索管节点应力集中系数的足尺模型试验研究

Full-Size Testing to Determine Stress Concentration Factors of Dragline Tubular Joints

对4个索管节点进行足尺模型试验,确定索管节点的应力集中系数。在节点的内部和外部均安装了量表以测量焊缝脚部与根部的应力分布。在两种荷载下测量了应力集中系数,一种是沿着主索方向的拉、压力,另一种是垂直支撑上沿着斜撑反作用力方向上的拉、压力。提出了焊缝焊脚和焊根与相应应力集中系数的关系。用硅痕技术和接触式量表测量的焊缝形状和焊根缺口,为将来的有限元模拟以及采用有效切口应力方法研究焊根的破坏提供参考。

This paper describes the determination of stress concentration factors （SCFs） of dragline tubular joints through laboratory testing of four full-size dragline tubular joints. Strip gauges are installed both outside and inside the footprint of the joints to measure stress distribution at the weld toe and weld root. Measurements for SCF are carried out for two load cases, i.e. tension or compression forces in the main chord alone and tension or compression forces in the vertical bracings alone with reaction forces in the inclined braces. The relationship of the SCF between the corresponding weld toes and weld roots are presented in the paper. The weld profile and weld root gaps that have been measured using the silicon imprint technique and feeler gauges, provide valuable information for future FE simulation and weld root failure study using the effective notch stress approach.