Influence of various types of node conectors on the buckling loads of grid shells

Abstract

Node connectors used in grid shells have various geometrical characteristics, which makes it difficult to compare them. Moreover, since free-form spatial structures have been introduced in the field of architecture, optimal connector design has become one of the crucial points for the stability of global structure. This paper presents the influence of various node connecting systems on the buckling loads of grid shells. The authors, at first, selected and investigated four connecting systems displaying different geometrical characteristics which are adapted in normal grid shells and free-form spatial structures. Using nonlinear beam elements with nonlinear spring elements in the commercial FEA package ANSYS, three-dimensional FE tests of node connectors were performed, taking into particular consideration the parameters of differing bolt clearances in the joint to estimate the ultimate loading capacities. The effects of moment-rotation and axial force were transferred to nonlinear spring elements on the grid shells. In conclusion, the results present the influence of bolt clearances of node connectors with geometrical imperfection on the buckling loads of grid shells.