Study on axial compression performance of curved steel-concrete-steel composite wall of wind turbine tower

Conventional steel towers typically use thin-walled steel tubes with diameter-to-thickness ratios far exceed general design requirements, resulting in low tower stiffness and susceptibility to local buckling under complex loads such as axial pressure and bending moment. This instability can lead to structural collapse, posing risks of casualties and significant economic losses. To improve the stability and economic performance of the tower, this paper proposes a steel-concrete-steel (SCS) composite tower including SCS tower section, tower flange nodes and connection of tower to foundation, and SCS composite tower section is composed of curved composite walls by the circumferential assembly. Seven axial compression specimens of curved SCS composite wall were tested to investigate the compressive behaviour , which focused on the effect of connector type, spacing-to-thickness ratio and connector arrangement. The outer steel plate had better stability compared to the inner steel plate due to the welded connectors. The spacing and thickness ratio directly affects the composite action of the steel plate and concrete. The specimens with staggered connectors had higher initial stiffness , which can help to limit the buckling of the steel plates. On the basis of the unified theory, the calculation methods of curved SCS composite wall specimens stiffness and axial compressive bearing capacity were proposed. Compared with the existing codes, the axial compressive load capacity calculation method proposed in this article considers the effects of steel plate buckling and steel-concrete composite interaction. Calculation results of the SCS composite tower showed that the method proposed in this study is proved more accurate, which can provide a theoretical basis for the future engineering design of SCS composite tower.