考虑下部结构屈曲约束支撑在双层柱面网壳中减震性能分析

发布时间：2018-06-20 01:01

本文选题：屈曲约束支撑 + 双层柱面网壳　；参考：《兰州理工大学》2013年硕士论文

【摘要】：随着大跨度空间结构的快速发展,有关网壳结构抗震性能的研究越来越受到关注。近几十年来,专家学者对结构的消能、减震做出了许多的工作,并且取得丰硕的成果,结构设计从此不再是单纯依靠增强梁、墙、柱的刚度来达到抵抗地震作用的目的,而是可以利用消能减震装置更有效地起到减小地震作用造成的破坏。屈曲约束支撑(BRBs)是一种可以有效避免支撑失稳的减震构件,它主要是由外围约束构件以及核心钢构件两部分构成,当轴向荷载作用在此支撑上时,屈曲约束支撑的核心部分受到拉、压力作用,均可以使支撑达到完全屈服,支撑屈服的过程就起到了耗能的作用,以此保护主体结构。但在当前,对于屈曲约束支撑减震研究及应用只限于在一般结构当中,而在大跨度空间结构中的减震性能的研究目前还是处于初步阶段。工程中由于单层网壳结构的稳定性问题尤为突出,随着新建结构跨度的不断增大,许多网壳结构工程都被设计成双层网壳。本文拟利用考虑下部混凝土结构的双层柱面网壳作为研究对象,探讨屈曲约束支撑在该结构中的适用性以及减震规律性。主要工作从以下几个方面进行： (1)利用有限元分析软件ANSYS,按照双层柱面网壳结构形式以及杆件连接规律编写程序,实现自动化建模。模型中假定网壳杆件及屈曲约束支撑杆件均为理想弹塑性模型,同时下部混凝土构件为符合双线性随动强化模型； (2)对考虑下部混凝土结构协同工作的双层柱面网壳进行静力、模态分析,依据静力以及模态分析结果得出结构变形特性、节点各向位移分布以及自振频率,并依此合理考虑屈曲约束支撑布置位置及数量； (3)动力时程分析,通过对结构输入三维地震波,得出关键节点各向位移减震规律以及杆件轴力减震规律,然后分析对比不同布置方式的减震规律,总结不同的布置方式对结构减震性能的影响； (4)对一实例模型分别采用不同种类地震波以及不同加速度峰值地震波,进行结构计算分析,比较减震效果之间的差异,并总结出相关规律。
[Abstract]:With the rapid development of large span space structures, more and more attention has been paid to the seismic behavior of latticed shell structures. In recent decades, experts and scholars have done a lot of work on the energy dissipation and shock absorption of structures, and have achieved fruitful results. From now on, structural design is no longer simply relying on strengthening the stiffness of beams, walls and columns to achieve the purpose of resisting earthquake. Instead, energy dissipation devices can be used to reduce the damage caused by earthquakes more effectively. Buckling restrained bracing (BRBs) is a kind of shock absorption member which can effectively avoid the instability of braces. It is mainly composed of external restrained members and core steel members. When the axial load is acting on the braces, When the core part of buckling restrained braces is pulled and subjected to pressure, the bracing can be completely subdued, and the process of bracing yield plays a role of energy dissipation, thus protecting the main structure. However, at present, the research and application of buckle-constrained braces are limited to general structures, but the study of seismic absorption performance in long-span spatial structures is still at a preliminary stage. In engineering, the stability of single-layer latticed shell structure is very serious. With the increasing span of new structure, many latticed shell structures are designed as double-layer latticed shells. In this paper, the applicability of buckling restrained braces in the structure and the regularity of vibration absorption are discussed by using the double-layer cylindrical reticulated shell with consideration of the lower concrete structure as the research object. The main work is as follows: 1) using finite element analysis software ANSYS, according to the structure form of double-layer cylindrical latticed shell and the rules of link connection, the automatic modeling is realized. In the model, it is assumed that the latticed shell member and buckling restrained bracing member are ideal elastic-plastic model, while the lower part of concrete member is in accordance with the bilinear follow-up strengthening model. (2) static and modal analysis of double-layer cylindrical reticulated shell considering the cooperative work of lower concrete structure is carried out. According to the results of static and modal analysis, the deformation characteristics of the structure, the displacement distribution in each direction of the node and the natural vibration frequency are obtained. According to this, the position and quantity of buckling restrained bracing are considered reasonably. The dynamic time history analysis, through the input of 3D seismic wave to the structure, the law of vibration absorption of every direction displacement of the key node and the law of the axial force damping of the member are obtained. Then it analyzes and compares the seismic absorption laws of different arrangement modes, summarizes the influence of different arrangement modes on the seismic absorption performance of the structure, and applies different kinds of seismic waves and different acceleration peak seismic waves to an example model. The structural calculation and analysis are carried out to compare the difference between the effect of shock absorption and to summarize the relevant laws.
【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】：TU33;TU352.1

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