Effective utilization of unidirectional laminates for mass reduction in composite blades of multi-MW wind turbines

In this study, a reduction of 7.8–10.37% in the blade mass was achieved by optimizing the thickness of unidirectional spars in the Sandia 100-m all-glass baseline blade for a 13.2 MW wind turbine. The optimized design still complies with stiffness, strength, buckling, and resonance requirements for two design load conditions (i.e. DLCs 6.2 and 1.4) specified in the IEC 61,400-1 standard for both stationary and spinning blades. A genetic algorithm was utilized to solve the multi-criteria, multi-constraint optimization problem while satisfying the allowable design limits specified by the wind turbine standard. The optimized blade designs demonstrated effective use of unidirectional laminates in the spars but led to increased tip deflection and longitudinal strains along with a decrease in buckling performance and first natural frequency.