N型圆钢管相贯节点滞回性能有限元数值分析

相贯节点是钢管结构常用的节点形式，为评价普通及外贴钢板加强的N型圆钢管相贯节点的抗震性能，采用8节点实体单元分别建立两种节点的有限元模型，设置接触单元模拟加强铜板与节点主管之间的接触作用，对两种节点的滞回性能进行了有限元数值分析，得到两种节点在往复荷载作用下的滞回曲线、骨架曲线及节点域应力分布．两种节点的滞回曲线均呈有一定宽度的梭形，滞回性能良好；根据节点骨架曲线，外贴钢板使相贯节点极限承载力提高了25％以上．数值分析结果与相应试验结果基本一致，验证了有限元方法在相贯节点滞回性能研究中的适用性和可靠性．

Numerical Analysis on Hysteretic Behavior of Unstiffened Tubular N-Joints by Finite Element Method

Tubular joints are widely used in structures with circular hollow section members. In order to evaluate the seismic performance of unstiffened tubular N-joints and doubler plate reinforced tubular N-joints,the hysteretic behavior of the two joints under cyclic loads was studied numerically by the finite element method. Finite element models were set up for the two joints with 8-node solid elements and the interaction between the chord wall and the doubler plate was modeled with contact elements. Hysteretic curves,skeleton curves and the stress distributions around the intersections were obtained by the finite element analysis for the two joints respectively. Both the hysteretic curves of the two joints were of shuttle-shape with certain width, and their hysteretic behavior was good. The skeleton curves showed that the doubler plate increased the ulti- mate load carrying capacity of the unstiffened tubular N-joints by over 25%. All numerical analysis results agreed approxi- mately with the corresponding test results for both joints, which verifies the applicability and reliability of the finite element method in the study of hysteretic behavior of tubular joints.