage is constructed, and therefore, the two basic physical quantities of cable force measurement form a one-to-one correspondence relationship. Under the condition that the cable force of the inhaul cable is unknown, calibration of the inhaul cable natural vibration frequency model can be achieved only by applying different loads to the bridge floor. The defect that field calibration, especially field calibration on an in-service bridge, is difficult through a magnetic flux method is overcome. The acceleration sensor only plays a calibration role, the method is essentially based on the measurement principle of a vibration frequency method, and real-time measurement of the natural vibration frequency and the cable force of the inhaul cable is achieved through the magnetic flux sensor. The method has the advantages of good real-time performance, high precision and simple field calibration.

Description

technical field [0001] The invention relates to a technique for measuring the natural frequency and force of a cable, in particular to a method for measuring the natural frequency and force of a cable in real time. Background technique [0002] In recent years, long-span bridges have continued to be built. Cable-stayed bridges and suspension bridges are currently two of the more common types of long-span bridges, and multiple cables are symmetrically installed on them. As the main bearing member of the bridge, the cable force of the cable directly controls the internal force distribution and alignment of the whole bridge. Therefore, in the process of bridge construction and operation, the cable force of each cable must meet the design requirements, otherwise it will seriously affect the safety and stability of the bridge structure. [0003] At present, the methods of cable force measurement in engineering mainly include pressure gauge method, pressure sensor method, vibrati...

AI Technical Summary

Problems solved by technology

Therefore, the magnetic flux method requires pre-calibration of U s The linear relationship between F and F, and in the pre-calibration, the cable force needs to be known. It will be very inconvenient to load the cables step by step on site, especially for in-service bridges. obviously unrealistic

The current common practice is to pre-install the magnetic flux sensor on the cable, and then transport the cable to the site and install it on the bridge after the calibration is completed in the factory. bridge

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