The present study proposes an efficient scheme to estimate elastic-plastic buckling load of a shallow grid dome stiffened by diagonal braces. The dome is circular in plan. It is assumed to be subject to a uniform vertical load and to be supported by a substructure composed of columns
and anti-earthquake braces. Based on FEM parametric studies considering various configurations and degrees of local imperfections, a set of formulations are presented to estimate the elastic-plastic buckling load. In the scheme, the linear buckling load, elastic buckling load, and imperfection
sensitivity are first presented in terms of related parameters, and the elasticplastic buckling load is then estimated by a semi-empirical formula in terms of generalized slenderness ratio using a corresponding plastic load. For the plastic load, the present scheme adopts a procedure that
it is calculated by a linear elastic FEM analysis, while an alternative formula for the plastic load is also proposed based on a shell membrane theory. The validity of the estimation scheme is finally confirmed through comparison with the results based on FEM nonlinear analysis. The formulations
are so efficient and simple that the estimation may be conducted for preliminary design purposes almost with a calculator. .
