Analysis of the effect of defects for fatigue life of composite wind turbine blades using FEM data

Abstract

One of the main global engineering challenges for wind energy sector is to develop efficient wind turbine blades with high fatigue life. Large wind turbine blades made out of polymer composites to delivering high specific stiffness and strength, and good fatigue performance. The arbitrary nature of wind flow and extreme weather conditions render wind turbine blades as fatigue critical elements. Therefore, reliable fatigue damage models need to be developed. Numerous studies were carried out in the past to identify the effect of various materials and loading conditions for fatigue life of wind turbine blades. However, these models do not consider the effect of manufacturing defects and in-service damages for fatigue life of wind turbine blades. This paper discusses the available fatigue life estimation models for wind turbine blades and their limitations. The paper, propose a framework for developing fatigue life estimation technique for wind turbine blades based on finite element analysis (FEM) stress and strain data.