Numerical model, buckling analysis and ultimate load capacity of the single-double-layer reticulated dome

The advantages of two different structural types can be developed by combining the single layer spherical dome and the double layer square pyramid space grids. According to the different types of joints, three practicable numerical models are put forward, which are the pin-jointed model, rigid-jointed model and the rigid-pin-jointed model. The eigen-values and the eigen-vectors are analyzed using the Block Lanczos method with three different models. The equilibrium path is traced using the Cylindrical Arc Length Method. Based on the analysis of several factors including the single-layer-width-to-span ratio, the height-to-span ratio and the pipe types, the stability behaviors are summarized and the fitting formulae for critical load and ultimate load are obtained. The comparison between the simplified formula and the numerical analysis of an engineering project is given as well.