桁腹式组合桁梁桥的关键节点及其剪力滞效应研究

发布时间：2018-02-12 04:14

本文关键词： 桁腹式组合桁梁桥节点剪力滞效应受力性能破坏形态　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：桁腹式组合桁梁桥凭借良好的经济性、更强的跨越能力和建筑维护方便的特点,在实际工程中具有广阔的应用前景。桁腹式组合桁梁桥节点是桁腹式组合桁梁桥的关键构件,目前对桁腹式组合桁梁桥节点的水平抗剪性能认识较深入,对考虑腹杆弯矩、桥面板的竖向挠度以及对节点的影响下的受力性能、塑性分布和破坏形态,以及节点非连续地分布引起的剪力滞效应均缺乏足够的了解。本文拟通过有限元模拟和试验研究,深入了解桁腹式组合桁梁桥节点的受力性能、构件塑性分布和破坏模式,以及桁腹式组合桁梁桥的剪力滞效应。本文的内容主要包括以下三个方面:桁腹式组合桁梁桥节点的非线性有限元分析。通过ABAQUS建立桁腹式组合桁梁桥节点考虑腹杆弯矩、桥面板的竖向挠度以及对节点的影响的模型,进而进行非线性分析,从荷载-位移曲线、构件的塑性分布和破坏模式三个方面分析节点在复杂边界条件下的工作性能。模拟结果显示,节点的荷载-位移曲线饱满,屈服点不明显;构件的塑性分布与破坏模式与节点水平抗剪试验存在较大差异。桁腹式组合桁梁桥节点试验研究与参数分析。开展桁腹式组合桁梁桥节点试件在复杂边界条件下的反复加载试验,分析试件加载端的荷载-位移曲线、骨架曲线、构件应力和破坏形态。利用试验数据验证ABAQUS模拟的有效性,并进行复杂边界条件下节点的参数分析。试验、模拟结果表明,荷载-位移曲线强化现象、卸载刚度退化明显;腹杆偏心受力,应力集中在顶端;试件的裂缝集中在外包围混凝土上;外包围混凝土等级、穿孔钢筋直径和有无贯通钢筋对屈服强度的影响较小,极限强度和延性的影响较大。简支桁腹式组合桁梁桥剪力滞效应研究。通过ABAQUS有限元模拟简支桁腹式组合桁梁桥在自重下的工况,以节点为观察对象,在宽度和长度两个维度上量化分析桥面板的纵向正应力、剪力滞系数和有效宽度的规律。模拟结果显示,桥面板上同时存在剪力滞效应和负剪力滞效应,在节点处效应最严重,各节间中点效应很低;按规范计算的简支箱梁桥有效宽度与桁梁桥上有效宽度最大值相当,但与最小有效宽度差距甚大。
[Abstract]:Truss belt-type composite truss bridge has broad application prospect in practical engineering because of its good economy, stronger span ability and convenient building maintenance, and the joint of truss abdominal composite truss bridge is the key component of truss abdominal composite truss bridge. At present, the horizontal shear behavior of truss belt-type composite truss bridge is deeply understood. Considering the bending moment of web bar, the vertical deflection of deck slab and the mechanical behavior, plastic distribution and failure pattern of the joints, And the shear lag effect caused by discontinuous distribution of joints is not well understood. Through finite element simulation and experimental study, the mechanical behavior, plastic distribution and failure mode of the joints of truss composite truss bridges are deeply studied in this paper. The main contents of this paper are as follows: nonlinear finite element analysis of the joints of truss composite truss bridges with truss bellows. ABAQUS is used to establish the joints of truss composite truss bridges to consider the moment of web members. The model of the vertical deflection of the deck slab and its influence on the joints, then the nonlinear analysis is carried out, and the load-displacement curve is used. Three aspects of plastic distribution and failure mode of members are analyzed to analyze the performance of joints under complex boundary conditions. The simulation results show that the load-displacement curve of the joints is full and the yield point is not obvious. There is a great difference between the plastic distribution and failure mode of members and the horizontal shear test of joints. Experimental study and parameter analysis of joints of truss bellows composite truss bridges. Development of truss abdominal composite truss bridge joint specimens under complex boundary conditions. Repeated loading test, The load-displacement curve, skeleton curve, member stress and failure form of the loading end of the specimen are analyzed. The validity of the ABAQUS simulation is verified by the test data, and the parameter analysis of the node under the complex boundary condition is carried out. The experimental results show that, The load-displacement curve strengthening phenomenon, unloading stiffness degradation obviously; web eccentric force, stress concentration on the top; the cracks of the specimen concentrated on the concrete surrounded by the outside; the grade of the outer surrounding concrete, The diameter of perforated steel bar and the effect of perforated steel bar on yield strength are small. The influence of ultimate strength and ductility is great. The shear lag effect of simply supported truss abdominal composite truss bridge is studied. The ABAQUS finite element method is used to simulate the working condition of simply supported truss abdominal composite truss bridge under dead weight, and the node is taken as the observation object. The rules of longitudinal normal stress, shear lag coefficient and effective width of bridge deck are quantitatively analyzed in two dimensions of width and length. The simulation results show that both shear lag effect and negative shear lag effect exist on bridge deck slab, and the effect is the most serious at the joint. The effective width of the simply supported box girder bridge calculated according to the specifications is equivalent to the maximum effective width of the truss bridge, but the gap between the effective width and the minimum effective width is very large.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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