K型外套强化矩管桁架节点滞回性能与恢复力模型

The Hysteretic Behavior and Restoring Force Model of the K-shape Outer Sleeve RHS Joints

为研究焊接外套强化K型矩管桁架节点滞回性能与恢复力模型,基于ADINA,采用引入微动力阻尼系数的非线性FullNewton-Raphson方法进行了节点滞回承载能力数值分析。考虑材料弹塑性、屈曲大变形、撕裂失效等非线性影响因素,得出了用以评价节点抗震性能的骨架曲线、延性系数等主要指标;结合外套管长度、厚度和支管与主管的宽度比等主要影响参数,分析了外套强化节点滞回性能的变化规律,进一步提出节点恢复力模型。研究表明,外套管加强节点的滞回性能提高明显,加大套管与主管的板厚比可以提高节点极限承载能力,基于此,给出了明确的加强套管设计构造参数,可供设计参考。

Based on ADINA program,numerical analysis was applied to study the hysteretic behavior of K-type welded outer sleeve RHS joints subjected to axially cyclic load,using the nonlinear method of Newton-Raphson with Low-Speed Dynamics Damping Factor.Considering the influencing factors such as elastic-plastic material,large deformation,and tearing failure,the skeleton curve and ductility coefficient were obtained,which were the main indexes reflecting RHS joints seismic behaviors.By changing the geometrical parameters of the outer sleeve joints（the length and thickness of the outer sleeves,the branch pipes to main pipes width ratio）,the variation regularity of the joints hysteretic behaviors was studied and the restoring force model was proposed.The analysis showed that the hysteretic behavior of K-type welded outer sleeve RHS joints is much better than that of the non-strengthen joints,and it can improve the ultimate capacity by raising the thickness ratio between the outer sleeve and the chord.