重载交通作用下桥梁结构的疲劳损伤数值分析

发布时间：2018-01-18 01:23

本文关键词：重载交通作用下桥梁结构的疲劳损伤数值分析　出处：《河北工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国是一个桥梁大国,桥梁结构的安全运营关系着国民经济健康、高质量的发展,近年来随着公路交通运输事业的快速发展,各地公路桥梁上运行的汽车载重均有了不同程度的增长。工程结构事故中,因疲劳损伤破坏而引发的事故占据着很大的比例,且结构的疲劳破坏在宏观上属于脆性破坏,在破坏之前没有明显的征兆。桥梁在昼夜不停的重载车辆往复行驶作用下必然会遭受到疲劳损伤,且车辆载重的增加会引起疲劳应力幅的增加,疲劳应力幅是影响结构疲劳寿命的一个重要因素。因而对桥梁结构进行重载交通作用下的疲劳损伤分析有其必要性,对于我们实时掌握桥梁的安全运营状况有着重要的参考依据。本文围绕着重载交通对桥梁结构的疲劳损伤问题,开展了相关的研究工作。针对桥梁结构遭受疲劳破坏的工程事故以及重载交通运输现状做了介绍,收集整理了国内外关于桥梁疲劳性能的研究进展资料。研究总结了预应力钢筋混凝土桥梁疲劳破坏的机理和疲劳寿命分析的方法理论。根据实地交通调查的数据结果,进行统计分析,找出了随机车辆的分布规律,为了模拟桥梁上实际运营的车辆对桥梁产生的疲劳损伤,本文借助Matlab软件,结合车辆的分布规律,编写了随机车流生成程序,通过参数化设置,可以生成符合不同需求的随机车流。根据线性疲劳累积损伤原理,建立了适用于调查路段桥梁的标准疲劳车模型。运用大型有限元分析软件,建立了16m预应力钢筋混凝土空心板梁的实体有限元模型,并用宏命令编写了随机车流加载程序JIAZAI,实现了将Matlab生成的随机车流加载到有限元模型上模拟随机车辆过桥。运用瞬态动力分析方法进行车辆过桥的加载求解,运用线性疲劳累积损伤理论,通过模拟各典型车辆在不同车间距以及不同过桥速度情况下的疲劳损伤,对比了车速以及车间距对桥梁疲劳损伤的影响。将一般运营状态下和密集运营状态下的随机车流加载到有限元模型上,对比了两者的不同影响,分析对比了标准疲劳车作用与一般运营状态下的等效应力幅。
[Abstract]:Our country is a big country of bridge, the safe operation of bridge structure is related to the healthy and high quality development of national economy. In recent years, with the rapid development of highway transportation. In the engineering structure accidents, the accidents caused by fatigue damage occupy a large proportion. And the fatigue damage of the structure belongs to brittle failure in macroscopic, and there is no obvious sign before the failure. The bridge will suffer fatigue damage under the action of the heavy load vehicle driving around the clock. And the increase of vehicle load will cause the increase of fatigue stress amplitude. The fatigue stress amplitude is an important factor affecting the fatigue life of the structure, so it is necessary to analyze the fatigue damage of the bridge structure under the heavy load traffic. This paper focuses on the fatigue damage of bridge structure caused by heavy load traffic. The related research work is carried out. The engineering accident of fatigue damage of bridge structure and the current situation of heavy haul traffic and transportation are introduced. This paper collected and sorted out the research progress data of bridge fatigue performance at home and abroad, summarized the fatigue failure mechanism and fatigue life analysis method theory of prestressed reinforced concrete bridge, and based on the data of field traffic investigation, summarized the fatigue failure mechanism of prestressed reinforced concrete bridge and the method theory of fatigue life analysis. The result. Statistical analysis to find out the distribution of random vehicles, in order to simulate the actual operation of the bridge vehicle fatigue damage to the bridge, this paper with the help of Matlab software, combined with the distribution law of vehicles. A program for generating random traffic flow is written. By parameterized setting, random traffic flow can be generated according to different requirements, according to the principle of linear fatigue cumulative damage. The standard fatigue vehicle model suitable for the investigation of bridges is established and the solid finite element model of 16m prestressed reinforced concrete hollow slab beam is established by using the large-scale finite element analysis software. The random traffic loading program JIAZAI is written with macro command. The random vehicle flow generated by Matlab is loaded into the finite element model to simulate the random vehicle crossing bridge. The transient dynamic analysis method is used to solve the loading problem of the bridge and the linear fatigue cumulative damage theory is used. The fatigue damage of typical vehicles under different vehicle spacing and crossing speed is simulated. The effects of vehicle speed and vehicle spacing on fatigue damage of bridges are compared. The random traffic flow in general operation state and in dense operation state is loaded into the finite element model, and the different effects are compared. The equivalent stress amplitude of the standard fatigue vehicle is analyzed and compared with that of the normal operation state.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.4

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