Research on the stress performance of lattice-type steel-tube-concrete ball-slab node four-limbed column wind turbine towers

Abstract

Two laboratory-scale steel tube and concrete four-leg lattice prototypes were designed for use as wind turbine towers using optimized gimbaled wrapped ball-sheet- type nodes. Repeated load tests were performed on the prototype tower for several weeks to evaluate its damage modes, strength, stiffness, etc., and the numerical simulation was conducted. The results showed that the damage mainly included strength damage to the pylon, flexural damage to the top cross web and cracks at the bottom of the loading plate welded to the steel pipe. In addition, the web-tower stiffness ratio and ultimate bearing capacity of the tower improved to varying degrees. It is recommended that the web-tower stiffness ratio be between 0.05 and 0.07. When the connection between the ball column and the node plate changes from a high-strength bolt connection to a welded connection, the ultimate load-carrying capacity of the tower model increases by an average of approximately 8%.

Keywords

• Wind turbine tower
• Low-circumference iterative test
• Ball-plate node
• Mechanical properties
• Finite element analysis