波形钢腹板PC组合箱梁腹板剪切屈曲稳定性能研究

发布时间：2018-04-04 05:33

本文选题：波形钢腹板　切入点：组合箱梁桥　出处：《兰州交通大学》2015年硕士论文

【摘要】：波形钢腹板PC组合箱梁桥结构因能够充分利用混凝土和钢腹板的材料特点及结构受力明确等优势而受到国内外众多设计师的青睐,然而国内对该桥型的理论研究尚处于探索阶段,实际工程应用较少,设计与施工水平有待进一步提高。在波形钢腹板PC组合箱梁抗剪承载力验算中,波形钢腹板的剪切屈曲稳定扮演着不可替代的控制因素,因此对其进行定性定量分析显得异常必要。本文在分析国内外现有研究成果和工程设计实例的基础上,采用大型通用有限元程序ANSYS并结合现有理论,建立不同几何构造参数的腹板空间有限元模型,分别进行线性、非线性有限元分析计算,研究成果可为波形钢腹板在实桥中的尺寸设计提供理论依据。主要完成工作如下;一、在大量阅读国内外有关该组合梁桥研究成果的基础上,对波形钢腹板屈曲稳定理论进行了整理,总结了腹板局部屈曲强度、整体屈曲强度及合成屈曲强度的线弹性理论公式,及考虑塑性变形的非线性经验公式。二、采用ANSYS建立空间有限元模型,建模过程中假定剪力完全由波形钢腹板承担,即腹板处于纯剪切受力状态,波腹板几何尺寸在参考鄄城黄河大桥的基础上变化,在理想线弹性条件下对结构进行特征值屈曲分析,分别研究腹板波形形状(波高、波折角度、直板长度)、板厚、腹板高度和横隔板间距等变化对结构屈曲模态和屈曲极限荷载的影响规律,并将不同算例代入弹性屈曲理论公式进行计算,对各计算理论的准确性和适用性进行了评价和验证。三、在腹板特征值屈曲分析的基础上,通过ANSYS非线性屈曲分析功能,采用一致缺陷模态法引入结构初始几何缺陷,并计入材料非线性、几何非线性和大变形效应等,启用ANSYS弧长搜索功能,对波形钢腹板全过程屈曲响应进行跟踪分析。研究各几何构造参数在非线性有限元计算条件下腹板剪切屈曲全过程荷载-位移曲线及屈曲极限荷载变化趋势,并对屈曲后行为进行研究分析。四、将有限元计算值和理论计算结果进行对比分析,对线弹性和非线性范围内各理论公式的适用性进行评价,给出了相应计算建议采用的理论公式。本文通过对波形钢腹板剪切屈曲稳定性能的研究,希望研究内容能为同类型桥梁的计算设计和施工工艺提供一定的理论参考。
[Abstract]:The structure of PC composite box girder bridge with corrugated steel webs is favored by many designers at home and abroad because it can make full use of the material characteristics of concrete and steel webs and the clear force of the structure.However, the theoretical study of the bridge is still in the exploratory stage, the practical engineering application is relatively few, and the level of design and construction needs to be further improved.The shear buckling stability of corrugated steel webs plays an irreplaceable control factor in the checking calculation of shear bearing capacity of PC composite box girder with corrugated steel webs, so it is very necessary to make qualitative and quantitative analysis of the shear buckling stability of corrugated steel webs.In this paper, based on the analysis of existing research results and engineering design examples at home and abroad, a web space finite element model with different geometric construction parameters is established by using the large and universal finite element program ANSYS and the existing theory.Nonlinear finite element analysis and calculation, the research results can provide theoretical basis for the size design of corrugated steel web in the real bridge.The main works are as follows: firstly, based on the domestic and foreign research results of the composite girder bridge, the buckling stability theory of the corrugated steel web is sorted out, and the local buckling strength of the web is summarized.The linear elastic theory formula of global buckling strength and synthetic buckling strength, and the nonlinear empirical formula considering plastic deformation.Secondly, the spatial finite element model is established by ANSYS. In the process of modeling, it is assumed that the shear force is borne entirely by the corrugated steel web, that is, the web is in the state of pure shear force, and the geometric dimension of the wave web is changed on the basis of referring to Juancheng Yellow River Bridge.Under the ideal linear elastic condition, the eigenvalue buckling analysis of the structure is carried out, and the shape of the web waveform (wave height, wave angle, length of the straight plate, thickness of the plate) is studied, respectively.The influence of the web height and the spacing of the transverse spacer on the buckling mode and ultimate load of the structure is studied. Different examples are added to the elastic buckling theory formula to evaluate and verify the accuracy and applicability of the calculation theory.Thirdly, on the basis of eigenvalue buckling analysis of web, through ANSYS nonlinear buckling analysis function, the uniform defect mode method is used to introduce the initial geometric defects of the structure, including material nonlinearity, geometric nonlinearity and large deformation effect, etc.The whole buckling response of the corrugated steel web is analyzed by using the ANSYS arc length search function.The load-displacement curves and ultimate buckling load trends of web shear buckling under nonlinear finite element method are studied and the post-buckling behavior is analyzed.Fourthly, the finite element calculation value and the theoretical calculation result are compared and analyzed, the applicability of each theoretical formula in the range of linear elasticity and nonlinearity is evaluated, and the corresponding theoretical formula suggested for calculation is given.In this paper, the shear buckling stability of corrugated steel webs is studied. It is hoped that the research can provide a theoretical reference for the calculation, design and construction of the same type bridges.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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