钢管混凝土斜交网格外筒-RC核心筒结构体系在罕遇地震作用下的弹塑性行为研究

Elastoplastic behavior analysis on concrete filled exterior steel tube diagrid-RC core wall structure system under rare earthquake

钢管混凝土斜交网格外筒-RC核心筒体系不仅实现了与建筑立面设计的高度统一,同时提供了较大的抗侧刚度,在超高层建筑设计中应用日益广泛。基于某工程实例、合理的材料本构和单元选择,利用ABAQUS软件建立该体系的有限元模型,进行罕遇地震作用下的弹塑性时程分析,获得了结构基底剪力、顶部位移等结构整体响应时程曲线和构件受力情况。通过分析内外筒基底剪力时程曲线讨论结构协同作用机制,结合构件受力情况讨论结构关键构件屈服顺序与外筒斜交构件的屈服路径。结果表明,该体系内筒与外筒共同承担基底剪力,整体呈现筒中筒结构体系的受力特征;构件屈服顺序为混凝土核心筒连梁、斜交网格外筒斜柱、混凝土核心筒墙肢;外筒构件的屈服顺序呈现由结构底部至顶部、由角部至中央的发展模式,体现了斜交网格空间三维体系的受力优点。

Concrete filled exterior steel tube diagrid-RC core wall system not only achieves a high degree of unity with the building facade design,but also provides large lateral stiffness,and is increasingly used in the design of super high-rise buildings.Based on an engineering example,reasonable material constitutive and element selection,the finite element model of the system was established by ABAQUS software,and the elastoplastic time history analysis under the action of rare earthquake was carried out,and the overall response time-history curve of the structure and the stress of the members such as the base shear force of the structure and the displacement at the top was obtained.The synergistic mechanism of the structure was discussed by analyzing the time-history curves of the base shear force of the inner and outer tubes,and the yield sequence of the key structural members and the yield path of the oblique members of the outer tube were discussed in combination with the stress conditions of the members.The results show that the inner tube and the outer tube share the base shear force which presents the mechanical characteristics of the tube-in-tube structure system.The yield sequency of members is coupling beam of the concrete core tube,the inclined column of the outer tube of the diagrid,the wall pier of the concrete core tube.The yield sequency of the outer tube member presents the development mode of the bottom to top and corner to center which reflects the mechanical advantages of the three-dimensional system in the diagrid.