填充墙作用框架结构动力分析

Dynamic Analysis on the RC Frame Structure with Infilled Walls

目的为了解填充墙对框架结构振动周期、振动形态、动力反应等的影响特点,给结构设计提供参考和建议.方法建立了29个带填充墙的框架结构空间有限元对比分析模型,研究了结构的自振周期、振型特点,并且输入三种不同的地震波进行了时程分析.结果填充墙体对结构振动形态的影响不明显,但是当因减少填充墙体造成的"薄弱楼层"在建筑底部时,对结构的整体振动形态影响较大.随着填充材料刚度的减小,填充墙较少楼层处的刚度突变减弱,振型曲线更趋平滑;通过对比有限元方法和简化手算方法所得结构自振周期,认为考虑填充墙体影响时框架的自振周期折减系数取0.6较为合适;填充墙体的材料、位置、布置方式等对框架结构的动力时程反应均有一定影响.结论在进行框架结构填充墙体布置时应注意将其均匀分布于框架结构中,并尽量不在中部楼层设置过少的墙体;在结构计算时对填充墙框架自振周期应进行折减.

In order to know the influence of the infilled wall on the RC frame structure, and give some suggestions to the structure design,29 finite element analysis models of RC frame with infilled walls are established. The free-vibration periods and the vibration shape are studied. By putting 3 different earthquake waves into the RC frame calculate models, the time-history analysis are carried out. The analysis results indicate that the influence of the infilled walls on the structural vibration configuration is not obvious, but when the weak-floor caused by reduction of the infilled walls is at the bottom of construction,it has a greater impact on the overall vibration configuration of the structure. As the filler material stiffness decreases, the stiffness of floors with less infilled walls weakens suddenly and the vibration curve runs to be more smoothly. By comparing the self-vibration cycles of structure deriving from the finite element method with the simplified calculation method, we consider that the self-vibration period discount factor of 0. 6 is more appropriate when taking the influence of infilled walls into the RC framework. The material, location, layouts etc. of the infilled walls have a certain impact on the frame structure of the dynamic time-history response. During carrying out the wall layout we should pay attention to its even distribution in the framework and try not to set less walls at the middle floors.