新型全钢防屈曲支撑滞回性能的数值分析

Finite element analysis of the hysteretic behavior of new-type all-steel bucking-restrained brace

普通全钢防屈曲支撑(BRB)通常采用的一字形钢板作为内芯,在纵向容易出现局部屈曲,为此一种新型全钢BRB应运而生以缓解上述不利影响,该装置采用两块T型钢板作为次要约束构件,取代传统混凝土或砂浆在纵向对内芯的约束作用。为探究内芯初始缺陷、内芯与T型板之间的摩擦系数与间隙、内芯的宽厚比等因素对装置滞回性能影响,借助非线性有限元软件,对该新型全钢BRB展开数值模拟分析,通过模拟结果与试验结果的对比表明,该有限元模型能够很好重现全钢BRB的力学响应,建模方式可以作为全钢BRB参数化分析途径;通过上述相关因素的参数化分析表明,经过合理设计的新型全钢BRB可展现出诸多优势并具有良好的抗震性能。

Buckling-restrained brace(BRB)usually adopt a flat steel plate as the steel core.However,it tends to produce local buckling in the longitudinal direction.Therefore,a new type of all-steel BRB is proposed to alleviate this adverse effect,the device uses two T-shaped steel plates as auxiliary restraining members.To investigate the influence of factors such as the initial defect of the inner core,the friction coefficient and the gap between the steel core and the T-plate,the width-to-thickness ratio of the steel core on the hysteretic behavior of the device,the software of nonlinear finite element is used to simulate the new BRB.The results indicated that the finite element model could accurately reproduce the mechanical response of BRB,and this modeling could be used as a parameter analysis method for BRB.Meanwhile,the parametric analysis shows that the design of the new all-steel BRB exhibits distinguished seismic performance.