摘要
为合理确定框架-核心筒柱的计算长度系数,基于周边各榀桁架协同工作机理,根据弱轴方向框架的屈曲荷载得到各柱的计算长度系数;进一步考虑核心筒对周边框架的支撑作用,通过增大系数对计算长度系数进行修正。在进行有限元分析时,采用在框架标准层顶部施加集中荷载的方法,所得到柱的计算长度系数在同一标准层内保持不变,与根据我国GB 50017—2017《钢结构设计标准》的计算结果保持一致。通过高度为60、90、120 m和150 m四个结构模型,考察结构高度、加载方式等因素对屈曲模态、屈曲荷载和柱计算长度系数的影响。分析结果表明:框架-核心筒结构的一阶屈曲模态均为弱轴方向的整体变形,柱未在框架平面外发生局部失稳的情况;根据层屈曲法得到外框架柱计算长度系数与按标准层加载有限元模型计算结果较为接近,两者误差为-9.59%~6.49%;框架-核心筒周边框架的屈曲荷载显著高于外框架分析模型的屈曲荷载;随着结构高度增大,周边框架屈曲荷载增幅逐渐降低;由简化方法得到周边框架柱的计算长度系数与按标准层加载有限元分析结果具有较好的一致性。
In order to determine the effective length factor of column within frame-corewall structures reasonably,the effective length factor of the column can be obtained based on the buckling load of the frame in the weak axis direction using the cooperative working mechanism of peripheral trusses.Further considering the supporting effect of the core on the surrounding frame,the calculated length coefficients were corrected by amplification factor.By applying a concentrated load on the top of standard floor of the frame structure,the calculated length coefficient remained unchanged within the same standard floor,which was consistent with the GB 50017—2017‘Design standard for steel structures’.The effects of structural height,loading mode and other factors on buckling mode,buckling load and effective length coefficient were investigated through four structural models with height of 60 m,90 m,120 m and 150 m.The results show that the first buckling mode of the frame-corewall models is the deformation in the weak axis direction,and no local instability of the columns occurs outside the frame plane.According to the story buckling method,the effective length coefficient of the frame column is close to that calculated by the standard story loading form within finite element model,with an error of-9.59%-6.49%.The buckling load of peripheral frame of frame-corewall structure is significantly higher than that of the peripheral frame analytical model,the increment of buckling load of peripheral frame decreases gradually with the increase of structure height.The effective length coefficient of the peripheral column obtained by the simplified method is in good agreement with the result of the finite element analysis based on the standard story loading form.
作者
范重
徐岳
牟在根
刘涛
韩文凯
吴浩
FAN Zhong;XU Yue;MU Zaigen;LIU Tao;HAN Wenkai;WU Hao(China Architecture Design and Research Group,Beijing 100044,China;School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2023年第S01期26-37,共12页
Journal of Building Structures
基金
中国建设科技集团中央研究院科技创新基金项目(Z2020C01)
关键词
框架-核心筒结构
屈曲荷载
计算长度系数
有限元分析
简化方法
frame-corewall structure
buckling load
effective length factor
finite element analysis
simplified method
