斜拉桥扁平钢箱梁局部稳定性研究
发布时间：2019-02-22 09:29
【摘要】：随着我国大跨径桥梁的迅速发展,扁平钢箱梁的应用越来越广泛,其局部稳定问题日益突出,本文在总结中外学者研究成果的基础上,对扁平钢箱梁进行局部稳定研究,主要做了以下工作：(1)介绍了斜拉桥发展历程及现状；分析了扁平钢箱梁的构造和力学特性：对桥梁结构的稳定问题、局部稳定理论进行了概述；(2)研究了四边简支板的屈曲临界应力的理论解,然后用Timoshenko法(能量法)和比拟正交异性板法(静力法)推导了加劲板的屈曲临界应力理论解；(3)介绍了几何非线性的成因及其类型,用ANSYS建立了薄板、开口及闭口加劲板的有限元模型,分析了几何非线性对其承载力的影响,得到了荷载与位移曲线图。(4)用ANSYS建立了薄板、开口及闭口肋加劲板有限元模型,对它们进行了屈曲分析,得到了第一阶屈曲系数和屈曲应力及屈曲时的变形形态,分析了影响加劲板屈曲的因素,即板厚、肋条间距及刚度、横隔板的间距,在分析的基础上得出了各因素对加劲板屈曲影响的规律。(5)对工程背景中的扁平钢箱梁进行了有限元模型分析,可知整个梁段在进行屈曲分析时横隔板最先发生屈曲。(6)概述了肋条刚度对加劲板的影响,提出合理刚度比的概念,分析了加劲板的肋条和母板同时局部屈曲时所要刚度比的规律。
[Abstract]:With the rapid development of long-span bridges in China, the application of flat steel box girder is becoming more and more extensive, and the problem of local stability is becoming more and more prominent. In this paper, the local stability of flat steel box girder is studied on the basis of summing up the research results of Chinese and foreign scholars. The main work is as follows: (1) the development history and current situation of cable-stayed bridge are introduced; The structural and mechanical properties of flat steel box girder are analyzed. The stability problem of bridge structure and the theory of local stability are summarized. (2) the theoretical solution of buckling critical stress of simply supported plates with four edges is studied, and the theoretical solution of buckling critical stress of stiffened plates is derived by using Timoshenko method (energy method) and analogy orthotropic plate method (static method). (3) the causes and types of geometric nonlinearity are introduced. The finite element model of thin plate, open and closed stiffened plate is established by ANSYS, and the influence of geometric nonlinearity on its bearing capacity is analyzed. The curves of load and displacement are obtained. (4) the finite element model of thin plate, open and closed rib stiffened plate is established by ANSYS, and their buckling analysis is carried out, and the first order buckling coefficient, buckling stress and deformation pattern during buckling are obtained. The factors affecting buckling of stiffened plate are analyzed, such as thickness of plate, spacing and stiffness of ribs, and spacing of transverse partition. On the basis of analysis, the influence of various factors on buckling of stiffened plate is obtained. (5) finite element model analysis of flat steel box girder in engineering background is carried out. It can be seen that the first buckling occurs in the whole beam section when the transverse diaphragm is buckled. (6) the influence of rib stiffness on stiffened plate is summarized, and the concept of reasonable stiffness ratio is proposed. The stiffness ratio of stiffened plate is analyzed when the rib and the motherboard are buckled at the same time.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.27
，
本文编号：2428081
[Abstract]:With the rapid development of long-span bridges in China, the application of flat steel box girder is becoming more and more extensive, and the problem of local stability is becoming more and more prominent. In this paper, the local stability of flat steel box girder is studied on the basis of summing up the research results of Chinese and foreign scholars. The main work is as follows: (1) the development history and current situation of cable-stayed bridge are introduced; The structural and mechanical properties of flat steel box girder are analyzed. The stability problem of bridge structure and the theory of local stability are summarized. (2) the theoretical solution of buckling critical stress of simply supported plates with four edges is studied, and the theoretical solution of buckling critical stress of stiffened plates is derived by using Timoshenko method (energy method) and analogy orthotropic plate method (static method). (3) the causes and types of geometric nonlinearity are introduced. The finite element model of thin plate, open and closed stiffened plate is established by ANSYS, and the influence of geometric nonlinearity on its bearing capacity is analyzed. The curves of load and displacement are obtained. (4) the finite element model of thin plate, open and closed rib stiffened plate is established by ANSYS, and their buckling analysis is carried out, and the first order buckling coefficient, buckling stress and deformation pattern during buckling are obtained. The factors affecting buckling of stiffened plate are analyzed, such as thickness of plate, spacing and stiffness of ribs, and spacing of transverse partition. On the basis of analysis, the influence of various factors on buckling of stiffened plate is obtained. (5) finite element model analysis of flat steel box girder in engineering background is carried out. It can be seen that the first buckling occurs in the whole beam section when the transverse diaphragm is buckled. (6) the influence of rib stiffness on stiffened plate is summarized, and the concept of reasonable stiffness ratio is proposed. The stiffness ratio of stiffened plate is analyzed when the rib and the motherboard are buckled at the same time.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.27
，
本文编号：2428081
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