Analytical Study on the Dynamic Characteristics of Cable Networks
Bridge stay cables are vulnerable to dynamic excitations by wind. There are different countermeasures to suppress unfavorable bridge stay cable vibrations and one of the effective countermeasures is to connect stay cables by cross-ties to form a cable network. However, the dynamic behaviour of a cable network is not clearly understood and most of the current designs are based on physical tests and numerical simulations. In this thesis, an effort has been made to understand the in-plane free vibration of a cable network. Three analytical models have been developed to investigate the in-plane free vibration of a basic cable network with a rigid transverse cross-tie, a general cable network with a single line of rigid transverse cross-ties, and a basic cable network with a flexible transverse cross-tie. The key system parameters of a cable network have been identified, which include the segment ratio, the frequency ratio, the mass-tension ratio, the length ratio, the cross-tie flexibility parameter, and the total number of interconnected cables. Extensive parametric study has been conducted to evaluate the role of each parameter in affecting the performance of a cable network. All the analytical model results are verified by numerical simulations using the Finite Element software ABAQUS 6.9.