细长结构几何非线性分析的子结构方法

将细长结构沿长度方向划分为多个子结构，并在每个子结构上建立一个随结构一起运动的连体基，则结构内任意点的位移可分解为连体基的转动和相对于连体基的小位移。利用细长结构这样的变形特征，本文详细讨论了连体基的转动，给出了与连体基选择方式相协调的节点位移及其虚变分表达式，并将子结构内部位移凝聚到了边界节点上。在此基础上，提出了一种细长结构几何非线性分析的子结构方法，可在不损失计算精度的前提下大幅度降低求解规模，从而提高了计算效率。数值算例验证了所提方法的有效性。

Substructure methods in geometric nonlinear analysis of slender structures

Along the longitudinal direction,a slender structure can be divided into several substructures on which an embedded coordinate frame is defined,there by total nodal displacements can be decomposed into the rotation of the frame and the small relative displacements with respect to the frame.Taking advantage of such deformation characteristics,we give the expressions of frame rotations and nodal displacements as well as their virtual variations,which are compatible with the definition of the embedded coordinate frames.Consequently,we presented a new substructure method for geometrically nonlinear analysis of slender structures,in which displacements of each substructure are reduced to the displacements of its boundary nodes.Compared to traditional methods of geometrically nonlinear analysis,the present method can greatly reduce the solution scale in case of not losing precision.Finally,an example shows the effectiveness of the method.