Similitude analysis of thin-walled composite I-beams for subcomponent testing of wind turbine blades

Abstract

In this study, the I-beam structure of a utility-scale blade is used as the basis for the design of a small-scale subcomponent emulating the same type of structural element of a utility-scale wind turbine blade. Governing equations for the bending of a shear deformable thin-walled composite I-beam are considered. Similitude theory is applied to derive the corresponding scaling laws. Accuracy of the derived scaling laws in predicting the strain and displacement fields of the full-scale I-beam is considered as a design criterion for small-scale I-beams. Both complete and partial similarity cases are discussed. A novel approach is proposed to design partially similar scaled I-beams with totally different layups from those of the full-scale I-beam. Using the proposed technique, scaled-down composite I-beams are designed that predict the strain and displacement fields of their full-scale parent I-beam with very good accuracy.

Investigating Core Gaps and the Development of Subcomponent Validation Methods for Wind Turbine Blades

“…Now researchers are directing efforts toward test development for filling in the gaps to reduce costs and streamline validation procedures. This may be in the form of spar cap/shear web I-beams [2], box spars, trailing edge failure validations [3], similitude analysis [4], or spanwise sectional validation [5]. Each of these techniques come with their own benefits and drawbacks.…”