钢框架分析中考虑结点区变形的子结构法

Substructure Method Considering Panel Zone Deformation in the Steel Frame

对结点区的受力性能和剪切变形采用16结点相对自由度等参数壳单元进行分析,将相对自由度概念引入等参元,得到了16结点相对自由度壳元插值表达式,推导了单元刚度矩阵,在形成单元刚度矩阵时,引入材料的弹塑性性能考虑了结点区屈服对整体框架结构的影响.刚度矩阵形成以后对内部结点的自由度进行聚缩,采用子结构方法将出口参数转换为杆端自由度,使得结点区形成最多6个结点的空间组合单元体参与结构整体分析.在整体分析中,采用相对自由度壳单元考虑结点区剪切变形的非线性影响,可以同时考虑板件的局部屈曲.并通过算例证明了本文方法的精确度和有效性.

The shearing deformation and mechanical performance of panel zone were investigated through the 16 nodes isoparametric shell element with relative degrees-of-freedom. The concept of relative degrees-of-freedom was introduced into the isoparametric element, and the interpolation expressions of 16 nodes shell element with relative degrees-of-freedom were obtained. The element stiffness matrix was derived, and the effect of the panel zone yielding on the whole structure was considered by introducing material inelastic nature into the stiffness matrix. After the formation of substructure＇ s stiffness matrix, the degrees-of-freedom of internal nodes were condensed. The outlet parameters were converted to degrees-of-freedom of member ends by the substructure method, and the panel zone was formed to space element with 6 nodes at most to participate in the integral analysis. The nonlinear effects of panel zone were considered through shell element with relative degrees-of-freedom in the global analysis of steel frames, and the local buckling of plates could also be taken into account. The accuracy and the efficiency of the proposed analytical method were verified with numerical examples.