空间足尺组合式连接节点受力性能研究

Study on mechanical behavior of multiplanar full-scale joint with composite connection

以某大型特高压用钢管格构式变电构架工程为背景,对空间足尺组合式连接节点进行空间静力加载试验和有限元分析,着重研究节点的应力应变及位移发展特征、破坏模式和极限承载性能。试验结果表明:设计荷载下,除主管与节点板连接处的端部由于应力集中而出现轻微局部屈服外,节点其他部位仍处于弹性阶段;加载至设计荷载的近190%时,主管受力较大端出现受压"鼓曲",主管与节点板1(JDB1)的连接处严重"凹陷",随即支管(7)的插板与JDB1连接处发生受压"失稳",节点破坏。有限元模型的分析结果,在节点应变发展、荷载-位移曲线、破坏模式、极限承载力等方面均与试验结果吻合较好。该类型节点的构造基本合理,满足设计荷载要求。建立节点承载力的理论分析模型及计算公式,理论计算结果与试验结果、有限元分析结果吻合较好。

The mechanical behaviors of multiplanar full-scale joints with composite connection, used in the UHV substation, were investigated by the monotonic loading tests and the finite element analysis （FEA）. Development characteristics of strain and displacement, failure mode and the ultimate load-bearing capacity of joints were mainly studied. Test results indicate that the end of the weld between the chord and the gusset plate locally yielded due to stress concentration under the design load, while the other parts of joints were still in the elastic stage. When the loads are close to 190% of the design load, serious local deformation appeared at the connection between the chord and the gusset plate, and the bulge deformation emerged at the end of the chord. After the instability occurred at the connection between the gusset plate 1 （JDB1） and the branch （~）, the joint failed. The FEA results of the strain development, load- displacement curves, failure mode and the ultimate loading capacity of the joint agree well with the test results, showing that the structure of the joint is reasonable, and the mechanical performance of the joint can meet the design requirements. The theoretical model and the loading capacity formula of the joint are established, and the theoretical results are in good agreement with the test results and the finite element analysis results.