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采用有限元分析软件SAP2000,在钢框架中分别布置普通支撑和屈曲约束支撑(下称BRB),模拟8度罕遇地震作用下结构的弹塑性时程反应,并对结构位移响应、层间延性需求、顶层加速度、基底剪力及塑性铰出铰顺序及分布进行分析。结果发现:BRB-钢框架体系两个方向最大层间位移角比普通支撑-钢框架体系分别小12.6%和17.5%,顶层位移峰值分别减小9.3%和19.4%;在允许延性需求为4.0时,BRB-钢框架体系和普通支撑-钢框架体系延性需求最大值分别为3.88和4.69;结构两个方向顶层加速度峰值分别减小27.6%和10.4%,基底剪力两个方向分别小了34.0%和26.3%;二者在地震作用下塑性铰初始出现时间差异不大,但塑性铰在BRB-钢框架构件中发展较慢,最终普通支撑-钢框架中部分节点和柱子完全丧失承载能力,而BRB-钢框架体系依然处于安全极限范围内。
The finite element analysis software SAP2000 is used to simulate the elasto-plastic time-history response of the structure under the effect of 8 degree rare earthquakes. The general support and buckling restraint brace (BRB) are arranged in the steel frame respectively. The displacement response, interlayer ductility Demand, top acceleration, base shear and hinge order and distribution of plastic hinges were analyzed. The results show that the maximum interlayer displacement angle in the two directions of BRB-steel frame system is 12.6% and 17.5% smaller than that of the common support-steel frame system, respectively, and the top displacement peak decreases 9.3% and 19.4% respectively. When the ductility requirement is 4.0 , The maximum ductility requirements of BRB-steel frame system and ordinary support-steel frame system are 3.88 and 4.69, respectively; the top acceleration peak in both directions of structure is reduced by 27.6% and 10.4% respectively, and the base shear force is 34.0% And 26.3% respectively. However, the difference of initial appearance time of plastic hinge under earthquake is not significant, but the plastic hinges develop more slowly in BRB-steel frame members. Finally, ordinary supports-some nodes and columns in steel frame completely lose their carrying capacity, The BRB-steel frame system is still within safe limits.