某图书馆大跨转换桁架节点设计

Joint design of the long-span transit truss of the library

为实现建筑上"彩虹桥"的概念,本工程上部结构采用四榀大跨度桁架进行转换。在转换桁架根部以及主次桁架交汇位置,杆件数量较多,构造及受力复杂。节点设计上以"强节点、弱构件"为准则,构造上以传力合理、平顺,便于施工为导向。根据整体结构在多遇地震下的分析结果,选取两处关键节点位置,采用有限元分析软件MIDAS FEA对关键节点进行精细模拟。结果表明,节点设计满足既定的设计目标。

Four long-span transit trusses were used in the upper structure of the library,to realize the architectural concept of"rainbow-bridge".The upper structural system results in the complex joint-constructs and stress conditions of the transit trusses’roots and the intersections of the principal and secondary trusses,where many steel members converge.In terms of joint design,the principle is"strong joint and weak component",and in terms of construction,the force transfer should be reasonable,smooth and convenient for construction.Two key joints were chosen according to the analysis of the overall structure under the multiple earthquake.Fine simulation of the two key joints was performed with the aid of the finite element analysis software MIDAS FEA.The conclusions indicate that the constructs of the two joints meet the established design goal.