【作者】 李光强；

【导师】 何旭辉；

【作者基本信息】 中南大学 ， 土木工程， 2013， 硕士

【摘要】 由于目前我国铁路上还没有通车运营的铁路专用钢桁梁斜拉桥,对于风与列车荷载作用下铁路专用钢桁梁斜拉桥竖向振动及疲劳研究较少。在国家自然科学基金项目“强风环境下高速铁路车-桥系统气动特性和抗倾覆性能风洞试验研究(51178471)”的资助下,本文以南广铁路新建郁江钢桁梁斜拉桥为工程背景,研究了风与列车荷载作用下钢桁梁斜拉桥的竖向振动和斜拉索、关键杆件疲劳损伤和疲劳寿命,主要研究内容如下：(1)抖振时域分析。采用Deodatis谐波合成法模拟空间相关的脉动风速场,然后计算静风力、抖振力,根据自激力与节点位移的关系得到气动刚度矩阵和气动阻尼矩阵,通过Matrix27矩阵单元考虑自激力,利用ANSYS瞬态分析模块进行抖振时域分析。(2)车桥竖向耦合振动分析。采用德国低干扰功率谱模拟轨道的竖向不平顺,根据达朗贝尔原理推导了6个自由度的(车体沉浮、点头,前、后转向架的沉浮、点头)具有二系悬挂车辆模型的运动方程。采取较易实现的方法分析车桥竖向耦合振动：将车辆及桥梁在MATLAB及ANSYS分别求解,通过多次迭代来满足车辆、桥梁间的几何、力学耦合关系。(3)风荷载作用下车桥竖向耦合振动分析。车辆风荷载只考虑静风力和抖振力,推导了风作用在列车上时车辆模型的运动方程。横风作用下车桥竖向耦合分析方法同前面一样,研究了列车运行在桥梁的迎风侧时桥梁的竖向振动。(4)风与列车共同作用下构件的疲劳分析。根据前面的分析结果得到斜拉索锚固处考虑局部弯曲应力的应力时程和关键受力杆件的应力时程,运用雨流计数法对应力时程进行统计得到应力谱,考虑应力均值的影响,利用线形疲劳累积损伤理论计算了疲劳损伤和疲劳寿命。图148幅,表14个,参考文献55篇更多还原

【Abstract】 At present, there is no railway steel truss girder cable-stayed bridge opened to traffic in our country, therefore, research on vertical vibration and fatigue of steel truss girder cable-stayed bridge under wind and train loads is relatively few. With the support of the National Nature Science Foundation of China(NO.51178471),this paper analyses vertical vibration and fatigue of Yujiang steel truss girder cable-stayed bridge under wind and train load, the main research contents are as follows.(1) Time-domain buffeting analysis. Spatial fluctuating wind field of bridge site is simulated using Deodatis WAWS method in MATLAB, then static wind and buffeting force is computed. Aerodynamic stiffness matrix and damping matrix are obtained according to the relationship between self-excited force and nodal displacement, therefore,self-excited force could be taken into account using Matrix27elements. Time-domain buffeting analysis is done by ANSYS transient dynamic analysis.(2) Vehicle-bridge vertical coupling vibration. Track irregularity is simulated using German low interference power spectrum. Motion equations of two suspension systems vehicle model are derived according to the D’Alembert’s principle. The analysis method of vehicle-bridge vertical coupling vibration introduced this paper is relatively easy compared with previous studies, that is, motion equations of vehicle and bridge are solved respectively in MATLAB and ANSYS, and through multiple iterations to satisfy the geometric and mechanical coupling relationship between vehicle and bridge.(3) Vehicle-bridge vertical coupling vibration under crosswind. Only static wind force and buffeting force is computed for vehicle, then motion equations of vehicle model under crosswind are derived according to the D’Alembert’s principle. The analysis method is same as above, vertical vibration of the bridge is analyzed when train running on the windward side of the bridge.(4) Fatigue analysis of cable-stayed bridge under wind and train load. Stress time history of cables considering local bending stress and stress time history of key members are obtained through above analysis results. The rain flow counting method is used to get stress spectrum, then fatigue damage and fatigue life is computed according to linear fatigue cumulative damage theory considering the influence of the mean stress.更多还原