腹板摩擦式自定心预应力混凝土框架的长期性能研究

发布时间：2018-02-01 05:21

本文关键词： 自定心混凝土框架长期性能地震易损性时变特征　出处：《东南大学》2016年硕士论文　论文类型：学位论文

【摘要】：装配式钢筋混凝土框架结构具有生产速度快,现场施工简便、构件加工精度高、节约模板等优点,已得到广泛的重视和一定的应用。然而,传统装配式结构的节点连接可靠性较差,且会在震后出现较大的残余变形,给震后修复带来困难,因而在抗震设防区的使用受到限制。鉴于此,课题组此前提出了一种“腹板摩擦式自定心预应力混凝土框架”(以下简称自定心框架),以实现结构在震后的自动复位以及明确、可控的耗能；然而,现有研究尚未涉及自定心框架结构的长期性能,对于梁柱混凝土的徐变收缩、预应力损失及其对框架抗震性能的影响尚不明确。因此,本文围绕框架的有限元模拟、长期性能试验、抗震能力的时变特性等方面,进行了较系统的研究,主要研究工作及成果如下：(1)介绍了自定心混凝土框架节点的构造形式和主要力学性能特点。基于有限元分析软件DIANA,对自定心框架短期力学性能的数值模拟方法进行了研究,并利用柱底固结的自定心框架和混凝土现浇框架的低周反复加载试验结果,与数值模拟结果进行了对比,两者吻合较好,为自定心框架短期力学行为的模拟提供了可靠的工具。(2)自定心框架的长期性能试验及数值模拟研究。针对一榀单层单跨自定心框架,进行了超过一年的测试,测试内容包括框架各测点的位移、预应力损失。基于测试数据,对自定心框架的混凝土收缩徐变以及预应力损失情况进行了分析。在自定心框架短期行为数值模型的基础上,嵌入基于CEB-FIP90的混凝土收缩、徐变模型以及钢筋应力松弛模型,并考虑了配筋率等参数的影响,以描述自定心框架力学性能的长期变化。通过数值模拟结果与试验数据的对比,验证了所提出的数值模拟方法的可行性。(3)自定心框架地震易损性的时变特征研究。按坚硬土壤场地类型,选取20条远场地震记录,并进行IDA分析。以层间位移角和残余变形为指标,考察了结构在三种性能水准(IO、LS、CP)下的地震易损性及自定心能力。在此基础上,在不同时间点上分别进行IDA分析,研究了结构地震易损性随时间的变化特点。上述研究为自定心混凝土框架的长期性能和地震易损性研究提供了参考。
[Abstract]:The fabricated reinforced concrete frame structure has many advantages, such as high production speed, simple construction, high precision of component processing and saving formwork, etc., which has been widely paid attention to and applied to a certain extent. The joint connection reliability of traditional assembly structure is poor, and the residual deformation will appear after the earthquake, which brings difficulties to repair after the earthquake, so the use in the seismic fortification area is restricted. A kind of "web friction self-centring prestressed concrete frame" (hereinafter referred to as self-centering frame) has been put forward by the research group to realize the automatic reset of the structure after the earthquake and the explicit and controllable energy consumption. However, the existing research has not yet covered the long-term performance of self-centered frame structure, for Liang Zhu concrete creep shrinkage, prestressed loss and its impact on the seismic performance of the frame is not clear. This paper focuses on the finite element simulation of the frame, long-term performance tests, seismic capacity of time-varying characteristics, and so on, carried out a more systematic study. The main research work and results are as follows: 1) the structural form and main mechanical properties of self-centered concrete frame joints are introduced. Based on the finite element analysis software DIANA. The numerical simulation method for the short-term mechanical properties of self-centered frame is studied, and the results of low-cycle repeated loading test of self-centered frame and cast-in-place concrete frame are used. Compared with the numerical simulation results, the results agree well with each other. This paper provides a reliable tool for the simulation of short-term mechanical behavior of self-centring frame. The long-term performance test and numerical simulation of self-centering frame are studied. For a single-story single-span self-centering frame. After more than one year of testing, the contents of the test include the displacement of each measuring point of the frame, the loss of prestress, based on the test data. The shrinkage and creep of concrete and the loss of prestress of self-centered frame are analyzed. Based on the numerical model of short-term behavior of self-centered frame, concrete shrinkage based on CEB-FIP90 is embedded. Creep model and stress relaxation model of steel bar are taken into account in order to describe the long-term variation of mechanical properties of self-centered frame. The numerical simulation results are compared with the experimental data. The feasibility of the proposed numerical simulation method is verified. 3) the time-varying characteristics of seismic vulnerability of self-centered frame are studied. According to the site type of hard soil, 20 far-field seismic records are selected. The seismic vulnerability and self-centring ability of the structure under three kinds of performance leveling are investigated by using the interstory displacement angle and residual deformation as the indexes of IDA. On the basis of this, the seismic vulnerability and self-centering ability of the structure are investigated. The characteristics of structural seismic vulnerability with time are studied by IDA analysis at different time points, which provides a reference for the study of long-term performance and seismic vulnerability of self-centered concrete frame.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU378.4

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