In recent years, there has been a growing demand for renewable energy that is free of power generation by products to address the global climate and resource limitation crises. Wind power generation is maximizing efficiency through constant research and development, and as the use of large capacity turbines increases, the scale of supporting structure also increases. The structural maintenance of hollow towers, the supporting structure of wind turbines, requires the installation of an opening through which workers can access the tower to check corrosion, cracks, and damage to the tower body. However, these access points can affect the buckling strength of the tower structures due to section loss. In this study, the effects of the opening on the structural stability and ultimate strength of a large diameter cylindrical shell, which could be used as a wind turbine supporting tower structure, were studied through elastic buckling and nonlinear analyses. Based on the analytical results, the effects of the thickness of a collar stiffener around the opening on the structure’s ultimate strength were investigated. The results were compared to the design criteria, and through regression analysis, an effective equation to determine the collar stiffener’s thickness for large diameter cylindrical shells was proposed based on an opening that satisfied the design strength criteria.
Bibliographical noteFunding Information:
Funding: This research was funded by the Pohang Iron and Steel Co., Ltd. (POSCO). This research was also funded by the National Research Foundation of Korea (NRF).
Acknowledgments: This research was conducted by the research project POSCO (Code 2020Z032). This work was also supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. NRF-2021R1A5A1032433).
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Collar stiffener
- Geometric and material nonlinear analysis
- Large diameter cylindrical shell
- Linear buckling analysis
- Maintenance opening
- Optimal design
- Wind turbine tower
ASJC Scopus subject areas
- General Materials Science
- Metals and Alloys