Design optimization of wind turbine tower with lattice‐tubular hybrid structure using particle swarm algorithm

As the size of wind turbine grows, the cost of the commonest tubular structural system will also increase because of the increasing cost of transportation, assembly, erection and servicing. A lattice‐tubular hybrid structural system, which is composed of a four‐angle cross‐shaped lattice structure at the bottom and a tubular structure at the top, is proposed for large wind turbine systems. The welding processes can be totally avoided and the fatigue strengths effectively improved because all members can be assembled by bolts in site after cutting and drilling in the factory. The ultimate bearing capacities of combined cross‐shaped members subjected to axial compressions are obtained by a series of numerical analyses. The column curve of four‐angle‐combined cross‐shaped members is obtained by fitting numerical results with a piecewise function. The particle swarm optimization algorithm is adopted to optimize the shape and size of the lattice partition in this study. The constraints including stress, slenderness ratio and frequency are applied to find the minimum weight of the lattice partition in the hybrid tower. The optimal results show that the proposed structural system is feasible and can resolve the disadvantages of the traditional tubular system in the fabricating, mounting and transporting. Copyright © 2016 John Wiley & Sons, Ltd.