FEM ANALYSIS FOR STIFFNESS OF HOLLOW SPHERICAL JOINTS

摘要

The joints' stiffness of space reticulated shell is an important influence factor on the stiffness and stability of reticulated shell, joints' fixation ability is of vital importance to maintaining the stability of reticulated shell. For complication of theoretical analysis and difficulty on experiments, the stiffness of hollow spherical joints which are applied widely in the large-span space reticulated structures, are analyzed and computed by finite element method with the SAP5 program in this paper, the expressions of axial flexibility function f and flexural stiffness ke of hollow spherical joints with parameters: joints' diameter and thickness, members' diameter are attained by regression analysis for calculation results. Here, orthogonal design and orthogonal quadratic multi-item formula are accepted by using orthogonal table L25 (56). These expressions can be adopted in the stiffness analysis and stability analysis of the large-span space reticulated structures with the hollow spherical joints considering the influence of joints' stiffness.