狗骨式钢框架子结构节点的累积变形及耗能能力

摘要

目的 研究在不同加载制度下狗骨式钢框架子结构中节点的累积塑性转角、累积延性比及累积耗能能力的计算方法,为钢框架结构基于性态的抗震设计理论提供参考.方法 基于所完成的6榀狗骨式钢框架子结构的拟静力试验,给出了钢框架子结构中典型狗骨式节点的滞回曲线,归纳了所有狗骨式节点的破坏模式、累积塑性转角、累积延性比及累积耗能能力,重点考察加载制度、板件宽厚比对其性能的影响.结果 钢梁板件宽厚比对钢框架子结构中狗骨式节点的显著屈服转角有一定影响,钢梁板件宽厚比越大,则狗骨式节点越易发生先屈曲后屈服现象.加载制度对钢框架子结构中狗骨式节点的累积塑性转角及累积耗能能力有显著影响,所施加的循环位移越小,其累积塑性转角及累积耗能能力越大.结论 通过统计分析回归了狗骨式节点的累积塑性转角、累积延性比及累积塑性耗能能力的计算公式,对提出狗骨式钢框架结构基于性态的抗震设计方法具有指导意义.%The approach for calculating the cumulative plastic rotation,cumulative ductility,and cumulative energy dissipation of reduced beam section(RBS) connections in steel frame under different loading protocol was investigated,which can provide some useful references for improving performance-based seismic design(PBSD) method of steel frame.Based on the previous cyclic tests of steel frame substructures with RBS connections,the hysteretic curves of typical RBS connections were proposed.The failure mode,cumulative plastic rotation,cumulative ductility,and cumulative energy dissipation of RBS connections were concluded.Additionally,the influences of loading protocol and width-to-thickness of steel plate were also compared.The analytical results show that the width-to-thickness of steel plate has a certain effect on the significant yielding rotation of RBS connection.With the increase of steel plate width-to-thickness,the RBS connection easily produces local buckling.The loading protocol has an important influence on the cumulative deformation capacity and cumulative energy dissipation capacity of RBS connection.With the decrease of controlled loading displacement,the cumulative plastic rotation and cumulative energy dissipation capacity of RBS connection show the increasing tendency.The calculating formula of cumulative plastic rotation,cumulative ductility,and cumulative energy dissipation of RBS connections were constructed through statistic analysis,which had guiding significance for the PBSD method of steel frame.