薄钢板剪力墙结构边框架柱的设计方法研究

现行设计规范将钢板剪力墙结构边框架柱按压弯构件进行设计,并对其截面惯性矩进行了限制,该文首先介绍了钢板剪力墙结构挠曲系数及其边框架柱截面惯性矩限值的推演过程,然后通过理论分析和有限元计算研究了钢板剪力墙结构边框架柱的剪切承载力和面外稳定性,结果表明,边框架柱面内弯曲刚度不足或其剪切承载力不足,会导致钢板剪力墙结构出现“内凹”变形,影响墙板斜向对角拉力带的开展,因此,应按该文建议的方法对边框架柱的剪力设计值进行验算,避免边框架柱剪切屈服;现行设计规范对钢板剪力墙结构边框架柱截面惯性矩的限制,但未对边框架柱的面外稳定性提出要求,因此,应参照该文提供的方法,对钢板剪力墙结构的边框架柱进行面外屈曲的验算,保证其面外稳定性。

STUDY OF DESIGN PROCEDURES FOR VERTICAL BOUNDARY ELEMENTS IN THIN STEEL PLATE SHEAR WALLS

According to the current design codes, such as the 2005 AISC Seismic Provisions for Structural Steel Buildings, the vertical boundary elements (VBE’s) of steel plate shear walls (SPSW’s) are sized as beam-column members and the codes require a minimum moment of inertia for VBE’s to avoid “pull-in” behavior. This paper reviews the derivation of the flexibility factor, ω_t, and how the factor was incorporated into current code design requirements for SPSW’s. Then, analytical models to prevent VBE shear yielding and to estimate the elastic out-of-plane buckling strength of VBE’s are developed by theoretical analysis and finite element calculation. It is shown that the existing limit by codes on ω_t does not correlate with satisfactory out-of-plane VBE performance. The significant inward VBE inelastic deformation and out-of-plane buckling were due to excessive VBE flexibility or other causes, such as shear yielding at the ends of the VBE’s. Therefore, the VBE’s of SPSW’s should be designed according the proposed approach to avoid the VBE shear yielding and ensure out-of-plane stability.