台风过程下大跨度悬索桥颤振自适应翼板气动控制理论研究

The traditional passive aerodynamic control is becoming difficult to meet the flutter safety requirements of super long-span suspension bridges, and the emerging active aerodynamic control research based on active winglet is still at a preliminary stage, lacking of theory and verification to consider the typhoon’s threat during the service period: adaptive control theory applicable to the typhoon process has not been established to counter the typhoon’s varying wind speed and strong turbulence characteristics, and aerodynamic control method based on interference effect has not been established to counter the coupling field between the main girder and winglet..This project intends to study the flow-interference mechanism between the winglet and the deck in the transformation process from active control surface to active winglet, and to guide the establishment of precise control model by clarifying the aerodynamic control principle under strong wind field coupling; Then, in-time system identification and dynamic parameters modification will be introduced to handle the typhoon’s varying wind speed and strong turbulence characteristics, to establish adaptive flutter control theory applicable to the typhoon process; Finally, the control theory will be verified and corrected based on perspectives of effectiveness and robustness, through wind tunnel tests with typhoon process simulated by multi-fan..This project will focus on solving key scientific problems such as the wing's best posture regulation mechanism under varying wind speed, the robust control expression of typhoon’s wind spectrum, and the flow field interference law of the deck-winglet system, to provide methods and technical reserves for flutter prevention of super long-span suspension bridges.

传统被动气动控制逐渐难以满足超大跨度悬索桥颤振安全储备需求，而基于主动翼板的新兴主动气动控制研究尚处于初步阶段，缺少考虑服役期间台风威胁的理论方法和试验验证：尚未针对台风变风速、强湍流特性建立适用于台风全过程的自适应控制理论，也未针对主梁和翼板之间的流场耦合建立基于干扰效应的气动控制方法。.本项目拟通过计算流体动力学(CFD)方法分析从主动控制面向主动风嘴转变过程中翼板与主梁之间的流场干扰机制，阐明风场强耦合情况下的气动控制原理，指导精细化控制模型的建立；通过实时系统辨识和动态参数调整应对台风变风速、强湍流的特性，建立适应台风过程的自适应颤振控制算法。最后，通过多风扇主动风洞试验模拟台风过程，从有效性和鲁棒性角度对控制理论进行检验和修正。.本项目拟着重解决翼板最佳姿态的变风速调控机制、台风风谱的鲁棒控制表达原理、主梁翼板系统的流场干扰规律等关键科学问题，为超大跨度悬索桥颤振设防提供方法和技术储备。

超大跨度桥梁颤振稳定性差，需要引入颤振控制措施以保证结构的安全。新型主动翼板可以突破传统外形优化措施的控制极限，已成功实现了均匀流和平板主梁这类理想情况下的颤振控制。但是，实际钝体主梁会与翼板产生复杂的气动干涉，且超大跨度桥往往处于台风影响区。因此，项目研究了钝体主梁在翼板控制下的气动特性和控制方法，并与理想流线型假定进行了对比，分析了不同风攻角和折减风速下两者的异同。提出了适用于钝体主梁的主动翼板控制方法。为研究气动干扰对颤振控制的影响，项目建立了“分布式气动特性分析方法”数学分析方法，能够直观、快捷地展示气动控制的具体机理。利用“分布式气动特性分析方法”对风洞试验中较难定量分析的气动干扰问题进行了详细分析。对于台风湍流下的主动控制问题，项目构建了三维台风风场模型和随机路径模拟方法，获取了大量的台风风速样本数据，建立了不同重现期目标的极值风速灾害曲线。针对台风进行主动控制试验探究控制参数对桥梁颤振性能的影响规律，给出了有效和无效的控制范围，对理论分析和数值模拟结果进行了验证。本项目的研究成果将为超大跨度悬索桥颤振设防提供方法和技术储备。