Optimization of wind turbine towers by using a multivariate stochastic calculation method

Abstract

In order to improve the structural design of tubular and lattice towers for wind turbines, and in order to allow for detailed structural optimizations, a methodology is desirable which allows for quick and reliable considerations of the complex dynamic load situations. Whereat for the design of details for the machinery and the blade optimization time domain methods using multi-body-simulations are well established, their usage is often to extensive due to the needed level of detail to use them for an iterative tower design. Especially with regard to lattice towers, it is therefore desirable to investigate faster stochastic methods which focus on the overall dynamic behavior based on the probability of structural stresses within the tower construction.Lattice structures are difficult to optimize with respect to their shape and topology by manual methods. Therefore, the lattice has been formulated parametrically in order to allow for an automatic update of the geometrical appearance. Both, the positioning of nodes, bracings, trusses and the overall detailing of the lattice are part of the object oriented algorithm.Using both tools, an automatic structural optimization of the geometry of a lattice structure for an onshore wind turbine has been performed. The gained results of the optimized lattice tower are finally compared to a conventional tubular tower.