Structural assessment of a lattice tower for a small, multi-bladed wind turbine

Abstract

This paper deals with a limit load assessment and preliminary experimental testing of a lattice-type steel tower used to support a newly designed, prototype small wind turbine having nine blades and a rotor diameter of 3.4 m. Small wind turbine and structural engineering codes of standards were followed with the purpose of implementing a system that meets European Union countries' legislation. The supporting lattice tower structure was subjected to a full-scale load test. This test verified that the structure can withstand the design loads. The finite element software ANSYS Mechanical was used to model and analyse the actual structure, and to determine the possible failure modes and their associated load levels. The most probable mode of failure for such a structure was found to be elastic buckling of the main corner posts. A number of finite element lattice tower models utilising different modelling strategies and solution methods are presented and analysed. The paper highlights the importance of using non-linear analyses as opposed to linear analyses and gives recommendations on the most reliable available modelling technique. Computational analyses' results are compared with measurements from a full-scale test on the tower structure.

Observations on the construction methods used in Soviet-era shore navigational aids in the northern reaches of the Yenisei River

“…Due to this the towers were constructed as three-dimensional lattice rigid structures. Lattice towers are known to be very effective at withstanding both dynamic and static loads, notably those from the environment [8]. The greatest loads for the wooden towers in the Arctic are exerted by winds blowing across the open tundra and creating pressure on the dayboard.…”

Development and performance testing of a small, multi-bladed wind turbine

“…This structure underwent substantial structural modelling using FEA and additionally, non-destructive static load tests in the field so as to ascertain that it would be capable of supporting the new wind turbine under different operational conditions (Axisa, 2016). Results from this FEA analysis have been reported elsewhere and will not be dealt with further in the current work (Axisa et al, 2017). Meanwhile, the concept called for the design of an aerodynamically efficient multi-bladed rotor and a hub with an integrated braking mechanism coupled to an electrical generator by means of a drive train.…”

Trihedral lattice supports geometry optimization according to the stability criterion

“…Решетчатые башенные сооружения широко применяются в практике возведения стальных опор линий электропередач [1][2][3][4][5], опор ветрогенераторов [6][7][8][9][10], опор для размещения светосигнального оборудования [11]. При этом опоры с трехгранным поперечным сечением являются более экономичными, чем четырехгранные [12; 13].…”