Analysis of precision and error of cable force identification of cable-stayed bridge

In this paper, in order to improve the precision of cable force identification of a practical cable-stayed bridge and consider some precision problems of vibration method in surveying the cable force in the engineering application, firstly, three calculation methods for the cable force measurement are analyzed and contrasted; secondly, using the method of finite element numerical simulation and the theory of the error analysis, the effect of both bending rigidity and constraint conditions on simple formula of vibration method is investigated; and the dependence of the precision of cable frequency identification on spectrum resolution, sampling time, and the number of sampling points is studied; Finally, fundamental frequency method, frequency difference method, and peak value method are applied to the cable force calculation of a practical project; and their computational precision and error are contrasted and analyzed. It is observed that it is essential to take into account the effect of every factor on the precision of the cable force identification and make it possible to identify the cable force more accurate by vibration method; and that it simultaneously provides an effective basis for the development of a high-precision equipment.