为研究张拉整体结构的弹塑性静力特性，引入一种适用于求解大转动小应变的高效有限元算法——共旋坐标( CR) 法． 将空间杆单元的大位移分解为整体坐标系下的刚体位移和局部坐标系下的小变形，推导出了单元切线刚度矩阵的新表达式． 采用一种结合荷载增量策略和 Newton-Raphson 法的非线性有限元算法对一个四杆张拉整体结构单元体的几何非线性弹塑性特性进行了研究． 结果表明: 相比于传统的 TL 法和 UL 法，采用CR 法对张拉整体结构进行非线性静力特性分析具有更高的计算效率; 四杆单胞结构下层构件的刚度大于上层构件的刚度; 自应力系数的增大会导致四杆单胞结构变“硬”，且结构受压时的表现比受拉时更为明显; 相比于结构的弹塑性响应，自应力系数在结构的弹性响应中扮演着更重要的角色．

To investigate the static elasto-plastic properties of tensegrity structures，an efficient finite element me- thod—co-rotational ( CＲ) formulation，which is suitable to solve large rotation and small strain problems，was in- troduced． Large displacement of a space rod element was decomposed into a rigid body motion in the global coordi- nate system and a pure small deformation in the local coordinate system． A new form of tangent stiffness matrix was derived based on the proposed approach． An incremental-iterative solution strategy in conjunction with the Newton- Ｒaphson method was employed to study the geometrical nonlinear elasto-plastic properties of a quadruplex tensegrity unit． Ｒesearch results shows that the CＲ approach is computationally more efficient than the traditional TL and UL formulations． The rigidity of lower“fibers”is larger than that of upper“fibers”in the quadruplex unit． With the increase of the self-stress coefficient，the tensegrity unit becomes stiffer，and this is more obvious when the struc- ture is under compression than under tension． Compared with the elasto-plastic response of structure，the self-stress coefficient plays a more important role in elastic responses．