铝合金内芯装配式屈曲约束支撑有限元分析

Finite Element Analysis of Aluminum Alloy Core Assembled Bucking-restrained Braces

提出了一种铝合金内芯装配式屈曲约束支撑(ALB),并以A5083铝合金为支撑耗能内芯设计了4组19个支撑构件,采用ABAQUS软件对其进行有限元分析,研究了集中耗能因子Y_(LR)、宽厚比、螺栓间距、核心板与约束板间间隙对支撑性能的影响。结果表明:当Y_(LR)<0.75时,支撑耗能性能会随着Y_(LR)的增加而提高,当Y_(LR)>0.75时,支撑耗能性能随着Y_(LR)的增加开始降低,当Y_(LR)=0.75时,支撑整体表现最佳;支撑耗能性能会随着宽厚比的增加而降低,宽厚比不超过10时,支撑可以获得更好的耗能能力;螺栓间距不宜过大,通过控制螺栓间距L_b与支撑核心板屈曲波长L_w的比值L_b/L_w来控制螺栓间距,当L_b/L_w≤1.5时,支撑约束单元受力更加合理,可以为核心单元提供足够的约束力;核心板与约束单元之间的间隙过小时无法为核心板变形留有足够空间,间隙过大时支撑承载力会有较大降低且不稳定,间隙控制在0.5～2 mm时支撑承载能力表现更佳。

An aluminum alloy inner core assembled buckling-restrained braces(ALB) was proposed, and four groups and nineteen kinds of ALB by using A5083 aluminum alloy as the inner core of energy dissipation were designed, and the finite element analysis was carried out by ABAQUS software. The influences of yield length ratio YLR, width-thickness ratio, bolt spacing, gap between core plate and restraint plate on ALB performance were studied. The results show that when YLR<0.75, the energy dissipation performance of the buckling-restrained brace(BRB) increases with the increase of YLR, when YLR>0.75, the energy dissipation performance of the BRB begins to decrease as the YLR increases, when YLR=0.75, the overall performance of the BRB is the best. The energy dissipation performance of the BRB decreases with the increase of the width-thickness ratio, when the width-thickness ratio is no more than 10, the BRB can get better energy dissipation capability. The bolt spacing should not be too large. The bolt spacing is controlled by controlling the ratio of the bolt spacing Lb to the buckling wavelength Lw of the BRB core plate. When the Lb/Lw is not more than 1.5, the force of the constraint unit is more reasonable and can provide sufficient binding force for the core unit. The gap between the core plate and the constraint unit is too small to leave enough space for the deformation of the core plate. When the gap is too large, the bearing capacity will be greatly reduced and unstable. When the gap is controlled in 0.5-2 mm, the supporting capacity performance is better.