鞍板和环板加劲K形相贯节点承载力试验研究

为研究采用节点板、鞍板、环板加劲的K形相贯节点的受力特性，设计并制作了11个节点试件开展比例加载试验研究，得到其变形、应力分布及破坏模式等受力性能。利用经试验验证的有限元模型，分析了加劲组件和钢管参数对该类加劲相贯节点承载力的影响，并给出了受荷节点的力学模型。有限元分析和试验结果表明，该节点表现出无加劲相贯节点和带鞍板的管-板节点的受力特征，加劲构造能有效提高节点承载力。参数敏感性分析结果表明，增加支管和主管直径比、主管厚度、节点板长度和扇形鞍板圆心角可提高节点极限承载力。给出了极限承载力简化计算方法，计算结果和有限元分析及试验结果吻合较好。

Experimental study on bearing capacity of tubular K-joints stiffened with saddle plates and ring stiffeners

To gain insight into the mechanical characteristics of tubular K-joints stiffened with gusset plates, saddle plates and external ring stiffeners, a total of eleven specimens were designed and manufactured for the experimental study under proportional loading, and the mechanical properties including deformation, stress distribution and failure mode were obtained. Making use of the FE models which were validated by the experimental results, the effects of the parameters of the stiffeners and tubes on the bearing capacity of this kind of joints were analyzed, and a mechanical model of the joint subjected to the loadings was proposed. The FE analysis and experimental results indicate that the stiffened K-joints present not only the mechanical behavior of unstiffened tubular K-joints, but also the behavior of tube-gusset joints stiffened with saddle plates, and that the stiffeners are helpful in improving the bearing capacity of the joints efficiently. The results from the parametric sensitivity analysis show that the bearing capacity can be improved by increasing the ratio of brace diameter to chord diameter, thickness of chord, length of gusset, and center angle of sectoral saddle plate. Finally, simplified calculating equations for the bearing capacity were presented, and the results computed via the equations agree well with those obtained by the FE analysis and the experimental study.