CCTV新台址主楼外筒“米”形节点滞回性能数值研究

Numerical studies of complex connections in the external tube system of New CCTV Building

在中央电视台(CCTV)新台址主楼外筒"米"形节点试验研究的基础上,建立了两种试验节点的有限元模型,分析了它们在反复荷载作用下的受力性能与破坏机理,并与试验结果进行了对比分析;数值分析中考察了支撑荷载偏心对节点承载力及滞回性能的影响;提出了考虑层间位移影响的框架-节点计算模型,研究了节点承载力及滞回性能。通过比较框架-节点模型的有限元计算结果与试验模型的试验结果,观察及评估了楼层层间位移对节点承载力及滞回性能的影响,其结论可用于对已有试验进行补充;研究了包含多个节点的双层框架有限元模型,考察了各节点在结构中共同受力时的承载性能及破坏模式,该分析将有助于综合评价结构外筒体系的抗侧承载性能。全面的有限元分析结果作为对节点试验的扩充,同样可以作为CCTV新台址主楼钢结构工程施工图审查及项目实施的依据。

Two kinds of finite element models of complex connections in the external tube system of New CCTV Building were investigated theoretically. Their strength state, seismic behavior and failure mechanism have been analyzed and estimated in accordance with the numerical results from finite element method. The effects of un-avoided brace eccentricities during loading process of test have been studied. An integral connection model was established which is composed of a loading frame with rigid beams and columns, a cross brace and a connection joint. The analytical objective of the integral model was to assess the additional effect of floor drift on connection behavior under cyclic loading, which hasn＇t been considered in advance in the early test. And the obtained numerical results can be used as the spread and supplementary parts of test. A two-floor structure from external tube of New CCTV Building which contains multiple complex connections has been analyzed under dead and cyclic load by using an elaborate finite element model. The conclusion drawn from the above numerical results and comparison between numerical and test results can be considered as the fundamental support and improvement to the design check and construction of New CCTV Building.