【作者】 刘杰；

【导师】 杨吉新；

【作者基本信息】 武汉理工大学 ， 桥梁与隧道工程， 2020， 博士

【摘要】 大跨度索结构跨越体系在石油、天然气的管道输送工程中担任不可或缺的角色,由于缆索结构长期暴露于空气中,受温度湿度变化等的影响,缆索易出现锈蚀情况,严重时会发生断索事故。碳纤维索具有高强轻质、耐腐蚀、耐高温等优良的物理化学性能,可有效地解决传统钢索面临的困扰,然而碳纤维材料在实际桥梁工程中的应用较少。采用轻质的碳纤维索代替传统钢索,将使得全桥结构更加轻柔,其抗风抗震等动力性能的变化尤未可知。为解决上述问题,本文以一实际工程为背景,对采用碳纤维材料作为索构件的大跨径斜拉-悬索管桥的动力性能展开分析,主要研究内容及结论如下:(1)依托魏荆线汉江跨越管桥换索工程项目,分析斜拉-悬索管桥和普通公路桥梁的区别,总结自身特点。通过轴向等强度原则,将管桥主缆、斜拉索由传统钢材替换为碳纤维材料,并对钢索与碳纤维索性能进行对比分析。(2)选取Davenport水平脉动风谱密度函数,基于线性相位滤波器法中的自回归模型,通过Matlab仿真汉江跨越管桥桥位处三维脉动风场,提取脉动风场湍流参数,作为拉索风致振动研究的边界条件。通过Workbench工作平台,实现风场与拉索的单向流固耦合作用,计算碳纤维索与钢索风致振动响应异同,分析碳纤维索换索方案对桥梁气动特性的改变。结果表明,采用碳纤维索作为拉索材料会增加拉索变形,也会增大拉索应力;顺风向碳纤维索风振响应位移相比传统钢索更大,但其随时间衰减较快。(3)结合斜拉-悬索管桥受力特点,建立桥塔-拉索-主梁耦合参数振动模型,选用Matlab工具进行数值计算;从动力特征与振幅两方面对比研究碳纤维索与钢索参数振动性能,分析各影响参数如桥面位移、索力、桥塔刚度、拉索阻尼等对于结构参数振动的影响;增设粘滞阻尼器,建立阻尼器减振模型,对比分析两种材料拉索的振动控制效果。结果表明:钢索换为碳纤维索后,其主共振振幅变大,次谐波共振减小,总体上拉索振幅变大,参数振动性能不利;增设粘滞阻尼器进行被动控制后,碳纤维索减振效果优于钢索,振幅显著下降。(4)基于反应谱及地震时程分析理论,利用Midas Civil对斜拉-悬索管桥进行动力特性分析,选择合理的反应谱及地震波,确定合适的工况讨论结构在反应谱作用及一维、多维,一致、多点地震波激励下结构的动力响应,确定不同地震波对结构的影响;并将碳纤维索结构与钢索结构的变形、内力进行对比分析,讨论换索对结构的影响。结果表明:斜拉-悬索管桥相比其他普通桥梁频率较小,周期较长;无论是反应谱还是地震波,结构横向地震波响应最明显,且三维地震波激励下结构最危险,主要取决于结构自身横向刚度;换索后,结构的柔度有所增大,对结构地震响应较为有利。更多还原

【Abstract】 The long-span cable structure spanning system plays an indispensable role in the pipeline transportation project of oil and natural gas.Because the cable structure is exposed to the air for a long time,it is affected by the natural environment,temperature and humidity changes,and the cable is prone to rust.A cable accident occurred.The excellent physical and chemical properties of high-strength,high-strength,corrosion-resistant,and high-temperature resistant carbon fiber cables will effectively solve the problems faced by traditional steel cables.However,carbon fiber materials are rarely used in practical bridge projects.The relevant research results are weak and they are lightweight.Carbon fiber cable instead of the traditional steel cable will make the structure of the full bridge more gentler,and its changes in wind and seismic performance are particularly known.In order to solve the above problems,this paper takes a bridge as the engineering background,and comprehensively analyzes the dynamic characteristics of two types of long-span cable-stayed-suspension pipe bridges using steel and carbon fiber materials as cable structures.The main research contents are discussed.Conclusion as below:(1)Relying on the Weijing line Hanjiang spanning bridge and cable replacement project,analyzing the difference between the cable-stayed bridge and the ordinary highway bridge,summed up its own characteristics.Through the principle of axial equal strength,the traditional steel pipe of the pipe bridge and the traditional cable of the stay cable are replaced with carbon fiber materials,and the two types of replacement schemes of steel cable replacement and carbon fiber cable are provided.(2)Select the Davenport horizontal pulsating wind spectral density function,based on the autoregressive model in the linear phase filter method,simulate the three-dimensional pulsating wind field at the bridge span of the Hanjiang River through Matlab,and extract the turbulent parameters of the pulsating wind field as the cable wind.The boundary condition of vibration was studied.Through the Workbench work platform,the one-way fluid-solid coupling between the wind field and the cable was realized.The similarities and differences between the wind-induced vibration responses of the carbon fiber cable and the cable were calculated,and the changes in the aerodynamic characteristics of the bridge were analyzed.The results show that the use of carbon fiber cable as the cable material will increase the cable deformation and increase the cable stress.The wind-induced carbon fiber wind-induced vibration response displacement is larger than that of the traditional steel cable,but it decays faster with time.(3)Combining the mechanical characteristics of cable-stayed-suspension pipe bridges,the coupled-parameter vibration model of the bridge-tower cable-girder bridges is established.The Matlab tool is used for numerical calculation;Carbon fiber cable and steel cable are compared from the aspects of dynamic characteristics and amplitude.Parameter vibration performance,analysis of various impact parameters such as: bridge surface displacement,cable force,tower tower stiffness,cable damping and other parameters of the impact of vibration;Add viscous damper,damping damper model established,comparative analysis of two kinds of material pull Cable vibration control effect.The results show that the main resonance amplitude becomes larger and the subharmonic resonance decreases after the cable is replaced with carbon fiber cable.As a whole,the amplitude of the cable is changed and the parameter vibration performance is unfavorable.After the viscous damper is added for passive control,the carbon fiber cable is reduced.The vibration effect is better than the steel cable and the amplitude is significantly reduced.(4)Based on the response spectrum and seismic time history analysis theory,use Midas Civil to analyze the dynamic characteristics of cable-stayed-suspension pipe bridges,select the appropriate response spectrum and seismic wave according to the specifications,and select the appropriate working conditions to discuss the response spectrum effects of the structure.The dynamic response of the structure is considered;the dynamic response of the structure under the excitation of one-dimensional,multi-dimensional,uniform and multi-point seismic waves is considered,and the influence of different seismic waves on the structure is determined;and the deformation and internal force of the carbon fiber cable structure and the cable structure are compared and analyzed.Discuss the impact of the cable on the structure.The results show that the cable-stayed-suspended tube bridge has a smaller frequency and longer period.The response spectrum is the most obvious,whether it is the response spectrum or the seismic wave.It depends on the transverse stiffness of the structure and the structure excited by the 3D seismic wave.The most dangerous;after the cable is changed,although the flexibility of the structure is increased,the seismic response to the structure is favorable.更多还原