Method for Measuring Cable Force of Vibrating Cable Based on Linear Model

Abstract

The invention relates to a stay cable stay force measuring method based on a vibration method using a linear model which belongs to the technical field of construction engineering. The method provided in the invention aims to solve problems of prior art. The problems are illustrated as follows. In the prior art, a stay force measuring method, normally based on the assumption of a specific physical model, is difficult to realize a unified recognition of various stay forces and in different measuring methods, the definition of parameters also varies. It is also difficult to operate to mix different measuring methods for use. All these factors undermine measuring accuracy. The method of the invention is carried out as follows. Tensioning a stay cable with two grades of pulling forces; under each grade of pulling force, using a speed accelerator sensor to measure the speed acceleration signals under the action of environment excitation or people excitation; converting the signals into auto power spectrum patterns; substituting each grade frequency of the two grades of pulling forces and the tensioning force into a linear model; identifying linear model coefficients corresponding to each grade frequency and realize the recognition of model parameters. The recognized linear model and the natural vibration frequency of each grade make it possible to recognize the stay cable stay force. With the method provided in the invention, a relatively-high-accuracy measuring value of stay force can be achieved and the problem of recognizing physical parameters to measure stay force using a traditional vibration method can be avoided, thus making the method reduce the uncertainty of a stay force test.

Description

technical field [0001] The invention relates to a method for measuring the force of a vibrating cable, belonging to the technical field of structural engineering. Background technique [0002] Cable-stayed bridges, suspension bridges and hanger arch bridges all transfer the deck system and vehicle loads to the main force-bearing members through cables, collectively referred to as cable-supported bridges. The cable force vibration method measurement is an important technical means for the inspection and construction monitoring of cable-supported bridges. [0003] Two key problems need to be solved when the cable force test of the vibration method is used: 1) the identification of the natural frequency of the cable, and 2) the determination of the corresponding relationship between the cable force and the natural frequency. Under the conditions of existing measuring instruments and analysis means, the accuracy of measuring frequency can reach 0.005Hz. Therefore, the accuracy...

AI Technical Summary

Problems solved by technology

[0019] The purpose of the present invention is to provide a method for measuring cable force based on a linear model of a vibration method, so as to solve the problem that the cable force test method based on a specific physical model assumption in the prior art is difficult to uniformly identify a variety of cable forces and different measurement methods. Parameter definitions are different, mixed operation is difficult, and problems affecting measurement accuracy

Images