[This article belongs to Volume - 54, Issue - 01]
Gongcheng Kexue Yu Jishu/Advanced Engineering Science
Journal ID : AES-15-06-2022-222

Title : Transient Response Analysis of Cable-beam Structural System Under Moving Load
JI Jianyi, WANG Ronghui, MA Niujing, YU Xianbin, CHEN Mu,

Abstract :

To verify the applicability of wave theory in studying the free vibration characteristics and impact response of the cable–beam structure, and to preliminarily explore the behaviors of elastic wave propagation through the structure under moving load, the dynamic response function was derived from the transverse vibration differential equation of Timoshenko beam and the longitudinal wave equation of cables. The reverberation-ray matrix was used to obtain the waveform solution of the structural response. Based on the idea of discrete Fourier transform (DFT), the series solution of structural transient response was derived to solve the inverse problem of the traditional reverberation-ray matrix (MRRM). The improved MRRM was verified by experiment and finite element method (FEM). The results showed that at the speed of 30 km/h, the deviation between the theoretical maximum strain and FEM results was 5% and that between theoretical and experimental results was 8%. When the vehicle speed was 40 km/h, the deviation between the theoretical maximum strain and FEM results was 4.0%, which was 9.8% between theoretical and experimental results. Taking the beam-cable system as the research object, the maximum deviation between the first five natural frequencies calculated by improved MRRM and FEM was 0.29%, and the deviation between the first two natural frequencies was 0. The wave response characteristics of the cable-stayed beam under moving load were analyzed and the theoretical results were in good agreement with the FEM results. It could be inferred that the improved MRRM had high reliability in calculating the transient wave response of bridge structure under moving load. Based on the analyses of the frequency domain response, it was found that the flexural waves in the Timoshenko beam under moving load were mainly low-frequency responses whose frequencies were lower than 2 times the fundamental frequency of the structure. Furthermore, the reasonable selection criteria of frequency range were explored in the process of finding the wave response, to further improve the calculation efficiency of MRRM