下承式系杆拱桥吊杆疲劳损伤研究

发布时间：2018-04-20 06:05

本文选题：钢管混凝土 + 荷载谱　；参考：《重庆交通大学》2015年硕士论文

【摘要】：随着我国进入21世纪,在改革开放的推动下,我国基础设施建设有了突飞猛进的增长。伴随日益加剧的交通压力,我国高速公路上的桥梁都在满负荷运营,并且服役时间普遍高于27年。可想而知由车辆带来的疲劳损伤则成为了桥梁最大的安全隐患。钢管混凝土拱桥以其自重轻,跨越能力大,力学线条优美受到广大桥梁建设者的青睐。而拱桥吊杆作为桥梁结构的主要传力构件,其健康状况关系到整个桥梁的运营安全。因此,本文结合北京至昆明108国道线云南境内的一处下承式钢管混凝土拱桥为原型,利用通用有限元计算软件MIDAS/CIVIL,模拟分析该拱桥在车辆荷载作用下其典型吊杆的疲劳性能,并通过改变拱桥设计参数,提出改善拱桥吊杆疲劳设计参考意见。主要研究内容及结论如下:①运用MATLAB软件编程以实现服从对数正态分布的随机车辆荷载谱模拟,将该荷载谱随机作用于桥面行车道上。基于1860级钢绞线的疲劳S—N曲线分析理论,再利用雨流计数法计算各个典型吊杆在疲劳荷载谱下的等效应力幅以及等效应力循环次数。并基于Miner线性损伤累积理论对该下承式系杆拱桥吊杆的疲劳寿命做出了评估,具备一定的工程参考价值。②通过改变拱桥的某些疲劳设计参数的情况下进行了共6种情况的吊杆疲劳性能对比。分析发现:1)布置更有利于吊杆的协同受力,能良好的改善吊杆疲劳性能,即使在某根吊杆断裂的情况下也不会导致整桥的垮塌;2)杆间距的对吊杆疲劳性能的对比则要根据实际桥梁跨径确定,一般控制在4~10米。过大的吊杆间距对吊杆抗疲劳设计不利;3)工程造价,适当增大吊杆截面积对吊杆抗疲劳设计有利,尤其是边吊杆;4)刚度比过大对吊杆受力极为不利,不利于抗疲劳设计;5)比对吊杆的抗疲劳设计影响甚微,可根据实际情况做最佳调整;6)边吊杆离拱脚距离只对边吊杆的抗疲劳性能有利,而对其他吊杆的疲劳性能改善作用微小。
[Abstract]:As China enters the 21st century, the infrastructure construction of our country has increased by leaps and bounds under the impetus of reform and opening up. With the increasing traffic pressure, the bridges on the highway in our country are operating at full load, and the service time is generally longer than 27 years. It can be imagined that the fatigue damage caused by the vehicle has become the biggest safety hazard of the bridge. Concrete-filled steel tubular arch bridge is favored by bridge builders for its light weight, large span capacity and beautiful mechanical lines. As the main force transfer component of the bridge structure, the health of arch bridge suspenders is related to the operation safety of the whole bridge. Therefore, in this paper, a through concrete filled steel tube arch bridge in Yunnan Province of Beijing-Kunming 108 National Highway is used as a prototype, and the fatigue performance of typical suspenders of the arch bridge under vehicle load is simulated and analyzed by using the universal finite element software Midas / CIVIL. By changing the design parameters of the arch bridge, the paper puts forward some suggestions for improving the fatigue design of the suspenders of the arch bridge. The main research contents and conclusions are as follows: 1. MATLAB software is used to simulate the load spectrum of a random vehicle with logarithmic normal distribution, and the load spectrum is applied randomly on the bridge deck lane. Based on the fatigue S-N curve analysis theory of 1860 grade steel strand, the equivalent stress amplitude and the equivalent stress cycle number of each typical suspender under the fatigue load spectrum are calculated by the rain flow counting method. Based on the Miner linear damage accumulation theory, the fatigue life of the suspension rod of the through arch bridge is evaluated. By changing some fatigue design parameters of arch bridge, the fatigue performance of suspension rod is compared in 6 cases. It is found that the arrangement of the lifting rod is more favorable to the cooperative force of the suspender and can improve the fatigue performance of the suspender. Even if a suspender is broken, it will not lead to the collapse of the whole bridge. The comparison of the fatigue performance of the suspension rod should be determined according to the actual span of the bridge, and generally controlled at 4m. The excessive distance between the suspenders is disadvantageous to the anti-fatigue design of the suspenders (3) the proper increase of the cross section area of the suspenders is beneficial to the anti-fatigue design of the suspenders, especially the excessive stiffness ratio of the side suspenders is extremely disadvantageous to the stress of the suspenders. It has little effect on the anti-fatigue design of the suspenders, and can be adjusted best according to the actual situation. The distance from the arch foot of the suspenders is only favorable to the anti-fatigue performance of the side suspenders, but the fatigue property of the other suspenders can be improved slightly.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.4;U448.225

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