大跨度斜拉桥拉索参数激励非线性振动及其控制理论与方法

The objective of the proposed study is to investigate on theory and method of mulit-modal parametric vibration and its control of stay cable with severely geometric nonlinearity in cable-stayed bridge with long span. Theoritcal analysis method of the mulit-modal parametric vibratin of the stayed cable with large sag ratio is proposed when considering the effective of chord component force of stay cable’s gravity, and theoritcal model is developed to analysis multi-mode parametric vibration subjected to coupling excitation. The dynamic properties and its parameters influence of the stay cable parametric vibration are studied. The critcal condtions of primary resonance, internal resonance, plane and out-of-plane coupling vibrations are given and unstable region of parametric vibration is also established. The mechanics of the parametric vibration is clearly explained. The passive, active and semi-active vibration controls of the parametric vibration of the stay cable are respectively investigated to explore the dynamic performance, control efficacy and its influence parameters. And the critcal condtion for the unstable region of the parametric vibration of the controled stayed cable. Finally, design approach and theory of passive and intelligent vibration control system with damper's negative stiffness and coupling performance for parametric vibration of stay cables are proposed. The proposed approach is the advancement of effective controll approach for stay cable in cable-stayed bridge, and construction of more economical and safer long-span bridges for public. The outcome will advance the basic science aspects of bridge engineering and have a significant impact on the nation's economic, societal and many other aspects.

项目针对具有强几何非线性特征的大跨度斜拉桥拉索多模态参数振动及其控制理论与方法开展研究。研究考虑重力弦向分力影响的大垂跨比斜拉索多模态参数振动的理论分析方法，建立耦合作用下的斜拉索多模态参数振动的理论分析模型。研究斜拉索参数振动特性及其参数影响规律；给出斜拉索主共振、内共振、面内-面外耦合振动发生条件和参数共振不稳定区域，揭示斜拉索参数振动机理。研究斜拉索多模态参数振动被动、主动和半主动控制动力特性及其参数影响规律，把握受控斜拉索参数振动特点，揭示各参数对斜拉索参数振动控制效果影响规律，建立受控斜拉索参数共振不稳定区临界条件，发展斜拉索参数振动的被动控制和考虑阻尼器负刚度特征及耦合作用的智能控制系统设计方法。本项目研究成果，将形成大跨度桥梁斜拉索参数振动及其控制的理论、方法及其控制系统设计方法，为大跨度桥梁斜拉索减振提供先进有效的方法，具有重要的理论意义和实用价值。

随着跨度超千米级的超大跨斜拉桥的兴建，斜拉桥整体刚度的增加和低阻尼、大柔度超长拉索的工程应用使得斜拉索的振动频率降低、发生振动的模态频率范围变宽，且越来越接近斜拉桥整体的振动频率，从而极易发生斜拉索的大幅值参数振动，对桥梁的安全运营和斜拉索的服役寿命构成巨大威胁。因此不论是在斜拉桥的设计阶段、施工阶段还是正式运营阶段，都应该充分考虑斜拉索参数振动发生的可能性，采取一定的减振控制措施，避免大幅值的斜拉索参数振动的发生。项目针对具有强几何非线性特征的超大跨度斜拉桥拉索多模态参数振动及其控制理论与方法开展研究。建立了考虑重力弦向分力影响的大垂跨比斜拉索多模态参数振动的理论分析方法，和耦合作用下的斜拉索多模态参数振动的理论分析模型。研究了斜拉索参数振动特性及其参数影响规律；给出了斜拉索主共振、内共振、面内-面外耦合振动发生条件和参数共振不稳定区域，揭示斜拉索参数振动机理。采用理论分析与数值计算相结合的方法，分析了超长斜拉索在随机荷载激励下的非线性参数振动特性，为超长斜拉索的参数振动控制提供理论基础。研究了斜拉索多模态参数振动被动控制动力特性及其参数影响规律，把握受控斜拉索参数振动特点，揭示各参数对斜拉索参数振动控制效果影响规律，建立受控斜拉索参数共振不稳定区临界条件，发展斜拉索参数振动的被动控制系统设计方法。本项目研究成果，将形成大跨度桥梁斜拉索参数振动及其控制的理论、方法及其控制系统设计方法，为大跨度桥梁斜拉索减振提供先进有效的方法，具有重要的理论意义和实用价值。