开槽式三重钢管防屈曲耗能支撑试验研究与有限元模拟

Experimental and finite-element studies of notched triple-steel tube buckling-resistant brace

依据"核心单元局部削弱相当于其他部位加强"的新型防屈曲耗能支撑设计原理,设计开槽式三重钢管防屈曲耗能支撑和普通三重钢管防屈曲耗能支撑,对其在轴向循环荷载作用下的滞回耗能性能、疲劳性能和破坏特征进行试验研究和数值模拟,并将试验研究结果与数值模拟结果进行对比分析。研究结果表明:开槽式三重钢管防屈曲耗能支撑在受拉和受压时都能屈服而不屈曲,其轴力-位移滞回曲线稳定、饱满,对称性和规律性好;开槽式支撑的屈服荷载和屈服位移小于不开槽支撑,具有提前屈服的功能,开槽不影响支撑的整体承载力,开槽式支撑的恢复力模型可以采用对称的双线性恢复力模型来描述;开槽可以使支撑的薄弱部位从核心钢管端部转移到开槽部位,使支撑具有定点屈服的功能,避免支撑端部破坏。

This paper presents a new design of notched triple-steel-tube buckling-resistant brace（TST-BRB）,based on the idea of ＂partially weakening the core element of the buckling-resistant brace to protect other parts of the brace member＂.This new design allows control of the yielding locations and the locations of plastic deformation initiation and propagation in the brace member,so as to dissipate seismic energy.Experimental investigations have been carried out to study the hysteretic energy dissipation,fatigue and failure characteristics of the buckling-resistant brace（BRB） members.Numerical analysis is carried out using the finite element software ABAQUS to study the hysteretic energy dissipation.The results indicate that the hysteretic curve of the proposed BRB is stable,full and symmetric.The yield displacement and yield stress of the non-notched specimen are larger than that of the notched specimens,with the bearing capacity of the BRB unaffected.The restoration force of the proposed BRB can be described by a bilinear model.Another advantage of introducing notches in the design of BRB is that it prevents the end elements from buckling so that it is not necessary to strengthen the ends of the core element of the BRB.Therefore,it substantially simplifies the fabrication process of BRB and also results in material savings.