斜拉桥梁－索－阻尼器耦合振动研究

项目名称： 斜拉桥梁－索－阻尼器耦合振动研究

项目编号： No.50808063

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 梁栋

作者单位： 河北工业大学

项目金额： 20万元

中文摘要： 在大跨度斜拉桥的建造过程中，拉索减振是关键技术之一。随着跨度增大，斜拉桥的整体刚度急剧下降，基频降低，其整体频率与拉索的频率已十分接近，极易产生索、梁耦合的大幅振动。因此，索梁耦合振动对拉索阻尼器减振效果的影响是一个非常值得研究的现实工程问题。 本课题进行了理论分析和大量的试验研究，研究成果对大跨度斜拉桥拉索阻尼器的优化设计、运营安全及保证桥梁的使用寿命等方面具有重要意义，同时也丰富了拉索减振领域的研究成果，对类似工程具有指导意义。主要成果包括： 1. 突破了现有拉索阻尼器设计理论中拉索边界条件的限制，建立了更为接近真实情况的拉索阻尼器理论分析模型，分析结果表明：索梁动力耦合程度与拉索阻尼器的减振效果密切相关，耦合程度越大，减振效果降低地越多。建议在斜拉桥的设计过程中，通过调整拉索的物理参数，如自重、索力等，尽量避免索梁耦合振动的发生； 2. 评估了常用的非线性阻尼器在考虑主梁振动情况下的减振效果，指出：根据索梁动力耦合的程度不同，主梁振动会不同程度地削弱非线性阻尼器的减振效果； 3. 斜拉桥上大量的拉索阻尼器会增加斜拉桥的模态阻尼，拉索阻尼器对于斜拉桥的抗震及抗风性能具有正面影响。

中文关键词： 斜拉桥；梁－索－阻尼器耦合振动；阻尼器减振；理论分析；模型试验研究

英文摘要： Cable's vibration mitigation is one of the key works for cable-stayed bridge with long span. As the span increases, the stiffness of cable-stayed bridge reduces dramatically. And the frequencies of whole bridge and cable are very close, so the possibility of coupled vibration between girder and cable increases. The coupled vibration between girder and cable has a high degree of dependency with the dynamic characteristics of cable-stayed bridge, so the effects of girder's vibration on the performance of damper is a very worthy of realistic engineering problems. A detailed study of the effects of girder's vibration on the performance of damper was made through hard work of theoretical analysis and indoor test. The optimal design method of damper got from this project can extend the life of cable. The following results were obtained: 1. The boundary conditions on the cable-related damper design were broke through, and a theoretical analysis model which is closer to the real situation was established. The results show us: the performance of damper is closely related to the degree of coupling vibration between cable and girder. The greater the degree of coupling, the damping effect to reduce more. 2. Based on the energy equivalent method, the performances of 3 different types of nonlinear damper were assessed. The conclusion is: the coupling vibration of cable and girder will weaken the damping effect of nonlinear damping with varying degrees. 3. The effect of numerous cable-related dampers on the dynamic characteristics of whole cable-stayed bridge was made in this project. The results show that the numerous cable dampers have positive effects on seismic and wind resistance of cable-stayed bridge.

英文关键词： cable-stayed bridge; coupling vibration between girder; cable and damper; vibration mitigation; theoretical analysis; model test