Global stability design of grid cylindrical-lattice shells under combined axial compression and bending moment

Abstract

This paper focuses on the investigation into global stability design of grid cylindrical-lattice shell (GCLS) under combined axial compression and moments. This study is an extension of previous researches carried out by the authours in the elastic buckling and axially load-bearing capacity of GCLSs (Zhu et al., 2021, 2022). Accordingly the elastic buckling load and global compression stability coefficient of GCLS loaded axially are employed. The finite element model adopted in this study has been validated by previous researches (Zhu et al., 2021, 2022; Guo et al., 2017). First the elastic buckling behaviours of GCLS under pure bending moments is explored by using eigenvalue buckling analysis. The obtained results demonstrate the effects of the bending moment direction, the beam-column stiffness ratio, the diameter-height ratio of GCLS, the number of columns, and the number of storeys of GCLS on the elastic buckling load of GCLS. Subsequently, the ultimate stability capacity of GCLS under pure bending moment are investigated numerically by using a large number of numerical examples in the common range of engineering applications. Accordingly, a design formula is established based on a relationship between the bending stability coefficient φM and the compression normalized slenderness ratio λN, namely the φM-λN curve for predicting pure bending-bearing stability capacity. Finally, the interaction design formula for predicting the stability capacity of GCLS under combined axial compression and moment is proposed conservatively by introducing axial compression stability coefficient and bending moment stability coefficient. This interaction design formula is further validated by employing a large number of the numerical examples and provides fundamentals for designing GCLSs in practice.