罕遇地震作用下巨子型有控结构二阶效应影响分析

摘要

通过有限元分析软件sap2000建立了巨子型有控结构(MSCSS)的有限元模型,在考虑二阶效应的情况下,对MSCSS进行了罕遇地震作用下的弹塑性时程分析,并与不考虑二阶效应的结构地震响应情况进行比较,研究了二阶效应对塑性铰的生成、结构侧移以及杆件内力的影响.研究结果表明:选择不同地震波激励时,考虑二阶效应的作用会使塑性铰数量分布有不同的变化规律;第二子结构层间侧移受二阶效应的不利影响随楼层增加而增加,最大增幅达到6.4%,同时,巨型柱的弯矩和第二子结构梁弯矩均受到二阶效应不利影响,其最大增幅分别为7.2%和7.4%.因此在对MSCSS进行罕遇地震下的弹塑性响应情况分析时,必须考虑二阶效应对结果的影响.%The finite element software SAP2000 was employed to establish the finite element model of Mega-Sub Controlled Structure System ( MSCSS), and the elasto-plastic time history analysis considering the second-order effect of MSCSS under rare earthquake was carried out.The second-order effect on plastic hinge distribution, structural elasto-plastic story drift and structural internal force was analyzed by comparing with the structure without considering the second-order effect.The results show that: ( 1 ) the law of plastic hinge distribution considering the second-order effect is different when we choose different seismic wave excitation; (2)the second-order effect on story drift of second sub-structure is more and more adverse with the increase in floor and the most adverse effect is 6.4％; (3)the bending moment of mega column and second sub-structure beam is adversely affected by the secondorder effect, the maximum increase in the amplitude of bending moment is 7.2％ for mega column and 7.4％ for sub-structure beam.Therefore, the second-order effect must be considered when the MSCSS elasto-plastic response under rare earthquake is analyzed.