全钢双芯板屈曲约束支撑的有限元分析

Finite Element Analysis of All-Steel Double-Core Buckling Restrained Braces

屈曲约束支撑是一种性能优良的减震构件,在小震及风荷载的作用下处于弹性状态,能为主体结构提供侧向刚度;在中震、大震及强震作用下,屈曲约束支撑能先于主体结构进入耗能状态。本文提出一种新型全钢双芯板屈曲约束支撑,设计了27个支撑试件,采用ABAQUS软件对各试件进行数值模拟,研究了内核单元与约束单元间隙、约束单元钢板厚度及加劲肋排布间距对支撑性能的影响。研究表明:过大的间隙会导致支撑承载力曲线波动幅度较大且承载力下降,为保证支撑的性能,支撑的间隙应取0.5~1 mm;不布置加劲肋的支撑试件随着约束单元钢板厚度加大,支撑滞回曲线的饱满度上升,而布置加劲肋可保证在约束钢板厚度较薄的情况下仍能获得饱满的滞回曲线,外套筒用钢量可节约30%以上;加劲肋的排布方式会影响支撑的滞回性能,当加劲肋布置在芯板耗能区域时可实现芯板在加载过程中全截面屈服,支撑表现出良好的耗能性能。

Buckling restraint bracing is a kind of shock absorber with good performance.Under the action ofsmall seismic and wind load,it is in elastic state and it can provide lateral stiffness for the major structure.Under the action of moderate earthquakes,major earthquakes and strong earthquakes,the buckling restraintbracing can get into consuming energy before the main structure.In this paper,a new type of all-steel doublecore plate buckling restraint bracing is proposed,27 specimens are designed,and numerical simulation of eachspecimen is carried out by using ABAQUS.The influences of the clearance between core element and restraintelement,the thickness of restraint element steel plate and the spacing of stiffener on the buckling restraintbracing are studied.The research shows that excessive clearance will lead to large fluctuation range of bearingcapacity curve and decrease of bearing capacity. In order to ensure the performance of the support,theclearance of the support should be 0.5~1 mm.With the increase of the thickness of the constraint unit steelplate,the fullness of the hysteresis curve of the support specimen without stiffener increases,while thearrangement of the stiffener can ensure that the full hysteresis curve can be obtained even though the thicknessof the constraint plate is relatively thin,and the steel amount of the outer sleeve can be saved by more than30%. The layout of the stiffener will affect the hysteresis performance of the support. When the stiffener isarranged in the core plate energy dissipation area,the full section yield of the core plate in the loading processcan be achieved,and the support shows good energy dissipation performance.