复合受力状态下矩形钢管相贯节点的承载力研究

Research on the load-carrying capacity of RHS joints with combined load cases

国家游泳中心的矩形钢管相贯节点,除双平面的几何特性外,同时承受轴力以及不可忽视的双向弯矩。本文的目的就是解决此类节点在这种特殊受力状态下的强度校核问题。研究工作以矩形钢管相贯节点在单项受力状态下的计算公式为基础,利用大量的有限元计算结果,回归得出T、TT、K、KT等4种类型节点在复合受力状态下———节点同时承受轴力、平面内弯矩、平面外弯矩中的两项或三项时的承载力计算公式。根据计算结果,本文还讨论分析了各类型节点的失效形态。研究表明,节点校核公式和破坏形态与节点的受力状态及节点的几何因素有关,如轴力的大小、弦杆截面高度及壁厚等。

The rectangular hollow section （RHS） welded joints of National Swimming Center are subjected to axial loads, inplane moments and out-of-plane moments from each brace simultaneously. In this paper, the research on the load-carrying capacity of RHS joints with such combined loads is presented. Based on the previous study of directly welded joints with individual loads and a large number of finite element analysis results, the joint capacity formulas are put forward with axial loads and moments in two planes interrelated. And the four planar and muhiplanar joint styles T type, TT type, K type and KT type, are included. The study indicated that the load-carrying capacity formulas and failure modes of each joint style were determined by the loads and joint geometry, such as the axial loads, the section height and the wall thickness of chord and so on.