桁架式钢骨混凝土梁抗弯极限承载力计算及有限元分析

发布时间：2018-02-21 04:51

本文关键词： 桁架式钢骨混凝土梁抗弯极限承载力计算公式二次受力有限元分析　出处：《广西大学》2014年硕士论文　论文类型：学位论文

【摘要】：桁架式钢骨混凝土梁是将钢桁架整体焊接嵌入到混凝土中。与实腹式钢骨混凝土梁相比具有一定的优势。实腹式钢骨混凝土梁需要在型钢上布置栓钉来增强钢骨和混凝土之间的粘结力,而对于桁架式钢骨混凝土梁,因为钢桁架中的弦杆和腹杆增强了钢骨和混凝土之间的粘结作用,所以可以不用设置栓钉。钢桁架本身能够承受一定的荷载,因此当工程受到施工条件的限制无法搭设模板时,可以将模板直接支撑在钢桁架上,从而解决这一施工问题。本文主要作了以下几个方面的工作。1.本文通过有限元分析软件ABAQUS建立桁架式钢骨混凝土梁一次受力有限元模型。将有限元分析结果与课题组前期的试验进行对比以证明模拟的合理性。通过改变斜腹杆与下弦杆面积的比值讨论斜腹杆面积对桁架式钢骨混凝土梁抗弯极限承载力的影响。根据有限元分析结果引入腹杆面积增大系数。将修正后的公式计算结果与已有试验数据进行对比吻合度良好。2.推导桁架式钢骨混凝土梁二次受力抗弯极限承载力计算公式,通过所建立的公式讨论初始应力,配钢率,配筋率和截面高度对桁架式钢骨混凝土梁二次受力抗弯极限承载力的影响。计算结果表明二次受力抗弯极限承载力下降程度与初始应力,配钢率成正比。与配筋率和截面高度成反比。3.应用有限元分析软件ABAQUS中的单元钝化与激活技术建立桁架式钢骨混凝土梁二次受力有限元模型。通过有限元分析结果验证上文所建立的桁架式钢骨混凝土梁二次受力抗弯极限承载力计算公式的正确性。4.通过一个具体的工程示例对桁架式钢骨混凝土转换梁二次受力问题进行计算分析。
[Abstract]:Truss type steel reinforced concrete beam is a steel truss integral welding embedded in concrete. Compared with the solid web type steel reinforced concrete beam, it has some advantages. The solid web steel reinforced concrete beam needs to be bolted on the section steel to strengthen the steel bone. And the bond between concrete, And for truss steel-reinforced concrete beams, because the chords and webs in the steel truss enhance the bond between the steel and the concrete, you don't have to set a bolt. The steel truss itself can withstand a certain amount of load. Therefore, the formwork can be directly supported on the steel truss when the construction conditions limit the formwork. In order to solve this construction problem, this paper mainly does the following work. 1. The finite element model of truss steel-reinforced concrete beam is established by the finite element analysis software ABAQUS. The results of finite element analysis and the lesson are given. In order to prove the rationality of the simulation, the effect of the area of inclined web bar on the ultimate flexural bearing capacity of truss type steel reinforced concrete beam was discussed by changing the ratio of the area of inclined web bar to the area of lower chord. The results of the analysis are introduced into the increasing coefficient of web area. The calculated results of the modified formula are compared with the existing experimental data. 2. The formula for calculating the ultimate bearing capacity of truss steel-reinforced concrete beams under secondary loading is derived. Through the established formula, the initial stress and steel distribution rate are discussed. The effect of reinforcement ratio and section height on the ultimate bearing capacity of truss steel-reinforced concrete beams under secondary loading is studied. The ratio of steel distribution is directly proportional to the ratio of reinforcement and the height of section. 3. The element passivation and activation technique of finite element analysis software ABAQUS is used to establish the finite element model of truss steel reinforced concrete beam under secondary stress. The correctness of the formula for calculating the ultimate bearing capacity of truss steel-reinforced concrete beams under secondary loading is verified. 4. A concrete engineering example is used to calculate and analyze the secondary stress of truss steel-reinforced concrete transfer beams.
【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】：TU398.9

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