基于完全同步方法的开槽箱梁涡振模型及悬索桥三维涡振研究

Super long span and limit span suspension bridge with steel box girder is low-close-frequency structure, which is sensitive to vortex-induced-vibration (VIV). This kind of forcing, that can produce high vibration levels, occurs at very low reduced velocities concerning low wind speed and high-frequency modes. Vortex-induced force shows high level correlation and nonlinearlity relationship with vortex-induced dispalcement, but force and displacement were not extracted by complete synchronization method in traditional wind tunnel test when investigating vortex shedding phenomena and identifying VIV model parameters. This work will be carried out through wind tunnel test, numerical simulation and theory analysis to investigate VIV of this kind of bridge. Firstly, complete synchronization method of identifying VIV model parameters is built, and then based on the method, vortex shedding force parameters is identified by section model test. Thereafter, a taut strip model of slotted box girder is designed to test spanwise VIV shedding force，and get the vortex induced force correlation function both in vertical and torsional directions．Lastly,considering influence of spanwise vortex shedding force correlation and model shape，the system is deduced to describe spanwise vertical and torsional VIV response of girder by using single degree of freedom models．Achievements in this work will provide evidence for the research of VIV mechanism and control, and has significant theory and engineering value for solving the span augment of suspension bridge.

超大跨度、极限跨度钢箱梁悬索桥属低密频结构，在低折算风速下的涡激振动发生频繁且振幅大，影响行车安全。共振发生时，涡激力与振动位移相关且呈强烈非线性，传统方法在研究涡激振动数学模型时，采用测力、测振非完全同步方法，无法保证力与位移的真实相关关系。项目从风洞试验、数值模拟和理论分析三方面，对该类桥梁进行基于完全同步方法的涡激振动研究：首先将传统的非完全同步方法涡激气动参数识别改进为完全同步方法，据此探讨开槽钢箱梁的合理化涡激力模型及参数识别；其次，采用拉条模型测压风洞试验研究涡激力空间相关性函数，探讨振型、展向距离等因素对竖向和扭转涡激力相关性函数的影响规律；最后，基于二维涡激力模型和涡激力空间相关函数，建立三维空间涡激振动描述方法并进行解析。项目成果可为大跨悬索桥的涡激振动机理研究和涡激振动控制方法研究提供依据，具有理论意义和工程价值。

超大跨度、极限跨度钢箱梁悬索桥属低密频结构，在低折算风速下的涡激振动发生频繁且振幅大，影响行车安全。共振发生时，涡激力与振动位移相关且呈强烈非线性，传统方法在研究涡激振动数学模型时，采用测力、测振非完全同步方法，无法保证力与位移的真实相关关系。项目从风洞试验、数值模拟和理论分析三方面，对该类桥梁进行基于完全同步方法的涡激振动研究：首先通过风洞实验实现了涡激气动参数识别的同步方法，据此探讨钢箱梁的合理化涡激力模型及参数识别；由于涡激气动力参数对风场比较敏感，基于递归图理论对飓风信号非平稳特征定量分析,该方法适用性强且噪声对计算过程的影响较小，采用递归图方法，研究了涡激气动力和涡激振动位移的非平稳定量特征。其次，基于测压风洞试验研究涡激力空间相关性函数，探讨涡激力空间相关性的影响规律；最后，基于二维涡激力模型和涡激力空间相关函数，建立了三维空间涡激振动描述方法并进行解析，基于ANSYS软件，实现了悬索桥三维涡振的数值模拟。项目成果可为大跨悬索桥的涡激振动机理研究和涡激振动控制方法研究提供依据，具有理论意义和工程价值。