环境温度对三塔两跨悬索桥结构静动力特性的影响

Effect of Environmental Temperature on Static&Dynamic Behavior of Three-tower&Two-span Suspension Bridge

以泰州大桥为对象,分析了整体结构温度变化对于三塔两跨悬索桥结构静动力特性的影响.从Euler-Bernoulli梁出发,导出了杆件单元的内力变化后的动力特性分析等效刚度表达式.通过温度变化后大跨桥梁的静力分析,得到构件单元内力增量,计算等效刚度,进而计算温度变化后的动力特性.利用ANSYS的二次开发功能,编制了相应的宏命令和分析模块,分析了结构整体温度变化对大桥动力特性的影响.结果表明:环境温度变化对于泰州大桥结构静动力特性影响明显,温度的变化与大桥自振频率的变化呈反比关系.在进行大跨桥梁试验模态分析,以及结构损伤识别等研究中应考虑环境温度的影响.

As the object of Taizhou Yangtze River Bridge,effect of the global structure temperature variation of on dynamic characteristics of three-tower and two-span suspension bridge are discussed in this paper.The dynamic characteristics of three-towers two-spans suspension bridge is analyzed at different global temperature.From the Euler-Bernoulli beam,the equivalent stiffness expression of dynamic characteristics analysis after the internal force of the link element has changed is conducted.According to the static analysis of long-span bridge after temperature variation,the internal force increment of link element can be derived.The equivalent stiff is obtained.Then the dynamic characteristics after the variation of temperature are formulated.The redevelop function of ANSYS has been used for the purpose of programming corresponding macro commands and analysis modules to investigate the influence of global temperature variation on dynamic characteristics of Taizhou Yangtze River Bridge.The result shows that environmental temperature variation has a remarkable influence on the static and dynamic characteristics of Taizhou Yangtze River Bridge,and the temperature variation is inversely related to that of the vibration frequency for bridge.