【作者】 尹树桃；

【导师】 许福友；

【作者基本信息】 大连理工大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 悬索桥结构以其外形美观、跨越能力强、经济指标良好和设计施工成熟等优点,在国内外油气管道桥建设中被大量采用。与普通悬索桥相比,管道悬索桥刚度更小、风振问题更突出。本文以某油气管道悬索桥方案为工程背景,对其动力特性、静风响应、颤振稳定性、抖振响应等方面展开研究,主要工作及结论如下：(1)运用索单元初应变迭代方法得到合理成桥线形,对其进行了动力特性分析,研究了结构参数对管道悬索桥自振特性的影响。结果表明：管道悬索桥振型密集,振动特性复杂；扭弯比低,侧向刚度较弱,低阶振型均是以加劲梁振动为主的振型；设置抗风索能显著提高结构侧向刚度,增加抗风索的预拉力可提高结构侧弯和扭转刚度,减小抗风索倾角可以提高结构竖弯刚度；设置共轭索对高阶振动抑制作用较大。(2)通过节段模型测力实验得到静力三分力系数,分析了篦子板对三分力的影响,运用增量与内外两重迭代法进行了静风响应分析。结果表明：管道悬索桥的静风失稳过程是静风荷载非线性与结构非线性相互影响的结果；风荷载初始攻角增大,静风稳定性降低；设置抗风索,静风失稳风速可提高20%以上；初始攻角,附加攻角,缆索系统风荷载,抗风索对静风响应均存在影响。(3)通过节段模型测振实验,得到不同攻角下的颤振临界风速,对颤振稳定性进行评价；运用最小二乘法识别了均匀流场中模型的颤振导数,为颤抖振分析提供气动自激力参数。(4)运用谐波合成法模拟了全桥的脉动风场,运用Davenport抖振力理论建立了全桥抖振力分析模型,通过ANSYS中的Matrix27单元实现了对自激力的气动刚度和气动阻尼的模拟,考虑气动和几何非线性,运用瞬态动力分析进行了抖振响应时域分析。更多还原

【Abstract】 With its beautiful appearance, long span, good economic indicators, the advantages of mature design and construction, suspension bridge has been widely adopted for oil and gas pipeline bridge. Compared with ordinary suspension bridge, pipeline suspension bridge’s stiffness is smaller, wind-induced vibration problem is more prominent. In this paper, taking one oil and gas pipeline suspension bridge as example, those keypoints had been studied on: dynamic characteristics, aerostatic response, flutter stability and buffeting response. The main work and conclusions are as follows:(1) Through the method of link elements initial strain iteration, the bridge reasonable linear shape has been obtained. The dynamic analysis has been carried out, the design parameter change to the pipeline hanging bridge self oscillation characteristic influence has also been studied. The result indicated:The pipeline suspension bridge mode is crowded, the vibration characteristic is complex; The frequency ratio of torisional to vertical bending is low, the lateral rigidity is weak, the low-order mode of vibration is by the stiffening girder vibration lineup primarily; The installment of windcables can obviously enhance the structure lateral rigidity, increases the wind cables pretension strength to be possible to enhance the structure lateral bending and the torsional rigidity, reduce the wind resistant rope inclination angle to be possible to enhance the structure to set upright the curved rigidity; The establishment conjugate cable is big to the higher order vibration abatement function.(2) The paper obtained three force component coefficients through the static stage section model wind tunnel test, analyzed the influences on three force component by grate plate. The paper has carried on the static wind stability analyses and the still wind response analysis using the increase with the inside and outside twofold repetitive process. The result indicated:The pipeline suspension bridge’s aerostatic divergence process is result from the aerostatic load and the structure nonlinearities; The wind load initial angle of attack increases, the static wind stability reduces; The establishment of windcable may enhance aerostatic divergence speed by 20%; The initial angle of attack, the additional angle of attack, the cable system wind load, the windcable’ establishment has influences on the aerostatic response. (3) The paper has obtained flutter critical wind speed under the different angle of attack through the section model dynamic wind tunnel test, has carried on the appraisal to the flutter stability; has distinguished the smooth flows flutter derivative using the least squares method, provides the self-excitation force parameter for the buffeting response analysis.(4) The paper has simulated the entire bridge’s pulsation wind field using the WAWS, has established the entire bridge buffeting strength model using the Davenport buffeting strength theory, has been realized through the ANSYS in matrix27 element to the self-excitation strength aerodynamic rigidity and damping simulation, considered that aerodynamic and geometric nonlinearity, has carried on the buffeting response time domain analysis using the transient state mechanical analysis.更多还原