超高层结构伸臂桁架的承载力及刚度简化计算

对超高层结构体系中常用的伸臂桁架-单斜腹杆型式(N型)从桁架机制与刚架机制出发、依据伸臂桁架破坏模式建立了简化计算模型,揭示其受力机理.采用有限元模型对伸臂桁架的承载力和刚度指标进行了评估,得知斜腹杆是伸臂桁架主要的受力构件,对伸臂桁架整体承载力以及刚度均起着决定性作用.有限元计算值同简化模型计算结果较为接近,表明所提出的简化模型可以应用于伸臂桁架初步设计中的承载力及刚度的计算.

A Simplified Model on Strength and Stiffness of Outrigger Truss in Super High rise Structure

This paper investigates the performance of the outrigger truss with monoclinic web member (N type) through experiment and finite element analysis. A simplified model for the outrigger truss based on truss mechanism and frame mechanism is established. By the model, the mechanism of plastic resistance can be revealed. In addition, both the strength and stiffness of the outrigger truss can be obtained through numerical program. It is observed that among all the members, the diagonal web has the greatest impact on the strength and stiffness of outrigger. The calculation results of strength and stiffness index from FEM are close to that from the simplified calculation model, indicating that the proposed model and the calculation method can be applied to the preliminary design of outrigger truss.