防屈曲支撑在填充墙框架结构中的地震反应分析

发布时间：2018-05-13 15:04

本文选题：填充墙 + 框架结构　；参考：《西安建筑科技大学》2015年硕士论文

【摘要】：填充墙同框架间的协同工作对填充墙框架结构的抗震性能有非常大的影响。现行结构设计规范一般忽略填充墙对框架结构抗侧刚度的贡献,仅对纯框架进行周期折减来考虑填充墙对框架结构的作用。一些沿街的框架结构为了充分挖掘其商用价值,多将底部两层设计用于商业,上部楼层用作住宅或办公,因此其底部两层层高一般较高且几乎没有填充墙,而其他楼层层高小填充墙数量多,极易使底部楼层成为薄弱层,使结构遭遇地震时薄弱层率先发生破坏甚至倒塌,给结构的使用留下了安全隐患。为了研究填充墙对底部大空间框架结构抗震性能的影响及消除这种结构薄弱层的方法,本文具体做了如下工作:1)根据之前学者对填充墙提出的等效斜撑截面宽度计算公式,利用有限元软件SAP2000对底部两层大空间(无填充墙)其他楼层有填充墙的结构建立纯框架模型和填充墙-框架模型。通过对比上述两种模型的周期,得出该类结构周期折减系数的拟合曲线,为此类结构的周期折减系数提供参考。2)对底部两层大空间框架结构的周期折减框架模型与填充墙框架模型进行振型分解反应谱分析和时程分析,对比上述两种模型在边柱剪力、层间位移等方面的不同,找出现行规范设计方法存在的不合理之处。另外通过进行Pushover分析,比较此类结构两种模型的层间位移、结构塑性铰分布,发现存在的较大差异,以此说明底部楼层为薄弱层的框架结构要得到更准确的分析结果,应该建立填充墙框架模型进行分析。3)根据“刚度补偿”概念,提出了用防屈曲支撑消除结构薄弱层的简化设计方法及选择防屈曲支撑型号、数量的方法。以实际工程为背景,通过SAP2000有限元软件建立纯框架模型、填充墙框架模型、填充墙框架-支撑模型,进行了反应谱分析、模态分析、线性时程分析、非线性时程分析等,对比纯框架模型与填充墙框架模型的分析结果,发现两种模型在层间位移、顶点位移、顶点加速度、基底剪力、能量分布、滞回曲线等方面的差别很大,说明填充墙对框架结构地震响应有不可忽略的影响。通过填充墙框架-支撑模型与另两种模型上述结果的对比,发现多遇地震作用下防屈曲支撑能为结构提供抗侧刚度,罕遇地震下防屈曲支撑通过其滞回耗散地震能量,起到消能减振的效果,降低结构的地震响应、提高其抗震性能。验证了本文所述防屈曲支撑按“刚度补偿”原则消除结构薄弱层设计方法的正确性,说明防屈曲支撑对于消除结构薄弱层的设计及加固方面都有很好的应用价值。
[Abstract]:The synergistic work between the filled wall and the frame has a great influence on the seismic performance of the filled wall frame structure. The current structural design code generally neglects the contribution of the filling wall to the lateral stiffness of the frame structure. Only the pure frame is periodically reduced to consider the application of the filled wall to the frame structure. Some frame structures along the street are fully dug. To dig its commercial value, the bottom two layers are designed for business, and the upper floor is used as a residence or office. Therefore, the bottom two layers are generally high and almost no filling wall, and the number of filling walls in the other floors is very large, and the bottom floor is vulnerable to the weak layer, causing the weak layer to take the lead in destruction and even collapse when the structure is subjected to earthquake. In order to study the effects of the filling wall on the seismic performance of the large space frame structure at the bottom and the method of eliminating the weak structure, the following work is done in this paper: 1) according to the former scholar's calculation formula for the equivalent cross section width of the filled wall, using the finite element software SAP2000 to the bottom A pure frame model and a filled wall frame model are established in the structure of two layers of large space (no filled wall) with filled walls. By comparing the period of the above two models, the fitting curve of the period reduction coefficient of this kind of structure is obtained, which provides a reference.2 for the periodic reduction coefficient of this kind of structure to the cycle of the two storey large space frame structure at the bottom. The vibration mode decomposition response spectrum analysis and time history analysis are carried out between the reduced frame model and the filled wall frame model. The differences between the two models in the side column shear force and the interlayer displacement are compared, and the unreasonableness of the existing row standard design method is found. In addition, the interlayer displacement of the two models of this kind of structure is compared by Pushover analysis. The large difference in the distribution of the plastic hinge is found. It shows that the frame structure with the weak floor at the bottom floor should be more accurately analyzed. The frame model of the filled wall should be established to analyze the.3). According to the concept of "stiffness compensation", a simplified design method for eliminating the weak structure with buckling support and the selection of anti buckling are proposed. Based on the actual project, the pure frame model, the wall frame model, the filling wall frame support model, the response spectrum analysis, the modal analysis, the linear time history analysis and the nonlinear time history analysis are carried out, and the analysis results of the pure frame model and the filled wall frame model are compared with the actual project as the background. The frame model is filled with the wall frame model and the wall frame support model is filled with SAP2000. It is found that the two models have great differences in interlayer displacement, vertex displacement, vertex acceleration, base shear, energy distribution, hysteresis curve and so on. It shows that the filling wall has no negligible effect on the seismic response of the frame structure. The flexion support can provide anti lateral stiffness for the structure. In case of earthquake, the anti buckling support can dissipate the seismic energy through its hysteresis. It reduces the seismic response of the structure and improves its seismic performance. The correctness of the design method for eliminating the structural weak layer according to the "stiffness compensation" is verified in this paper. The buckling restrained brace has a good application value to eliminate the design and reinforcement of the weak structural layer.

【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398;TU311.3

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