Parametric optimization of viscous damper for large-span cable-stayed bridge based on vulnerability

Parametric design of viscous damper for long-span cable-stayed bridge is usually based on performance optimization of a single component under a specific seismic wave without considering effects of randomness of ground motions and relative damage among components. Here, aiming at the above problems, a parametric optimization method based on vulnerability and response surface was proposed. Taking a large-span cable-stayed bridge as an example, its nonlinear dynamic model was established using the software OpenSees, and its aseismic performance under different viscous damper parameters was evaluated based on the vulnerability analysis theory. Nonlinear function relations among damper parameters and vulnerability were fitted using response surface, and parametric optimization was performed with the target of minimizing system vulnerability and reasonable damage path. The results showed that when the velocity index is constant, the aseismic performance of each support monotonically increases with increase in damping coefficient, while aseismic performances of bridge towers and stay cables firstly increase and then decrease, aseismic performances of transition piers and auxiliary piers change very little and are basically not affected by damper parameters; the optimal parameters of viscous damper for cable-stayed bridge are the comprehensively optimal results of aseismic performances of bridge towers and supports; the system' s aseismic performance may be better if its parameters are obtained from the unoptimized components' damage path, but this damage path is not reasonable, the actual aseismic behavior of cable-stayed bridge can be overestimated. © 2023 Chinese Vibration Engineering Society. All rights reserved.