阻尼比对混合结构地震影响系数的影响分析

Damping ratio analysis of the impact of the mixed structure seismic influence coefficient

大跨度混合结构在工程中应用广泛,一般由上部钢结构屋盖和下部混凝土结构共同组成。混合结构的抗震分析中,阻尼比的计算是否合理对于地震影响系数的大小具有关键作用。本文根据有限元理论,运用有限元软件Midas Gen对混合结构进行建模,建立了三种模型:综合阻尼比为0.04时模型1;综合阻尼比为0.03时模型2;运用组阻尼比分别求出各振型阻尼的模型3,并分别对三种模型进行计算分析。结果表明,采用组阻尼比不但可以准确的计算出各振型的阻尼比,使得对结构的地震分析更加精确,同时也可以作为对比数据,为采用综合阻尼比计算结构地震作用提供可靠依据。

Mixed structure is widely used in engineering, generally composed by the steel superstruc- ture roof and the lower part of the concrete structure. In the seismic analysis of the mixed structure, whether the calculation of the damping ratio is reasonable has a key role for the size of the earthquake affecting coefficient. According to the theory of finite element, three finite element models of mixed structure are established by Midas Gen in this paper： one model the integrated damping ratio is 0.04; the other is 0. 03; the third model use group damping ratio obtaining various modal damping and Then calculates analysis of the three models. The results show that the damping ratio using the group not only can accurately calculate the various modes damping ratio, the more accurate seismic analysis of structures, but also can be used as comparative data provide a reliable basis for the integrated damping ratio calculated earthquake effect.