地震荷载作用下曲线箱梁剪力滞效应研究

发布时间：2018-01-09 01:20

本文关键词：地震荷载作用下曲线箱梁剪力滞效应研究　出处：《武汉工程大学》2014年硕士论文　论文类型：学位论文

【摘要】：曲线箱梁桥由于自身特点而在工程中应用广泛，但箱型截面所带来的剪力滞效应对桥梁的安全会造成一定的影响，同时，曲率的存在使桥梁中存在着弯扭耦合效应，在一定程度上又会加剧剪力滞效应的影响。国内外学者对曲线箱梁剪力滞效应做了大量的研究工作，取得了一些成果，但这些研究大部分都基于静荷载，对动荷载作用下的剪力滞效应鲜有涉及，而实际的桥梁结构处在动荷载作用下，，基于静荷载的分析结果并不能完全满足工程实际需求。为此，本文采用有限元法，运用有限元分析软件ANSYS建立曲线箱梁的有限元分析模型，分析在其地震荷载作用下的剪力滞效应，主要的研究内容如下： 1.分别建立梁单元、壳单元和三维实体单元的有限元分析模型，进行了各分析模型的动力特征分析和时程分析，结果表明壳单元分析模型精度较高计算也较为高效。 2.进行了曲线箱梁有限元分析模型在地震荷载作用下的时程分析，并采用应力取平均值来代替初等梁理论计算值的简化的计算方法计算节点的剪力滞系数，结果表明在地震荷载作用下节点的剪力滞系数的值在基准值附近波动，荷载大小的变化对剪力滞效应的影响是次要的。 3.进行在地震荷载下，曲率半径、腹板间距、箱梁高度以及腹板厚度对剪力滞效应影响的分析，得到了这些结构参数对剪力滞效应的影响规律，结果表明曲率半径和腹板间距的变化对剪力滞效应的影响明显。以上的研究结果对工程应用具有重要的参考价值。
[Abstract]:Curved box girder bridge is widely used in engineering because of its own characteristics, but the shear lag effect brought by box section will have a certain impact on the safety of the bridge, at the same time. The existence of curvature makes the coupling effect of bending and torsion exist in the bridge, to a certain extent, it will aggravate the influence of shear lag effect. Scholars at home and abroad have done a lot of research work on the shear lag effect of curved box girder. Some achievements have been made, but most of these studies are based on static load, and the shear lag effect under dynamic load is rarely involved, but the actual bridge structure is under dynamic load. The analysis results based on static load can not fully meet the actual needs of the project. Therefore, the finite element analysis model of curved box girder is established by using finite element method and finite element analysis software ANSYS. The shear lag effect under the earthquake load is analyzed. The main research contents are as follows: 1. The finite element analysis models of beam element, shell element and three-dimensional solid element are established, and the dynamic characteristic analysis and time history analysis of each analysis model are carried out. The results show that the accuracy of the shell element analysis model is higher and the calculation is more efficient. 2. The time-history analysis of the finite element analysis model of curved box girder under the action of earthquake load is carried out, and the shear lag coefficient of the node is calculated by using the mean value of stress instead of the simplified calculation method of the theoretical calculation value of the elementary beam. The results show that the shear lag coefficient of the joints fluctuates near the reference value under the earthquake load, and the influence of the load magnitude on the shear lag effect is secondary. 3. The influence of curvature radius, web spacing, box girder height and web thickness on shear lag effect is analyzed, and the influence of these structural parameters on shear lag effect is obtained. The results show that the changes of curvature radius and web spacing have obvious influence on the shear lag effect. The above research results have important reference value for engineering application.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U442.55

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