Abstract
Wind turbine tower structures composed of slender steel cylindrical shells mainly serve as primary load-bearing components and can be particularly susceptible to buckling due to their thin walls. Ensuring the structural safety of wind turbines therefore requires a clear understanding of the behavior of slender cylindrical shells, which is influenced by material properties, boundary conditions, and loading scenarios. This study experimentally investigates the structural responses of scaled cylindrical structures representing wind turbine towers beyond the proportional limit including the ultimate and post-ultimate strength depending on boundary conditions (fully and frictionally supported). Lateral loads were applied at the top of the specimens to simulate concentrated loads transferred from wind forces on the blades. Furthermore, a numerical model was developed to analyze the structural behavior of the tower validated against the experimental test results. The results provide valuable insights into optimizing the structural design of both onshore and offshore wind turbine towers, contributing to enhanced safety and performance under varying load conditions.