半刚性组合框架骨架曲线实用计算方法

Simplified practical calculation method of skeleton curve of semi-rigid composite frame

针对组合节点的弯矩-转角计算模型以及组合框架骨架曲线计算模型忽略节点半刚性的问题,探讨组合节点转动刚度和半刚性组合框架骨架曲线的计算方法。基于参数相关性,运用改进的参数灵敏度分析方法,研究外加强环式钢管混凝土柱-钢梁节点的转动刚度。应用二阶分析推导柔性梁柱单元的刚度矩阵;应用得出的节点转动刚度计算模型推导半刚性组合框架骨架曲线的简化计算模型。研究结果表明:改进后的灵敏度分析方法得出的节点参数灵敏度更高。节点半刚性可降低骨架曲线的弹性刚度和下降段斜率。引入节点半刚性的骨架曲线计算模型更加符合组合框架的实际工作性能。

In view of the calculation model of moment-rotation for composite joints and the composite frame skeletoncurve model in which the semi-rigid of the joints is neglected, the calculation methods of the rotational stiffness of thejoint and the skeleton curve of the semi-rigid composite frame were investigated. Based on parameter correlation, theparameters sensitivity of outer strengthening ring joint of steel beam to concrete filled steel tubes （CFST） columnstiffness were studied by using improved sensitivity analysis method. The stiffness matrix of flexible beam columnelement was deduced. The calculation model of the moment-rotation curve of the joints was simplified and used todeduce the semi-rigid composite frame. The results show that the improved sensitivity analysis method is more accuratein obtaining the sensitivity of the joint parameters. The semi-rigid joints can decrease the elastic stiffness and slope of theskeleton curve. The skeleton curve model in which semi-rigid joints is introduced is more in line with the actual workingperformance of the composite frame.