The Curvature – Energy Relations in Buckling Analysis of Tubular Wind Turbine Towers

A former study on wind turbine tower collapse incidences throughout the past 40 years revealed that among the various types the buckling failure was the most catastrophic as led to collapse of tubular tower shell structures. As the modern harvesting of wind energy is usually performed by wind turbine towers being cylindrical shells of thin walls, the need for thorough investigation of the buckling behaviour of shell structures operating under extreme environmental actions is obvious. The present paper addresses such knowledge gap through the study of a series of 100 numerical models underpinned by the well‐established Riks Method for buckling analysis. The method enables the scrutiny of tower shell elements under axial load and bending moment. Within the proposed framework of curvature–energy analysis, the energy stored within an imperfect shell structure is expressed and quantified through cross‐section diaphragms and symbolic lines, covering pre‐buckling, transient stage, and post‐buckling performance close to the bifurcation point. The analysis unveils changes of local surface curvature and energy flows with multiple longitudinal and circumferential wavenumbers taking place during the pre‐buckling process. Wavenumbers and curvature changes induce the energy magnitude jumping over to the adjacent buckling eigenmodes. Furthermore, the mode jumping sees a faster and more convergence result with higher bending moments. The diversity of the final buckling mode largely determined by the variance of shell geometry, compression–bending ratio and boundary conditions.