方型鸟嘴式T形方管节点的应力集中特性研究  

Study on stress concentration characteristics of square bird-beak square-hollow-section T-joints

作　　者：程斌[1] 钱沁[1] 

机构地区：[1]上海交通大学,上海200240

出　　处：《土木工程学报》2015年第5期1-10,共10页China Civil Engineering Journal

摘　　要：基于试验测试和有限元分析对方型鸟嘴式T形钢管节点在主管和支管轴力作用下的应力集中特性进行研究,得到热点区域的应力集中系数(SCF)大小及分布规律。结果表明:方型鸟嘴式节点的热点外推区应力分布符合二次变化规律,其主管应力集中高于支管,且最大SCF通常出现在热点Cr-F、Sa-A、Sa-C、Sa-D等位置。鸟嘴式节点在主管轴力作用下的SCF值通常较小,但在支管轴力作用下的应力集中显著,且SCF受几何无量纲参数β、2γ和τ的影响较大。进一步与传统正放式节点对比后发现,在几何尺寸相同的情况下,方型鸟嘴式节点的最大SCF普遍低于传统正放式节点,且β值越小这种降低幅度越明显;但当β>0.75时,鸟嘴式节点的SCF值可能高于正放式节点。Stress concentrations,including stress concentration factors( SCFs) as well as their distributions,of square bird-beak square hollow section( SHS) welded T-joints were investigated by experimental and numerical methods.Load cases of chord axial force and brace axial force were separately considered.Results show that stress variations within extrapolation zones of square bird-beak joints can be described as quadric functions.SCFs on the chord are usually greater than those on the brace,and the maximum SCF of bird-beak joints commonly emerge at four hot spots,i.e.,CrF,Sa-A,Sa-C,and Sa-D.Typically,stress concentrations of a bird-beak T-joint under chord axial force are not very significant,while the SCFs under brace axial force,whose values vary remarkably with varying non-dimensional parameters β,2γ,and τ,are fairly high.Comparisons between bird-beak and conventional joints show that,for same dimensions,square bird-beak joints can induce lower SCFs than conventional joints,and the SCF differences between them will be amplified when β is decreased.It should also be noted that the maximum SCF of a square bird-beak joint could be higher than that of the conventional joint when β is greater than 0.75.

关 键 词：方管 鸟嘴式节点 面内轴力 热点应力 应力集中系数 

分 类 号：TU392.3[建筑科学—结构工程]