Analysis of Factors Affecting the Accuracy of Moving Force Identification

Abstract

In this study, the influence of the static component in the total force and the effective frequency bandwidth on the accuracy of force identification has been investigated. The acceleration and bending moment responses at different locations of a simply supported beam under different moving forces are numerically measured. The fast Fourier transformation is also introduced to analyze the frequency-domain component of the dynamic responses of the beam. Simulation results show that the dynamic characteristics of the vehicle, such as the frequency of dynamic vehicle load, have significant effect on the proportion of static component in the total vehicle load; the higher the proportion of static component in the total force, the higher the identification accuracy. In addition, the wider the effective frequency bandwidth, the higher the identification accuracy. The numerical results also show that both the proportion of static component in the total force and the effective frequency bandwidth vary with the type and location of measurement. To more accurately identify the moving force, it is necessary to analyze first the static component and frequency characteristics of the measured responses and to select appropriate type and location of measurement.