钢—混凝土组合箱梁剪力滞及滑移效应分析

发布时间：2018-03-26 03:47

本文选题：钢-混凝土组合箱梁　切入点：剪力滞效应　出处：《兰州交通大学》2017年硕士论文

【摘要】：钢-混凝土组合箱梁因为其优异的力学性能、出色的经济和使用效益、适合传统施工方法等优点,发展迅速。在竖向力的作用下,混凝土顶板和钢底板均存在明显的剪力滞效应,对剪力滞效应忽略会导致结构不安全。对于钢-混凝土组合箱梁,混凝土板与钢箱梁结合面的相对滑移不可忽略,相对滑移会使组合梁变形增大,也使组合梁内的应力重新分布,因此对钢-混凝土组合箱梁的剪力滞及滑移效应的分析很有必要。本文基于能量变分法,分别对不计入结合面滑移和计入结合面滑移的钢-混凝土组合箱梁剪力滞效应进行了理论分析研究,做了以下工作:首先,运用能量变分法,建立了不计结合面滑移的钢-混凝土组合箱梁剪力滞效应的控制微分方程,推导了典型边界条件下混凝土板和钢底板的应力解析解。由算例分析表明,组合箱梁上下翼板存在剪力滞后现象且符合剪力滞分布规律,解析解值与不计滑移的有限元模拟结果进行对比,基本吻合,证明了所推导的组合箱梁剪力滞效应解析解的正确性。然后建立了考虑结合面滑移和剪力滞双重效应的组合箱梁力学模型,推导了典型边界条件下组合箱梁的挠度和应力解析解。结合算例分析,解析解值与计入滑移的有限元模拟结果吻合较好,说明所推导的考虑滑移和剪力滞双重效应下组合箱梁解析解的正确性。最后,对比有滑移和无滑移情况下的挠度值,简支组合箱梁和悬臂组合箱梁在竖向荷载作用下,有滑移挠度值大于无滑移的挠度值,表明滑移会使组合箱梁的挠度增大。结合算例,对比混凝土板、钢底板中计入滑移和不计滑移的应力解析解值,也对比计入滑移和不计滑移的有限元应力值,不同边界和荷载下,计入滑移的应力都小于不计滑移的应力,表明滑移使组合箱梁内的应力重新分布,使混凝土板和钢底板中应力减小,减弱了剪力滞效应。
[Abstract]:Steel-concrete composite box girder has developed rapidly because of its excellent mechanical properties, excellent economic and operational benefits, suitable for traditional construction methods, etc. Under the action of vertical force, There is obvious shear lag effect on concrete roof and steel bottom slab. Ignoring shear lag effect will lead to structural insecurity. For steel-concrete composite box girder, the relative slip between concrete slab and steel box girder can not be ignored. Relative slippage will increase the deformation of composite beam and redistribute the stress in composite beam. Therefore, it is necessary to analyze the shear lag and slip effect of steel-concrete composite box girder. In this paper, the shear lag effect of steel-concrete composite box girders without and without joint slip is studied in theory. The following works are done: firstly, the energy variation method is used to analyze the shear lag effect of steel-concrete composite box girder. The governing differential equation of shear lag effect of steel-concrete composite box girder is established, and the analytical solution of stress of concrete slab and steel bottom slab under typical boundary conditions is derived. The shear lag phenomenon exists in the upper and lower wing plates of the combined box girder and conforms to the law of shear lag distribution. The analytical solution is in good agreement with the finite element simulation results without taking into account slippage. It is proved that the analytical solution of shear lag effect of combined box girder is correct, and then the mechanical model of combined box girder considering the double effects of slip and shear lag is established. The analytical solutions of deflection and stress of composite box girder under typical boundary conditions are derived. The results show that the analytical solution of the composite box girder is correct considering the double effects of slip and shear lag. Finally, the deflection of the simple supported composite box girder and the cantilever composite box girder under vertical load is compared with the deflection of the composite box girder with and without slip. The slip deflection value is larger than the non-slip deflection value, which indicates that the slip will increase the deflection of the composite box girder. By comparing the finite element stress values with and without slip, the stress with slip is smaller than that without considering slip under different boundaries and loads, which indicates that slip redistributes the stress in composite box girder. The stress in concrete slab and steel floor is reduced, and the shear lag effect is weakened.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441

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