Shahabeddin Torabian

Static Flexural Local Buckling Tests on Large Scale Spirally Welded Tubes for Use as Wind Turbine Towers

Taller, more economical wind turbine support towers are necessary for the future optimization of wind energy generation. Trends in current wind tower designs clearly demonstrate this need. Many large turbine manufacturers have begun production on large towers (taller than 120 m) that employee non-traditional wind turbine tower manufacturing techniques. Keystone Tower System’s (KTS) spiral welding manufacturing process for tapered steel towers is one example of a potential tall-tower manufacturing solution. Spiral welding is common in the pipeline industry where structural demands are influenced by internal pressurization. In contrast, the demand on wind turbine towers is dominated by flexural loading without internal pressurization. The lack of existing studies on the flexural behavior of spirally welded tubes is exacerbated by the high sensitivity to local buckling inherent in wind turbine towers, which have diameter-to-thickness ratios (D/t) that can exceed 300. For such structures, failure is dependent on initial geometric imperfections, including those induced by welding and other manufacturing procedures. Since spirally welded wind turbine towers will have a unique combination of welds, the impact of this particular manufacturing process on the ultimate local buckling strength of the towers must be understood. For this reason, a series of static, flexural tests have been undertaken on large scale spirally welded tubes. The preliminary results of these tests will be presented and discussed.

Modeling the Flexural Collapse of Thin-Walled Spirally Welded Tapered Tubes

AbstractThe objective of this study is to develop and validate a practical finite-element modeling protocol for predicting the flexural strength and collapse behavior of thin-walled spirally welded...