平面K型圆钢管搭接节点静力性能的试验研究

对平面K型圆钢管搭接节点的静力性能进行了静力单调加载的试验研究。实施了7个内隐蔽部分不焊接节点和3个内隐蔽部分焊接节点的试验。本文介绍了节点试验方案,考察了搭接节点的受力性能和破坏模式,并对内隐蔽部分焊接与否、焊脚尺寸、节点处集中荷载幅值以及腹杆搭接顺序对节点极限承载力的影响进行了讨论。试验研究结果表明,贯通腹杆受压时内隐蔽部分焊接与否虽然对节点的破坏模式和应力分布有一定的影响,但是对节点极限承载力影响较小;当腹杆与弦杆的壁厚相对值变小后,由于传力不均匀导致的腹杆局部破坏将成为主要破坏模式,而这一因素和所导致的承载力降低在既有的规范公式中尚未有相应的反映。

Experimental study on static behavior of unstiffened,overlapped CHS K-joints

To study the static behavior of unstiffened,overlapped circular hollow steel(CHS) K-joints,seven specimens with the hidden seam unwelded and three specimens with the hidden seam welded were tested under monotonic loading.The test procedure and joint failure mechanism are presented in this paper.The effects of the joint geometry,the throat thickness of fillet welds,with or without hidden seam welded,unbalanced loading at the joint as well as the loading hierarchy reversal on the joint behavior were studied.Results of these tests show that the welding situation of the hidden seam has some effects on the stress distribution and failure mechanism,but the static ultimate capacity of the overlapped CHS K-joints is not affected significantly given that through brace is under compression.When the brace-to-chord thickness ratio is smaller,the local failure is the main failure mechanism observed.This failure mechanism and the consequent reduction of the ultimate capacity have not been considered by the current codes.