考虑二次受力影响的外包钢加固RC柱抗火性能研究

发布时间：2018-01-06 08:07

本文关键词：考虑二次受力影响的外包钢加固RC柱抗火性能研究　出处：《苏州科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：对于已建成的钢筋混凝土结构,由于建筑功能的改变,建筑物老化等原因导致结构安全性,适用性和耐久性不能满足要求,结构加固成为提高建筑物可靠性的重要手段。对于截面尺寸受限制的钢筋混凝土构件,外包钢加固是一种能大幅提高承载力的方法。目前,国内外开展了一些有关外包钢加固钢筋混凝土构件的力学性能研究,其抗火性能研究也日益引起重视。由于外包钢加固钢筋混凝土结构属于二次受力,这使其与未经加固的普通结构的受力性能有较大差别,因此在研究外包钢加固钢筋混凝土柱抗火性能时需考虑二次受力影响。针对以上情况,本文基于课题研究组进行的4根外包角钢加固钢筋混凝土柱的抗火性能试验数据,进行了考虑二次受力影响的有限元模拟分析。主要研究工作如下:(1)参考课题组试验数据和相关参考资料,选取合适的材料热力学性能和热工参数。(2)利用ABAQUS有限元软件建立了外包钢加固钢筋混凝土柱的有限元分析模型,在温度场分析时,考虑火灾下保护层砂浆爆裂和灌浆缝缓热作用,在热-力耦合分析时,考虑混凝土-角钢界面环氧树脂胶黏剂高温失效及汽化,但不考虑混凝土保护层的力学贡献。(3)在不考虑二次受力影响的条件下,取课题组完成的4根试验试件进行有限元模拟,将数值模拟得到的温度场和柱顶轴向位移曲线和试验数据进行对比,验证模型的合理性。(4)在验证模型的基础上,通过杀死激活单元和单元追踪来模拟二次受力的影响,通过加固前后荷载分配比n来表示第一次受力和第二次受力的分配情况,分析不同n值对外包钢加固RC柱变形和耐火极限的影响。(5)分析不同荷载比、偏心率、配筋率和角钢尺寸对二次受力下外包钢加固钢筋混凝土柱抗火性能的影响,重点考察了参数的变化对一次受力与二次受力耐火极限影响的区别,参考设计与工程实际,总结二次受力对外包钢加固钢筋混凝土柱抗火性能的不利影响,并提出有关抗火设计建议。
[Abstract]:For the reinforced concrete structure has been built, due to the building function change, building aging and other causes of structural safety, applicability and durability can not meet the requirements, become an important means to improve the reliability of the building structure reinforcement for reinforced concrete member section size restrictions, strengthened is a kind of method can greatly improve the bearing force. At present, domestic and foreign research on mechanical properties of some steel reinforced concrete member, the fire resistance research is increasingly paid attention to. Because the strengthened reinforced concrete structure is two times of stress, which makes it with the mechanical properties of ordinary structural reinforcement has great difference therefore, in the study of strengthened two impact force needs to consider the fire resistance of reinforced concrete columns. In view of the above situation, the 4 research groups based on Outsourcing Anti fire performance test data of reinforced concrete columns strengthened with angle steel, the finite element analysis of two stress impacts. The main work is as follows: (1) the reference group of test data and relevant reference materials, selection of thermodynamic properties and thermal parameters of the right. (2) a finite element of steel encased reinforced the analysis model of reinforced concrete columns using ABAQUS finite element software, the analysis of temperature field, thermal effect of corrosion seam mortar and grouting considering fire protection burst, the coupled thermal mechanical analysis, considering the concrete - steel interface epoxy glue adhesive failure in high temperature and evaporation, but do not consider the mechanics of concrete protective layer contribution. (3) without considering the influence of the two conditions, 4 test research group completed specimens are simulated by finite element numerical simulation of temperature field and the axial displacement curve and test data By contrast, verify the rationality of the model. (4) based on the model, by killing activation element and tracing to simulate the influence of the two force, the load distribution before and after reinforcement ratio n to represent the first time by the distribution of force and the second force, analysis the influence of different N value of foreign steel reinforcement the RC column deformation and fire resistance. (5) analysis of different load ratio, eccentricity ratio, reinforcement ratio and angle size of two times of stress under the effect of strengthened fire resistance of reinforced concrete columns, the changes were investigated on the parameters of a difference by force and the two force fireresistance effect design and engineering practice, summed up, strengthened with encased steel adversely affect fire resistance of reinforced concrete columns two times of stress, and puts forward relevant suggestions. The fire resistance design

【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU375.3

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