Non-Linear Stability of Aluminum Alloy Single-Layer Reticulated Shells Considering Stressed-Skin Effect

The stressed-skin effect refers to the enhancement of skin stiffness on structural stiffness and the ultimate load. Accurately quantifying the magnitude of the stressed-skin effect is of great significance for the safety and economic benefits of structures. In existing research, the skin panels are usually modeled by shell elements rigidly connected to the members, which may have lower computational efficiency and are not consistent with actual construction practices. For the triangular skin panels in aluminum alloy single-layer spherical reticulated shells, this paper proposed a simplified calculation model based on multiple non-linear springs. This model can greatly reduce the number of elements and its reliability has been successfully validated. Through parametric analysis, it was observed that the skin stiffness is primarily determined by the thickness of the skin panels and the connection stiffness between the skin panels and the members. The simplified model was applied to the models of aluminum alloy single-layer spherical reticulated shells to explore the effects of skin stiffness and initial geometric imperfection on the ultimate load of the shells. The results show that considering skin stiffness can increase the ultimate load by 10–20%, while the adverse effects of initial geometric imperfection can be weakened. Based on extensive numerical results, the formula for the ultimate load of the aluminum alloy single-layer spherical reticulated shells was modified to consider the stressed-skin effect.