斜拉桥主梁振动对拉索阻尼器减振效果影响的试验研究

Experiment on performance of cable dampers influened by girder vibration for cable-stayed bridges

采用拉索索端阻尼器是大跨度斜拉桥拉索减振的主要措施之一。设计了索、梁和阻尼器组合系统的简化力学模型,研究了组合系统在具备不同力学特性时,主梁振动对拉索附加阻尼器减振效果的影响。分析结果表明,主梁振动降低了拉索附加阻尼器的减振效果;在大跨度斜拉桥拉索的减振设计中,尤其是对于有可能产生索、梁耦合大幅振动的拉索必须考虑主梁参与振动的影响。

One of the most effective measures for vibration mitigation of long stay cables for large span cable stayed bridges is using mechanical damper. In the conventional design theory for cable damper, it is assumed that the cable ends are fixed. However, when the span of cable-stayed bridge becomes large and the structure becomes more flexible, the effect of girder vibration on the cable damper performances have to be considered. In this paper, simplified models with different mechanical performance are used to study the effect of girder vibration. The test results show that the girder vibration reduces the effectiveness of damper. Therefore, it is suggested that the girder vibration should be taken into account in cable damper design for long span cable, especially in the case of cable and girder coupled vibration probably existed.