空间相贯圆钢管节点受力性能试验研究与有限元分析

Experimental and numerical study on mechanical behavior of multi-planar steel tubular joint

以武汉天河机场T3航站楼为工程背景,对航站楼屋盖结构中典型空间相贯节点（X＋KT形节点）的静力性能进行了足尺试验研究和有限元分析。根据最不利设计荷载工况,对节点试件进行多点同步加载,得到了节点的受力性能、破坏模式和各杆件变形。根据试验节点实测尺寸建立非线性有限元分析模型,对试验节点进行数值模拟,计算结果与试验结果吻合良好。试验结果和有限元分析表明：试验节点具有较高的安全储备,其破坏模式为受压支管根部局部屈曲破坏。由于试验节点存在主管强、支管弱的特点,节点破坏不属于规范规定的主管过度塑性变形的破坏模式,因此规范中的承载力计算公式不再适用,运用有限元分析方法计算相贯节点承载力是一种有效的方法。

Based on the roof structure of T3 terminal in Wuhan Tianhe International Airport,the static behavior of multi-planar steel tubular joint（ X ＋ KT-joint） was studied by test and finite element analysis. According to the most unfavorable design condition,the multi-point synchronous loading of joint specimens was carried out. The bearing capacity,failure mode and deformation curves of the tested joint were obtained. By means of the measured geometric dimensions of the tested joint,finite element model was established to carry out the numerical simulation of test joints. The results show that the calculated results are consistent with the test results. The test and finite element analysis results observe that the tested tubular joint owns relatively high strength reserve,and its failure mode is local buckling of the end part of the compressive brace tube. Because of the characteristics of strong supervisor and weak branch line in test node,the joint damage does not belong to failure mode of superplastic deformation in the Chinese code. The formula of bearing capacity calculation in the specification is no longer applicable,and it is an effective method to calculate the bearing capacity of nodal intersections by using finite element analysis method.