足尺U型插板钢管连接节点承载力特性的试验研究

Experimental Study of Connection Node Load Bearing Performance of Steel Tubes Connected by Full Scale U-Shape Inserting Plate

U型插板连接的节点焊缝是影响连接强度的主要因素之一,而对于复杂的空间受力焊缝,采用规范的承载力计算公式计算可能会偏于不安全。通过4个足尺U型插板钢管连接节点承载力特性的试验,研究了U型插板连接的承载力-变形特性、失效及破坏模式,以及加载过程中连接典型部位的应变发展情况。结果表明:连接节点的破坏是由于压力作用下U型插板下侧的钢管应变发展较快,发生局部外鼓的屈曲失稳而引起。此外验证了U型插板连接焊缝计算节点的连接强度能够较好反映其强度特点。

U-shape insert plate＇ node welding beam quality is one of the major factors affecting connection strength.To welds subjected to complex spatial loads,however,results from canonical load bearing formulae might be unsafe.Through experimental study of load bearing performance of connection nodes of 4 steel tubes connected by full scale U-shape insert plates,the carrying capacity and deformation character,as well as failure and damage modes of the plates are studied.The stress development at representative connection parts is also investigated.Results show that the cause of connection node damage is that because the stress of tube underside of plate develops fast under compression,local buckling instability occurs.In addition,it is validated that node connection strength calculation based on weld can better reflect its characters.