脱空钢管混凝土受弯力学试验研究

发布时间：2018-04-03 02:33

本文选题：钢管混凝土　切入点：脱空　出处：《西南石油大学》2017年硕士论文

【摘要】：钢管混凝土因有强度高、重量轻、抗震性能突出、塑性和延性性能优异、施工方便快捷等优点,所以被广泛应用于房屋建筑和桥梁建设当中。钢管混凝土拱桥中主拱的T型节点是其关键位置,但主拱灌注的不密实、灌注完成后的混凝土收缩、成桥后的车辆疲劳荷载等都易引起钢管混凝土的脱空,严重影响了桥梁的安全性、耐久性和结构的稳定性。为此,本文通过试验方法研究了不同程度脱空对钢管混凝土受弯受力性能的影响,确保钢管混凝土结构的安全性。本文首先进行了脱空钢管混凝土受弯模型试验,针对10根受弯试件试验结果,分析脱空对试件的荷载挠度曲线、荷载—应变曲线、荷载—滑移曲线、核心混凝土受力性能等的影响,研究主管不同脱空程度对钢管混凝土的抗弯变形能力、承载力、应力应变分布等的变化规律。再通过有限元软件ABAQUS分别计算空钢管、钢管混凝土、脱空钢管混凝土的极限承载力以及其对应的荷载-挠度曲线,讨论了核心混凝土是否滑移对结果的影响,并分别建立了滑移模型与无滑移模型,得到在弹性阶段试件几乎不产生滑移或滑移量很小可以忽略的结果,并与试验结果进行对比,发现计算结果与试验结果吻合良好。利用等效截面法对脱空钢管混凝土的两个重要参数——抗弯承载力和组合弹性模量进行了具体分体,通过与已有结果进行对比,发现承载力计算结果误差在10%以内;给出了 5mm、15mm、25mm的脱空钢管混凝土相对于无脱空的钢管混凝土的抗弯刚度折减系数;总结了脱空钢管混凝土受弯过程中的力学性能,并提出了脱空钢管混凝土受弯的实用计算方法。本文对不同程度脱空的钢管混凝土受弯构件进行了系统的研究,并给出了相关的设计意见和建议,对脱空钢管混凝土受弯的理论研究有着重要的意义,也为工程设计和应用奠定了基础。
[Abstract]:Concrete filled steel tube (CFST) is widely used in building and bridge construction because of its advantages of high strength, light weight, outstanding seismic performance, excellent plasticity and ductility, convenient construction and so on.The T-joint of the main arch of CFST arch bridge is the key position, but the pouring of main arch is not dense, the concrete shrinkage after pouring, the fatigue load of vehicle after the completion of concrete-filled steel tube bridge, and so on, which can easily lead to the void of concrete-filled steel tube (CFST).It seriously affects the safety, durability and structural stability of the bridge.In order to ensure the safety of concrete-filled steel tubular structure, the effect of void removal on flexural behavior of concrete-filled steel tubular (CFST) is studied by means of experimental method.In this paper, the bending model test of concrete filled steel tubular (CFST) is first carried out, and the load deflection curve, load-strain curve and load-slip curve of 10 specimens are analyzed according to the test results of 10 specimens.The influence of the mechanical properties of the core concrete on the flexural deformation capacity, bearing capacity and stress-strain distribution of concrete filled steel tube (CFST) with different degree of void removal was studied.Then the ultimate bearing capacity and load-deflection curve of hollow steel tube, concrete filled steel tube and concrete filled steel tube are calculated by finite element software ABAQUS, and the influence of slip of core concrete on the result is discussed.The slip model and the non-slip model are established, and the results of little slip or little slip are obtained in the elastic stage. The results are compared with the experimental results, and the calculated results are in good agreement with the experimental results.By using the equivalent section method, two important parameters of concrete filled steel tube (CFST), the flexural bearing capacity and the composite elastic modulus, are divided concretely. By comparing with the existing results, it is found that the calculation error of the bearing capacity is less than 10%.The bending stiffness reduction coefficient of concrete filled steel tube (CFST) with 5mm or 15mm or 25mm is given, the bending stiffness reduction coefficient of concrete filled steel tube (CFST) is compared with that of concrete filled steel tube (CFST) without void, the mechanical properties of concrete filled steel tube (CFST) are summarized during the bending process, and the practical calculation method for bending of CFST is put forward.In this paper, the concrete filled steel tubular flexural members with different degree of voids are systematically studied, and the relevant design suggestions are given, which are of great significance to the theoretical study of the bending behavior of concrete filled filled steel tubular (CFST).It also lays a foundation for engineering design and application.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU398.9

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