漂浮体系斜拉桥黏滞阻尼器参数的简化计算

Simplified Calculation of Viscous Damper Parameter for Floatingsystem Cablestayed Bridge XU Yan, TONG Chuan, LI Jianzhong

摘要:

根据漂浮体系斜拉桥的动力响应特点以及近断层速度脉冲型地震动特性，基于结构动力学基本理论，提出了考虑附加黏滞阻尼器的漂浮体系斜拉桥三质点简化动力模型.利用等效阻尼比概念以及能量消耗等效原理，推导得到了速度脉冲型地震动作用下漂浮体系斜拉桥线性及非线性黏滞阻尼器阻尼系数的简化计算公式.最后，通过一座漂浮体系斜拉桥实例，验证了相关公式的正确性.

关键词:斜拉桥; 黏滞阻尼器; 三质点简化动力模型; 速度脉冲; 等效阻尼比

Abstract:

In the light of velocity pulse characteristics of nearfault ground motion and the dominated vibration mode to the dynamic response of floatingsystem cablestayed bridge, a threemass simplified dynamic model was derived and the differential dynamic equation was established. Based on the method of equivalent damping ratio and equivalent linearization of nonlinear viscous dampers, design formulas for determining the damping coefficient of nonlinear viscous dampers of the bridge subjected to nearfault ground motion were deduced. Finally, the accuracy of the proposed design formulas for nonlinear viscous dampers in predicting the damping ratio of the bridge was verified by a real cablestayed bridge.

Key words:cablestayed bridge; viscous damper; threemass simplified dynamic model; velocity pulse; equivalent damping ratio