Dynamic response analysis method of cable-stayed bridge under cable broken based on modal updating

Abstract:

In order to consider the influence of the stayed cable breakage process characteristics and the time-varying characteristics of the bridge mode, and reflect the whole process characteristics of the structural dynamic response in the cable breaking accident, this paper proposes a dynamic response analysis method of the cable-stayed bridge under the action of the sudden cable-breaking process model and the structural modal information update strategy. Numerical simulation is mainly used to analyze the dynamic behavior characteristics of bridges under typical cable-stayed bridges and to study the influence of broken cables on the dynamic response characteristics of bridges when broken cables are held. The results show that the modal updating method considering the characteristics of cable breakage process increases the peak dynamic response of the bridge structure by nearly 10% compared to the case without considering it, and the overall response also shows a slight lag phenomenon; When a single main tower cable breaks in different parts, the types and peak positions of the dynamic response of the entire bridges main beam structure are summarized. It was found that when the duration of cable breakage is greater than the basic period of the structure, the dynamic amplification coefficient of the structure changes less and the amplitude approaches 1.0; When the suspension time is 0.011.0 times the basic period of the structure, the dynamic amplification coefficient of the structural response increases to its peak as the suspension time shortens. The research results can provide reference and guidance for the design and post structural evaluation of similar bridge types considering sudden cable breakage.