改进型混合式交错桁架钢结构体系抗震性能及破坏机理研究

发布时间：2018-05-11 09:01

本文选题：改进型混合式交错桁架体系 + 模型试验　；参考：《西安建筑科技大学》2013年博士论文

【摘要】：混合式交错桁架结构体系有较高的抗侧刚度和承载能力，因而具有良好的经济性能，同时在建筑布置上灵活多样，因而在结构工程领域得到广泛关注。但已有研究表明这种结构体系底部刚度较弱，易形成薄弱层而不利于抗震，鉴于此，本文提出增强底层刚度的改进型混合式交错桁架结构体系，并对其抗震性能和破坏机理进行研究。研究内容包括：（1）试验研究。依据现有规范，设计了1:3比例改进型混合式交错桁架钢结构试件，进行了低周往复加载试验，得到了结构顶层侧移与基底剪力之间的滞回曲线和骨架曲线，研究了循环荷载下结构的抗侧刚度、承载能力、耗能能力、延性变形、承载力与刚度退化能力以及结构的破坏机制。试验结果表明，结构的整体滞回曲线呈饱满的“梭形”，，耗能能力较好，具有良好的变形能力、较高的抗侧刚度和水平极限承载力。桁架斜腹杆的破坏大幅度降低了结构体系的抗侧刚度，使得交错桁架的承载力发生突降，需要对斜腹杆的非弹性变形能力进行严格要求。改进型交错桁架结构的薄弱层发生在结构中部，改善了传统交错桁架结构底部抗侧刚度不足的弱点，达到了改进的目的。（2）改进型结构形式整体性能参数分析。首先建立了改进型交错桁架的试件的有限元模型，对比分析了数值模拟结果与试验结果的破坏模式、承载力、刚度退化规律以及整体变形规律，验证了有限元模型的有效性；然后进行了改进型结构体系系统的参数分析。主要考虑了桁架跨度、桁架高度、桁架中间节间尺寸、桁架节间数等5个参数对改进型结构形式抗震性能的影响规律。（3）基于试验和有限元分析结果，提出了改进型交错桁架结构体系的抗震设计建议，包括桁架斜腹杆宽厚比值、桁架合理跨度和高度取值等方面的建议，供工程设计参考。
[Abstract]:The hybrid staggered truss structure system has high lateral stiffness and bearing capacity, so it has good economic performance, and is flexible and diverse in building layout, so it has been widely concerned in the field of structural engineering. However, previous studies have shown that the stiffness at the bottom of the structure system is weak, and it is easy to form a weak layer, which is not conducive to earthquake resistance. In view of this, an improved hybrid staggered truss structure system is proposed to enhance the stiffness of the bottom floor. The seismic performance and failure mechanism are studied. The research includes: 1) Experimental study. According to the existing codes, the 1:3 scale modified hybrid staggered truss steel structure specimens are designed, and the low-cycle reciprocating loading tests are carried out, and the hysteretic and skeleton curves between the lateral displacement of the top layer of the structure and the shear force of the base are obtained. The lateral stiffness, bearing capacity, energy dissipation capacity, ductile deformation, bearing capacity and stiffness degradation ability of the structure under cyclic loading and the failure mechanism of the structure are studied. The experimental results show that the hysteretic curve of the structure is full and fusiform, with good energy dissipation capacity, good deformation capacity, high lateral stiffness and horizontal ultimate bearing capacity. The failure of the inclined web bar of the truss reduces the lateral stiffness of the structure system greatly, and makes the bearing capacity of the staggered truss suddenly drop, so the inelastic deformation ability of the inclined web bar should be strictly required. The weak layer of the improved staggered truss structure occurs in the middle of the structure, which improves the weakness of the traditional staggered truss structure with insufficient lateral stiffness at the bottom, and achieves the purpose of improvement. 2) Analysis of the whole performance parameters of the improved structure form. Firstly, the finite element model of the improved staggered truss specimen is established, and the failure mode, bearing capacity, stiffness degradation law and integral deformation law of the numerical simulation results and the test results are compared and analyzed to verify the validity of the finite element model. Then the parameter analysis of the improved structure system is carried out. The influence of five parameters, such as truss span, truss height, truss Internode size and truss Internode number, on the seismic behavior of the improved structure is considered. Based on the results of test and finite element analysis, some suggestions for seismic design of the improved staggered truss structure system are put forward, including the ratio of the width to thickness of the truss inclined web bar, the reasonable span and height of the truss, and so on, which can be used as a reference for engineering design.
【学位授予单位】：西安建筑科技大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU391;TU352.11

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