CFRP钢管约束混凝土柱轴压承载力研究

发布时间：2018-03-28 23:43

本文选题：CFRP钢管约束混凝土　切入点：荷载-轴向位移曲线　出处：《大连海事大学》2017年硕士论文

【摘要】：CFRP钢管混凝土结构衍生于钢管混凝土的结构,指用碳纤维布缠绕黏贴于钢管混凝土外侧,形成以核心混凝土、钢管和CFRP为基础材料的组合结构,与传统钢管混凝土相比,由于CFRP的约束作用使结构具有更高的承载能力。综合钢管混凝土和CFRP的优点,此复合构件具有强度高、延性好、自重轻和抗锈蚀等优点。同时CFRP钢管约束混凝土良好的施工性能注定其在未来的工程应用上有着更广阔的前景。不同受荷载形式的结构力学影响差别巨大,就CFRP钢管混凝土柱体结构而言荷载多为两种形式,即(A式)轴压力由钢管和核心混凝土共同承担或(B式)仅作用于核心混凝土,关于前者的研究较多,本文重点讨论轴压荷载仅作用于核心混凝土(B式)的情况,因CFRP和钢管仅起到约束作用称之为"CFRP钢管约束混凝土"。在现有研究工作基础上本文分别以试验测试、理论分析和有限元数值模拟方法对CFRP钢管约束混凝土短柱的轴压力学性能进行深入研究。本文的主要研究内容如下:(1)本文做了 6组CFRP钢管约束混凝土短柱的B式轴压试验和2组A、B式轴压对比试验,每组3根试件,缠绕CFRP的层数分别为0、1、2层。观察24根试件并分析其破坏模态的异同,由短柱的材料参数、应变分析和荷载-轴向位移曲线分析了构件的破坏过程,研究了3种材料对轴向承载力提高系数和延性系数的影响。同时,通过A、B式对比试验分析了 B式加载方式的优势。(2)通过分析试验现象和破坏形态可知CFRP改善了核心混凝土中内力分布过程中的不稳定性,提高了试件的抗压能力和整体刚度。通过柱状图分析混凝土、钢管厚度和CFRP厚度对试件极限承载力的影响。以试验数据为基础,分别绘制CFRP钢管约束混凝土短柱在B式轴压加载方式下的承载力提高系数SI与径厚比D/t,钢管约束效应系数ls和CFRP约束效应系数lf的关系曲线和延性系数DI与ls和lf的关系曲线。分析曲线结果表明该结构承载力的提高主要取决于lf,而构件的延性同时受钢管和CFRP的双重影响。(3)通过对实验数据的线性归回和多元归回,得到构件承载力提高系数与套箍系数的关系模型,并通过模拟得出CFRP钢管约束混凝土短柱在不同混凝土强度条件下承载力的计算表达式;基于CFRP、钢管和核心混凝土在极限承载力时应力状态的合理假设,通过极限平衡法,推导出CFRP钢管约束混凝土短柱的B式轴压加载方式的极限承载力表达式。(4)为了弥补试验构件数量的不足,本文利用有限元软件ABAQUS对所有试验构件进行了模拟,分别对试件在受力过程中截面应力云图、环向位移、整体应力云图、材料参数和荷载-轴向位移曲线进行分析。
[Abstract]:The concrete filled steel tube (CFRP) structure is derived from the concrete filled steel tube (CFST) structure, which is wrapped in carbon fiber sheet and adhered to the outer side of CFST to form a composite structure based on core concrete, steel tube and CFRP, which is compared with the traditional CFST. Because of the constraint of CFRP, the structure has higher bearing capacity. Combined with the advantages of concrete filled steel tube and CFRP, the composite member has high strength and good ductility. At the same time, the good construction performance of CFRP steel tube confined concrete is bound to have a broader prospect in the future engineering application. As far as CFRP concrete filled steel tubular column structure is concerned, there are two kinds of loads, namely, A type) axial pressure is shared by steel tube and core concrete or B type only acts on the core concrete, and there are more researches on the former. This paper focuses on the case that the axial compression load acts only on the core concrete (form B), because the CFRP and the steel pipe only play a binding role, which is called "CFRP steel tube confined concrete". Based on the existing research work, this paper respectively uses the test test. Theoretical analysis and finite element numerical simulation method are used to study the axial compressive mechanical properties of CFRP steel tube confined concrete short columns. The main contents of this paper are as follows: 1) in this paper, six groups of CFRP steel tube confined concrete short columns are made. Type axial compression test and two groups of Agna B axial compression contrast test, In each group of 3 specimens, the number of layers winding CFRP is 0 / 1 / 2 respectively. Observing 24 specimens and analyzing the similarities and differences of their failure modes, the failure process of the member is analyzed by the material parameters, strain analysis and load-axial displacement curve of the short column. The influence of three kinds of materials on axial bearing capacity increasing coefficient and ductility coefficient is studied. The advantage of B type loading mode is analyzed by means of comparative test. (2) by analyzing the test phenomenon and failure form, we can see that CFRP can improve the instability in the process of internal force distribution in the core concrete. The influence of concrete, steel tube thickness and CFRP thickness on the ultimate bearing capacity of the specimen was analyzed by histogram. The relationship curves, ductility coefficient DI and ls and ductility coefficient of CFRP steel tube confined concrete short columns under B type axial compression loading were plotted respectively, and the relationship curves of the coefficient of constraint effect between steel tube and CFRP constraint coefficient L _ f and the coefficient of ductility coefficient DI and ls were drawn respectively. The results of the analysis show that the increase of the bearing capacity of the structure mainly depends on the LF, and the ductility of the members is affected by the double influence of steel pipe and CFRP. 3) through the linear regression and the multivariate regression of the experimental data, The model of the relationship between the increasing coefficient of bearing capacity and the coefficient of hoop is obtained, and the calculation expression of bearing capacity of CFRP steel tube confined concrete short column under different concrete strength is obtained by simulation. Based on the reasonable assumption of the stress state of steel tube and core concrete under the ultimate bearing capacity of CFRP, the ultimate equilibrium method is adopted. In order to make up for the shortage of test members, the finite element software ABAQUS is used to simulate all the test members. The stress cloud diagram of section, circumferential displacement, integral stress cloud diagram, material parameters and load-axial displacement curve were analyzed respectively.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU398.9

【相似文献】