高耸钢管塔K型结点极限承载力的试验研究与理论分析

EXPERIMENTAL STUDY AND THEORETICAL ANALYSIS OF ULTIMATE STRENGTH OF STEEL TUBULAR K-JOINTS OF TALL TOWERS

对某高耸钢管塔带连接板的K型结点进行足尺模型试验,探讨极限承载力情况下的破坏现象和破坏机理,采用圆环-母线梁分离模型,根据钢管能量理论和虚功原理,推导出三管轴力作用下带连接板K型钢管结点的极限承载力公式,发现极限承载力不仅与主管壁厚、管径、结点板长度相关,还与主管轴向压力密切相关,同时提出了钢管在组合外力作用下存在临界轴压系数的概念。为K型钢管结点极限承载力设计提供依据。

Full-scale tubular K-joints with tube-gusset plate connections are constructed and tested under static loads. The failure modes and failure mechanism are analyzed. Based on tubular energy theory and virtual work principle, using ring-generator separation model, this paper proposes the calculation method of the ultimate strength of the tube-gusset K-joint under three-axial load. It reveals that the ultimate strength of K-joints depends on tubular thickness, diameter, length of gusset, and main tubular stress. Moreover, for tall transmission tower, the concept of critical stress coefficient of K-joints under complex load is also proposed.