Combined method of super element and substructure for analysis of ILTDBS reticulated mega-structure with single-layer latticed shell substructures

For the cylindrical intersecting-latticed-three-dimensional-beams-system (ILTDBS) reticulated mega-structure with single-layer latticed shell substructures, which is an innovative super-long-span structure, the structural configuration is first introduced in this paper. And then to improve the calculation efficiency, a simplified analytical method of combining super element and substructure is presented and studied in detail. In this method the latticed three-dimensional beams (spatial truss) of the main structure are regarded as super element with three generalized nodes, and the substructures embedded in the large grids of the main structure are disposed by static condensation method, i.e. substructure method. The super element stiffness matrix and the stiffness contribution of the substructures to the whole structure are developed. Numerical example shows that the calculation time of the presented method decreases significantly in comparison with the conventional finite element method, and the comparatively accurate results are obtained. In addition, the substructures’ participation in bearing loads cooperatively with the main structure can also be considered in this method. So it is a good method with high efficiency and precision for analysis of the ILTDBS reticulated mega-structure with single-layer latticed shell substructures.