承受循环轴力的支撑屈曲后承载力研究

Research on the brace post-buckling compressive resistance under cyclic axial loading

为探讨在罕遇地震下支撑屈曲后承载力的合理取值方法,根据支撑的滞回性能试验及有限元分析回归出支撑的屈曲后承载力计算公式,并与各国规范的计算值进行对比。结果表明:支撑的屈曲后承载力可按我国现行建筑抗震规范的规定或按本文建议的回归公式计算;鉴于在支撑倒V形或V形布置的中心支撑框架中,受压支撑达到屈曲后承载力时,与其对应的受拉支撑屈服后的抗拉承载力也有退化,根据分析对比,建议被撑梁上的竖向不平衡力按受拉支撑屈服承载力竖向分量的80%计算。

In order to investigate the reasonable calculation methods of the brace post-buckling compressive resistance under a severe earthquake,based on the hysteretic tests and finite element analysis,some formulas were regressed and compared with that calculated by the different codes.The results show that,the brace post-buckling compressive resistance can be calculated by the method pursuant to the GB50011 code or the equation regressed by this paper.Based on the phenomenon that when the post-buckling compressive resistance is reached for the compressive brace,the tension resistance is less than the yield resistance for the corresponding tensile brace in the inverted V or V-type braces,the vertical unbalance force on the braced beam induced by the tensile and compressive braces is suggested to be equal to 80 percent of the vertical component of the yield resistance of the tensile brace.