黑龙江省新博物馆树状结构形态创建与稳定性分析

Form-finding and stability analysis of branching structures in new Heilongjiang Museum

树状结构是一种具有形态统一特征的新型空间结构形式,特别适用于展览馆、航站楼等大型公共建筑中。以黑龙江省新博物馆自然展区树状结构为例,详细介绍该结构的形态创建过程,通过对单柱方案和六柱方案的比较分析,获得了具有良好建筑效果且受力合理的空间结构形式;对该树状结构进行非线性全过程分析,考察结构的失稳模式,指出对于这种复杂空间刚架体系,整体稳定性分析应同时考虑几何非线性和材料非线性;探讨构件计算长度系数的确定方法,指出树状结构的杆件计算长度系数无法参照规范规定,而应通过对整体模型中的杆件失稳模态分析确定;最后,采用基于整体模型的屈曲分析方法给出各级分枝的计算长度系数取值建议。

Branching structure is a novel spatial structure type, which can be characterized as the harmony of form and force. Branching structures are very suitable for public buildings, such as exhibition halls or terminals. This paper takes the case of the new Heilongjiang Museum, which employs branching structures for the nature exhibition section. The form-finding and optimization process of branching structures are illustrated in detail. By the comparison of one- column case and six-column case, it could be seen that branching structures could make excellent effects in architectural and structural design, based on a flexible way in practical application. Then, the buckling modes and critical loading of the structure was investigated by full-range nonlinear analysis. It is indicated that the geometrical and material nonlinearity must be considered simultaneously when carrying out stability analysis for such complicated spatial rigid frames. The methods for calculating the effective length coefficients were discussed. It is indicated that the effective length coefficients of the members of branching structures cannot be determined by code method, but by the buckling mode of the overall structures. Finally, the effective length coefficients of branching structure were calculated based on the first global bucking mode and some suggestion values were given.