内置加劲环K型管节点抗冲击性能研究

为揭示内置加劲环K型钢管节点在冲击荷载作用下的抗冲击工作机理，采用高性能落锤冲击试验机进行了4个内置加劲环和1个未加强K型管节点的抗冲击性能试验，得到节点的破坏模态并分析了冲击力时程曲线。建立内置加劲环K型管节点有限元数值分析模型，与试验结果对比验证模型可靠性。分析加劲环几何参数对节点冲击性能指标的影响和冲击能量的耗散机理。研究结果表明:内置加劲环可以增强节点的刚度和强度，加劲环宽度和厚度的增加均使K型管节点抵抗冲击荷载的能力有所提高，且加劲环厚度增大对提高节点抗冲击性能的效果要强于宽度；加劲环先于主管耗能，随着加劲环耗能能力达到峰值，主管开始逐步耗能并成为主要耗能构件；设置加劲环可增大K型管节点的耗能能力，加劲环宽度、厚度越大，节点的耗能量越大，主管的耗能量越少。基于K型管节点在静力荷载作用下的承载力计算公式，通过数值模拟分析得出带有加劲环节点的动力放大系数R，提出内置加劲环K型管节点抗冲击承载力计算公式，并验证公式的有效性。

STUDY ON IMPACT PERFORMANCE OF K-TYPE TUBULAR JOINTS WITH STIFFENING INNER RINGS

To reveal the mechanism of impact resistance of an inner ring-stiffened tubular K-joint under impact loading, impact tests were carried on four inner ring-stiffened tubular K-joint specimens and one ordinary joint specimen by high performance drop-weight impact machine. The failure mode of the joint was obtained and time history curves were analyzed. The finite element numerical analysis model of inner ring-stiffened tubular K-joint was established and the reliability of the model is verified by comparison with the test data, and the influence of the stiffening ring geometric parameters on the impact resistance index of the joint and the impact energy dissipation mechanism are analyzed. Study results show that inner stiffening ring can improve the stiffness and strength of the joint, both the increase of stiffening ring width and of thickness can improve impact resistance of tubular K-joint, and the improvement of impact resistance of the joint caused by the increase of stiffening ring thickness is