带BRB的高层钢框架梁柱节点的受力性能研究

发布时间：2019-04-09 12:26

【摘要】：钢结构具有良好的力学性能、经济性能和使用性能,因而被广泛地应用在大型公共建筑、民用建筑、工业设备、厂房、桥梁等领域。随着城市人口的日益密集,世界很多大城市的建筑逐步向高空发展。但是高层建筑由于其层数多的因素,结构的受力十分复杂,除了承受本身极大的自重和使用荷载外,还有来自水平方向的风荷载和地震荷载等侧向作用,而后者在高层建筑结构设计中占有很大的比重。钢框架-支撑体系通过框架体系与支撑体系共同作用形成双重抗侧力结构体系,能够较好的抵抗侧向荷载作用。传统的框架-支撑结构中支撑采用的是普通支撑,在承受较大轴压力作用时支撑会发生屈曲变形,严重时可导致整体结构发生失稳破坏。鉴于此,一种外部具有约束机制的新型支撑被研制出来,即屈曲约束支撑,并且被广泛地应用,这种屈曲约束支撑的出现解决了普通支撑受压屈曲的问题,由于支撑外部有约束构件的约束作用,所以具有较高的承载力和抗震性能。1994年的美国加州北岭地震和1995年的日本阪神地震发生后,调查钢结构的建筑物,发现破坏的地方均发生在梁柱节点区域,由此说明钢框架中的梁柱节点作为整个结构的核心部分,也是钢结构设计的关键因素之一,对其进行理论探讨和试验研究以及运用有限元软件进行数值模拟分析是非常有必要的。本文基于屈曲约束支撑的国内外研究现状以及屈曲约束支撑在高层钢框架中的应用,采用通用有限元软件ABAQUS,依托于高层钢框架算例设计,选取算例中一带屈曲约束支撑的梁柱节点,研究屈曲约束支撑分别在循环荷载和单调荷载的作用下对高层钢框架中梁柱节点的影响,在此基础上去掉屈曲约束支撑外部约束构件,使其成为普通支撑,在相同的荷载工况下对比研究普通支撑对梁柱节点的影响,以及两种支撑自身的受力过程。通过模型的模拟和数值分析,再针对带屈曲约束支撑的梁柱节点,对屈曲约束支撑内部构件的屈服强度、内芯的弹性模量、支撑与梁柱连接的节点板大小、节点板厚度、节点板上面外加劲肋的长度进行参数分析,对比这些参数的变化对梁柱节点抗震性能和承载能力的影响。研究表明：带屈曲约束支撑的梁柱节点与带普通支撑的梁柱节点相比有更好的承载力和抗震性能。针对带屈曲约束支撑的梁柱节点：(1)随着支撑内芯屈服强度和弹性模量的升高,节点板尺寸和厚度的增大以及面外加劲肋长度的增加,梁柱节点的承载力随之提高；(2)随着支撑内芯屈服强度和弹性模量的降低,节点板尺寸和厚度的增大以及面外加劲肋长度的增加,梁柱节点的滞回曲线更加饱满,拥有更好的抗震性能。
[Abstract]:Steel structures are widely used in the fields of large-scale public buildings, civil buildings, industrial equipment, factory buildings, bridges and so on because of their good mechanical properties, economic performance and service performance. With the increasing density of urban population, the buildings of many large cities in the world are gradually developing to high altitude. However, because of the large number of stories in high-rise buildings, the force of the structure is very complex. In addition to bearing its own great self-weight and service load, it also has lateral effects such as wind load and earthquake load from the horizontal direction. The latter occupies a large proportion in the structural design of high-rise buildings. The steel frame-bracing system can resist the lateral load well through the joint action of the frame system and the bracing system to form the double resisting lateral force structure system. In the traditional frame-bracing structure, ordinary bracing is adopted. Under the action of large axial pressure, the bracing will take place buckling deformation, which can lead to the instability and failure of the whole structure when it is serious. In view of this, a new type of bracing with external constraint mechanism has been developed, that is, buckling-constrained bracing, and has been widely used. The emergence of this kind of buckling-constrained brace solves the problem of buckling of ordinary braces under compression. Because the external bracing is constrained by the constrained members, it has high bearing capacity and seismic performance. After the North Ridge earthquake in California in 1994 and the Hanshin earthquake in Japan in 1995, the steel structure buildings were investigated. The results show that the Liang Zhu joint in the steel frame is the core part of the whole structure and is also one of the key factors in the design of the steel structure. It is very necessary to carry on the theoretical discussion and the experimental research and to use the finite element software to carry on the numerical simulation analysis. Based on the research status of buckling-constrained braces at home and abroad and the application of buckling-constrained braces in high-rise steel frames, the general finite element software ABAQUS, is used to design the examples of high-rise steel frames. Liang Zhu joints with buckling-constrained braces are selected to study the influence of buckling-constrained braces on Liang Zhu joints in high-rise steel frames under cyclic load and monotonic load, respectively. On the basis of this, the external constrained members of buckling-constrained braces are removed and made ordinary braces. Under the same load conditions, the influence of common braces on Liang Zhu joints and the stress process of two kinds of braces themselves are comparatively studied. Through the simulation and numerical analysis of the model, the yield strength, elastic modulus of the inner core, the size of the nodal plate connected with Liang Zhu, and the thickness of the nodal plate for the Liang Zhu joint with buckling constraint bracing are analyzed, and the yield strength of the inner member, the elastic modulus of the inner core, and the thickness of the nodal plate are studied. The influence of these parameters on the seismic performance and bearing capacity of Liang Zhu joint is analyzed by analyzing the length of the external stiffener on the joint plate. The results show that Liang Zhu joints with buckling constraints have better bearing capacity and seismic performance than Liang Zhu joints with ordinary braces. For Liang Zhu joints with buckling constraints: (1) the bearing capacity of Liang Zhu joints increases with the increase of the yield strength and elastic modulus of the inner core, the increase of the size and thickness of the nodal plate, and the increase of the length of the external stiffener; (2) with the decrease of the yield strength and elastic modulus of the inner core, the increase of the size and thickness of the nodal plate and the increase of the length of the external stiffener, the hysteretic curve of the Liang Zhu joint is fuller and has better seismic performance.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU973.13

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