正装结构非线性应力应变累加规律研究

基于有限位移理论的正装结构非线性分析理论对解决超大跨度、柔性结构的非线性计算有重大意义.文中探讨了正装结构非线性的分析特点,研究了其应变场与应力场的Kirchhoff应力张量与Lagrange应变张量的适用性,提出了正装结构非线性分析中应力场与应交场的累加规律,导出了拖动坐标法的虚功增量方程,以此对杆系结构非线性分析常用的CR法和UL列式进行了精度比较分析.文中研究成果可为正装结构的非线性分析提供理论指导.

Study on accumulation of nonlinear stress and strain for step by step constructing structure

Nonlinear analysis based on finite displacement theory is very significant for long-span or flexible structures which are construcuted step by step.The characters of step by step constructing structure are concluded firstly.Then the applicability of both Kirchhoff stress tensor and Lagrange strain tensor are studied to describe the stress and strain field of these structures.The accumulative rules of nonlinear stress and strain are deduced,and equation of incremental virtual work is derived as to method of co-rotational formulation(CR).Based on these researches,method of CR is explained from the view point of finite displacement theory and compared with the method of updated-largrain formulation(UL) in their calculation accuracy.The result of this paper can provide the theoretical instructions for nonlinear analysis of step by step constructing structures.