全钢Tin-T防屈曲支撑抗震性能研究

Seismic Performance of All-Steel Tin-T Buckling Restrained Brace

全钢管套管(tube in tube,Tin-T)防屈曲支撑是一种重量轻、制作简单、安装方便的新型支撑构件,利用有限元软件Abaqus,针对该新型支撑构件进行低周往复循环加载模拟分析。设计6组不同形式的支撑构件模型,其中有5组为Tin-T防屈曲支撑构件,1组为传统单管(Tube)支撑构件。研究不同形式支撑构件的内外管在层间位移比RSD为0.67%、1%、1.33%、2%的情况下,构件的应力应变、骨架曲线、滞回曲线、耗能等抗震性能的变化和影响。研究结果表明:1)Tin-T防屈曲支撑的抗震性能指标均明显好于传统支撑,尤其是内管的受压承载力平均比传统支撑Tube构件提高了109%;2)为减轻重量和便于观察内管的受力变化,在外方管两侧做部分开洞处理,开孔率的变化对支撑构件的承载力和耗能影响并不显著,增减幅度均在5%以内;3)Tin-T防屈曲支撑增加内管厚度,虽然能提高支撑构件的耗能(附加有效阻尼比仅提高了5%),但附加有效阻尼比与增加构件重量相比,材料利用率并没有达到较佳的性能比。因此,以增加内管厚度来提高防屈曲支撑构件的耗能并不是最佳选择。

All-steel tube in tube(Tin-T) buckling restrained brace is a new type of bracing member with light weight, simple manufacture and easy installation. The finite element software Abaqus is used to simulate the low-cycle reciprocating cyclic loading of this new bracing member. Six different groups of support members are designed,five of which are Tin-T buckling restrained braces and one group of conventional single-tube brace. The changes of seismic behavior of stress and strain,skeleton curve, hysteresis curve and energy consumption of inner and outer tubes in different forms of bracing members are studied when the story drift ratio RSD is 0. 67%, 1 %, 1. 33%,2%. The results show that: 1) the seismic performance indicators of Tin-T buckling-restrained braces are significantly better than those of traditional braces. In particular,the inner pressure bearing capacity of the inner tubes is on average 109% higher than that of the conventional support tube members. 2) To reduce weight and for convenience, the changes in the force of the inner tube are noticed,partial opening treatment is performed on both sides of the outer tube. The change of opening rate has no significant effect on the bearing capacity and energy consumption of the support members, and the increase or decrease range is only within 5%. 3) Tin-T buckling restrained brace increases the thickness of the inner tube, although the energy consumption of the support member can be increased (the additional effective damping ratio is only increased by 5%), but the additional effective damping ratio is compared with the increase of the weight of component,and the material utilization ratio does not reach a better performance ratio. Therefore, it is not a good choice to increase the inner tube thickness for enhancing energy consumption of buckling restrained brace.