Conception d'une pale d'éolienne de grande envergure à l'aide de techniques d'optimisation structurale

Abstract

In an effort to reduce the amount of waste generated by the decommissioning of wind turbines, different projects are currently ongoing to try to build recyclable thermoplastic composite wind turbine blades. The objective of this project is to study new wind turbine blade structural design concepts, better suited for manufacturing of thermoplastic composite, by using structural optimization methods. First, the studied blade and wind turbine are defined and the loads on blades are computed according to the International Electrotechnical Commission IEC 61400-1 standard. Four critical load cases, representing situations to which a blade could be submitted, were identified : wind turbine in operation with a vertical extreme wind shear (vertical blade), wind turbine in operation with a horizontal extreme wind shear (horizontal blade) and two parked wind turbine situations when submitted to extreme wind speed (vertical and horizontal blade). The design process is divided into two steps. The first step is a topology optimization in which the objective is to maximize the stiffness of the structure when using a given amount of material. The design domain is defined as the inner volume of the blade. Results show that the optimal structure uses a load carrying spar and several webs. In the second step of the optimization process, sizing optimizations are performed on several models with different topologies (different webs and ribs configurations). The objective is to minimize the blade mass with constraints on stiffness, strength and stability. Results show that models with 2 m spaced ribs allow a slight mass reduction when compared against a classical blade structural design. This design is also believed to be well adapted to thermoplastic composite manufacturing processes, i.e. welded assembly of moderate size parts.

Date	1 Sept 2010
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Simon Joncas (Supervisor)