风-浪-流耦合作用下大跨桥梁多方向宽频域TMD减振研究

大跨桥梁作为沿海城市重要基础设施面临着风浪流多灾害的严峻处境，而现有大跨桥梁减振装备多局限于单一动力灾害抑制，其综合减灾能力欠缺。本项目针对风浪流多场耦合特征及大跨桥梁在风浪流耦合作用下振动特性，研发一种适用于大跨桥梁风浪流多灾害抑制的多方向宽频域调谐质量阻尼器（TMD）。首先对该TMD进行性能试验和力学模型研究，获得滚动阻尼单元、可调刚度单元及TMD整机的各项性能，揭示TMD多方向宽频域减振机制，建立其在风浪流多灾害抑制中的力学模型。其次进行TMD受控结构动力试验，验证TMD多方向宽频域减振效果及模型准确性。最后采用Copula函数、随机谱理论和边界元法仿真风浪流耦合力，采用子结构法建立大跨桥梁-TMD耦合降阶减振系统，通过数值仿真进行风浪流耦合作用下大跨桥梁TMD减振分析，并基于提出的多灾害抑制失效概率进行TMD优化设计。该项目对于提升沿海大跨桥梁综合抗灾减灾能力具有重要意义。

The long-span bridge as the civil infrastructure of coastal cities faces the severe challenge from the wind-wave-current (WWC) multi-hazard scenarios, but existing vibration-reduction equipments for the long-span bridge are mostly aimed at a single dynamic hazard, and their comprehensive hazard-reduction capability is not strong. The purpose of the project is to develop a multi-directional wide-bandwidth tuned mass damper (MW-TMD) for the WWC multi-hazard mitigation, by considering the WWC coupling characteristics and complex dynamic behaviors of the long-span bridge subjected to the WWC coupling load. Through the research on performance tests and mechanics model of the MW-TMD, the various properties of the rolling damping element, adjustable stiffness element, and the whole machine of the MW-TMD will be obtained, the multi-directional wide-bandwidth damping mechanism of the MW-TMD will be revealed, the mechanics model of the MW-TMD in the WWC multi-hazard mitigation will be established. Through the research on dynamic tests of the structure equipped with the MW-TMD, the multi-directional wide-bandwidth damping effect of the MW-TMD and the accuracy of the mechanics model will be verified. The WWC coupling load acting on the long-span bridge will be simulated using the Copula function, random spectrum theory, and boundary element method. The long-span bridge and MW-TMD coupled reduced-order system will be established using the substructure method. Based on the above, the damping effect of the MW-TMD for the long-span bridge subjected to the WWC coupling load will be evaluated through numerical simulations. The optimal design of the MW-TMD will be performed according to the proposed probability of failure for the WWC multi-hazard mitigation. This project has great significance for improving the comprehensive resistance of long-span bridges in coastal cities against the WWC multi-hazard scenarios.