摘要
本文通过理论简介和若干模型算例阐述了连梁单元类型对框筒结构整体刚度的影响。结构分析时连梁可采用杆单元或壳单元模拟,二者节点自由度不同。为改善杆-壳连接节点的转动协调性,结构分析软件普遍引入了带有转动自由度的壳单元模拟剪力墙。二维平面结构的计算分析表明,这种壳单元的转动自由度与杆单元不同,不能完全协调两种单元类型的转动,若不加以处理,结构刚度计算结果会偏柔,在单元尺寸较小时甚至会失真。本文提供了两种连梁处理措施来调整结构刚度,分别为在梁端增加伸入墙肢的刚性杆和设置双连梁,分析表明增加刚性杆的措施更为可靠。通过实际超高层框筒结构案例,验证了带转动自由度壳单元的局限性和连梁处理措施有效性同样适用于三维空间结构。最后,通过剪重比和框架剪力比等指标说明了不同连梁单元对普通框筒结构较明显影响,但对巨型框筒结构的影响则小很多。本文可为设计人员在框筒结构分析和设计时提供参考。
This article illustrated the influence of coupling-beam types on structural stiffness of frame-core tube structures by theoretical introduction and some calculation models.In structural analysis coupling beams could be established as frame or shell elements,which contain different Degrees of Freedom(DOF).To improve the rotating coordination of frame-to-shell joints,structural analysis software introduced shell elements with rotational DOF to model shear walls.Planar structural analysis showed that its rotational DOF is different from that of frame elements,which could not fully coordinate the rotation of frame-to-shell joints.The structural stiffness could be slender without taking measures,and even distorted when element size is small enough.In this article,two methods were suggested to fix stiffness of frame coupling-beam structures,including adding rigid bars into walls and introducing dual coupling beams.The former was shown to be more reliable.Analysis of super-tall frame-core tube structures indicated the limitation of shell elements with rotational DOF also exists in space models,as well as the validity of methods above.Finally,shear-gravity ratio and frame-shear ratio further indicated the influence of coupling-beam types on stiffness was significant for common frame-core tube structures,but much less for mega frame-core tube structures.This article could be referred to for analysis and design of this kind of structures.
作者
冯旭光
陈才华
陆宜倩
熊羽豪
程卫红
FENG Xuguang;CHEN Caihua;LU Yiqian;XIONG Yuhao;CHENG Weihong(CABR Technology Co.,Ltd.,Beijing 100013,China;National Engineering Research of Building Technology,Beijing 100013,China)
出处
《建筑结构》
CSCD
北大核心
2022年第S01期345-350,共6页
Building Structure
关键词
连梁
杆单元
壳单元
剪力墙
转动自由度
框筒结构
coupling beams
frame element
shell element
shear wall
rotational degree of freedom
frame-core tube structures
