Samenvatting

This research proposes new structural lay-outs for large wind turbine blades. The lay-outs were found by an optimisation method where the aerodynamics of wind turbine blades was combined with the structural model of the blade, formulated in a corotational framework. The aeroelastic blade loads were calculated using a Newton-Raphson root finding algorithm based on static equilibrium of the blade.
Then, using the properties of composite laminates, an optimum lay-up of the blade skin and spars was found using the gradient based optimisation algorithm global convergent method of moving asymptotes. The objective was minimum blade mass.
The lay-outs considered were a sandwich composite based blade where the sandwich skin also is applied for the spar caps and the second lay-out involves a classical stiffened skin concept, where the sandwich skin is replaced by a pure fibre laminate, including longitdinal stiffners.
It was found that he sandwich concept gives the lowest blade mass.