箱型梁剪力滞和剪切变形双重效应研究

发布时间：2018-05-15 02:01

本文选题：剪力滞 + 剪切变形　；参考：《广西大学》2014年硕士论文

【摘要】：箱型梁结构因具有良好的结构性能而在大跨度桥梁结构中广泛采用。具有宽大翼板的箱型梁结构在对称弯曲荷载作用下,剪力滞效应明显,导致翼板正应力沿横向不均匀分布,结构的整体抗弯性能也有所降低,使得箱梁结构存在结构失稳或局部破坏的安全隐患,在桥梁建设中不容忽视。另一方面,箱型梁横截面腹板面积较小,结构的抗剪能力差,剪切效应明显,忽略该效应将低估箱梁结构响应量,严重影响结构安全性。本文围绕箱型梁剪力滞效应和剪切效应开展了相关研.究。 (1)研究发展了基于附加挠度的箱型梁剪力滞解析理论及其一维离散有限元法,并将其应用于变高度箱梁中。结合最小势能原理建立了基于附加挠度的箱型梁剪力滞效应分析能量变分法,并基于挠度定义剪力滞系数；推导了基于附加挠度的箱型梁剪力滞效应分析的一维离散有限元格式,位移函数采用精度较高的三次插值求解变截面箱型梁的剪力滞效应。 (2)建立了基于附加挠度的箱型梁剪力滞和剪切双重效应分析的能量变分法。分析了跨高比和宽高比对剪力滞效应和剪切效应的影响规律；提出附加轴力比的概念,验证纵向位移函数的合理性及截面轴向力平衡条件。 (3)建立了基于附加挠度的箱型梁剪力滞和剪切变形双重效应分析的一维离散有限元法。以附加挠度、转角和挠度及其一阶导数作为节点位移参数,导出势能泛函的矩阵表达式,并表出单元刚度矩阵的显式表达式,为复杂结构的剪力滞和剪切变形双效应研究提供具有较高计算精度和计算效率的数值分析方法。
[Abstract]:Box girder structure is widely used in long-span bridge structure because of its good structural performance. Under symmetrical bending load, the shear lag effect of the box girder structure with wide wing plate is obvious, which leads to the uneven distribution of normal stress along the transverse direction, and the overall bending resistance of the structure is also reduced. It makes box girder structure unstable or local damage, which can not be ignored in bridge construction. On the other hand, the cross section web area of box girder is small, the shear capacity of the structure is poor, and the shear effect is obvious. Neglecting this effect will underestimate the response of box girder structure and seriously affect the structural safety. This paper focuses on the shear lag effect and shear effect of box girder. Research. 1) the analytical theory of box girder shear lag based on additional deflection and its one-dimensional discrete finite element method are developed and applied to variable height box girder. Based on the principle of minimum potential energy, the energy variation method for the analysis of shear lag effect of box girder based on additional deflection is established, and the shear lag coefficient is defined based on deflection. The one-dimensional discrete finite element scheme for box girder shear lag analysis based on additional deflection is derived. The displacement function is used to solve the shear lag effect of box girder with variable cross-section by cubic interpolation with high precision. (2) an energy variational method for the analysis of shear lag and shear double effects of box girder based on additional deflection is established. The influence of span height ratio and width height ratio on shear lag effect and shear effect is analyzed, and the concept of additional axial force ratio is proposed to verify the rationality of longitudinal displacement function and the axial force balance condition of section. A one-dimensional discrete finite element method is developed to analyze the double effects of shear lag and shear deformation of box girder based on additional deflection. Taking the additional deflection, rotation angle, deflection and their first derivative as the node displacement parameters, the matrix expression of the potential energy functional is derived, and the explicit expression of the element stiffness matrix is given. A numerical analysis method with high accuracy and efficiency is provided for the study of the double effects of shear lag and shear deformation of complex structures.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.213

【参考文献】