钢筋混凝土框架梁弯矩调幅系数合理取值研究

发布时间：2018-06-05 01:41

本文选题：塑性内力重分布 + 弯矩调幅系数　；参考：《华中科技大学》2013年硕士论文

【摘要】：钢筋混凝土框架梁在荷载作用下，由于材料的非弹性变形、裂缝出现和开展，各截面的刚度在各受力阶段不断变化，这种刚度随荷载变化所引起的内力变化，一般称为钢筋混凝土框架梁的塑性内力重分布。钢筋混凝土框架梁关于塑性理论的计算方法有很多，目前应用最多的是弯矩调幅法。在弯矩调幅法中，塑性弯矩值是在弹性分析方法获得的弯矩值基础上，通过乘以弯矩调幅系数来对其进行调整而得到的。本文选取了梁截面高度、混凝土强度等级、钢筋强度等级、配筋率、活载与恒载比值（q g）五个参数对钢筋混凝土框架梁弯矩调幅系数的合理取值进行研究。本文首先建立了一系列单层两跨不同梁高、不同钢筋强度等级、不同混凝土强度等级的平面框架模型，采用PKPM软件进行设计计算，得出各调幅系数下梁截面的配筋；然后利用ANSYS有限元软件进行非线性有限元分析；最后，，分析计算得到的各调幅系数下截面的相对受压区高度、截面裂缝宽度、跨中挠度，判定调幅系数的合理取值。通过研究发现，调幅系数的合理取值范围为0.8~0.9；上述五个参数中，梁截面高度、钢筋强度等级、配筋率、活载与恒载比值（q g）对调幅系数取值影响较大，混凝土强度等级对调幅系数的取值影响较小。
[Abstract]:Due to the inelastic deformation of the material, the crack appears and develops, the stiffness of each section of the RC frame beam changes continuously during the loading stage, and the internal force changes with the change of the load. Generally known as reinforced concrete frame beam plastic internal force redistribution. There are many methods for calculating the plastic theory of reinforced concrete frame beams. In the moment amplitude modulation method, the plastic moment value is obtained by multiplying the moment modulation coefficient by multiplying the moment value obtained by the elastic analysis method. In this paper, the reasonable value of moment amplitude modulation coefficient of reinforced concrete frame beams is studied by selecting five parameters: section height, strength grade of concrete, grade of reinforcement strength, reinforcement ratio and ratio of live load to dead load (Q g). In this paper, a series of plane frame models with different height of single-story two-span beam, different grade of reinforcement strength and different grade of concrete strength are established. The design and calculation are carried out by using PKPM software, and the reinforcement of beam section under each amplitude modulation coefficient is obtained. Then the nonlinear finite element analysis is carried out by using ANSYS finite element software. Finally, the relative height of the section under the amplitude modulation coefficient, the width of the section crack, the deflection of the span in the middle, and the reasonable value of the amplitude modulation coefficient are determined by the analysis and calculation. It is found that the reasonable range of amplitude modulation coefficient is 0.80.0.Among the above five parameters, the height of beam section, the grade of reinforcement strength, the ratio of reinforcement, the ratio of live load to dead load (Q g) have great influence on the value of amplitude modulation coefficient. The strength grade of concrete has little effect on the amplitude modulation coefficient.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU375

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