Evaluation of buckling load of two-way single layer grid shells

摘要

The present paper proposes an effective method to evaluate elasto-plastic buckling loads of two-way single layer grid shells in the cases of either rigid or semi-rigid joint connections and either uniform or non-uniform vertical loads. The method is an extension to semi-rigid connection and non-uniform loads of a previously proposed method for fully rigid connections only. It utilizes a generalized slenderness ratio of a member that represents the buckling characteristics of not only individual members but also shell-like buckling. This slenderness ratio provides the column buckling strength of the member, and is used as a key measure of the buckling load of a grid shell. As a new development, it is extended herein to include the effects of different grid sub-divisions, shell geometries with different principal curvatures and the bending rigidity of the joints. Moreover, the applicability of the present method to either uniform or non-uniform loads is verified in this paper through comparison of the evaluated buckling loads with those obtained from FE elasto-plastic buckling analyses. Finally it is confirmed that the present procedure is valid and efficient enough to be applied in design practice.