摘要
针对伸臂桁架斜腹杆在地震灾变过程中发生塑性屈曲,而宏观梁单元很难模拟塑性屈曲引起的承载力和刚度退化这一问题,以典型伸臂桁架试验为基础,在兼顾计算效率和精度的前提下,提出了基于梁单元和壳单元的伸臂桁架多尺度有限元模型;建立了典型超高层建筑的多尺度有限元模型,研究伸臂桁架塑性屈曲对地震灾变全过程的影响.结果表明,伸臂桁架多尺度模型能较好地预测初始刚度、屈服承载力以及塑性屈曲引起的承载力和刚度退化,且具有较高的分析效率;在进行超高层建筑地震灾变模拟时,不考虑伸臂桁架的塑性屈曲,会高估伸臂桁架的耗能能力,低估核心筒和巨柱的损伤程度,最终影响结构的倒塌模式并高估抗倒塌能力.
Plastic buckling of diagonal chords in outriggers has often been observed.The macro beam element has a limited capacity to simulate the strength and stiffness deterioration caused by plastic buckling.Based on the typical component seismic tests of outrigger,the multi-scale finite element(FE)model of outrigger combined with the beam and shell elements is proposed considering both accuracy and efficiency.And then the whole FE model of one typical super-tall building is built up with the proposed multi-scale model.Finally,the whole process of earthquake-induced collapse of super-tall building is discussed considering the plastic buckling of outriggers.The results indicate that the proposed multi-scale model of outrigger can accurately and efficiently predict the initial stiffness,yielding strength and the strength and stiffness deterioration caused by plastic buckling.During the earthquake-induced collapse simulation of super-tall building,the seismic energy dissipation capacity of outriggers will be overestimated and the damage of shear walls and mega-columns will be underestimated if the plastic buckling of outrigger is not considered.Consequently,these will affect the potential collapse mode and overestimate the collapse resistance of super-tall buildings.
作者
卢啸
吕泉林
徐龙河
李易
Lu Xiao;Lü Quanlin;Xu Longhe;Li Yi(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China)
出处
《天津大学学报(自然科学与工程技术版)》
EI
CSCD
北大核心
2018年第5期539-546,共8页
Journal of Tianjin University:Science and Technology
基金
国家自然科学基金资助项目(51408034)
中央高校基本科研业务费专项资金资助项目(2015RC057)
北京工业大学城市与工程安全减灾教育部重点实验室和工程抗震与结构诊治北京市重点实验室开放基金资助项目~~
关键词
超高层建筑
伸臂桁架
多尺度模型
地震灾变
塑性屈曲
super-tall buildings
outrigger
multi-scale model
earthquake-induced collapse
plastic buckling