Stiffness properties of two-layer tensegrity axially spliced structure

Purpose - This study examines the stiffness properties of a two-layer tensegrity axially spliced structure consisting of two three-bar units under axial loading. Based on the tangential stiffness matrix, the deformation of the structure under different parameters is compared, and the primary influencing factors can be obtained. Design/methodology/approach - Initially, the mathematical model for the two-layer tensegrity axially spliced structure is established by defining generalized node coordinates and a connection matrix, followed by stability verification. Subsequently, an analysis of the tangential stiffness matrix identifies the primary factors influencing the stiffness of the two-layer tensegrity axially spliced structure. The unique splicing configuration of the two-layer tensegrity structure results in noticeable axial and radial deformations. Therefore, the impact of prestress, cross-sectional area, and Young's modulus on axial and radial displacements is investigated under axial loading conditions. Finally, the entropy weight method is employed to systematically determine the optimal prestress and component attribute parameters. Findings – (1) The method of forming a spliced structure by tensegrity units is feasible. (2) The axial splicing configuration leads to heterogeneous deformation responses across end faces. (3) The prestress, Young's modulus of strings, and cross-sectional area of strings notably influence structural stiffness. Originality/value - Through an examination of the stiffness characteristics of the two-layer tensegrity axially spliced structure, the optimal parameters are identified, offering valuable insights for the stiffness design of tensegrity structures utilizing unit splicing in engineering applications.