Nonlinear stability of steel cooling towers with semirigid connections

Abstract Based on the experimental and numerical bending-rotation (M-Φ) curves of a new semirigid connection, the finite element model (FEM) of a semi-rigidly jointed reticulated steel (SJRS) cooling tower structure is established. Considering the connection stiffness (including rigid and semirigid), height, and mesh size, the dual nonlinear stability behavior of the SJRS cooling tower is analyzed. The complete load–displacement curves, buckling modes, and percentage of different connection statuses (linear, elastic–plastic, plastic, and unloading states) in the structure are obtained. Further, the influence rules of each parameter on the structural stability performance are analyzed in detail. Three main buckling modes, two local buckling modes (Mode-I and Mode-II), and one overall buckling mode (Mode-III) are obtained for the SJRS cooling towers with different connection stiffnesses. The results indicate the good carrying capacity of the steel cooling towers, and that the effect of bending stiffness on the stability of the SJRS cooling towers varies significantly with height, and the bending stiffness of the connection around the z-axis is the key factor affecting the critical load and buckling mode of the cooling towers.