Effects of Localized Manufacturing-Induced Porosity Defects on the Fatigue of Wind Turbine Blades

Researcher: Juan Su

Description: Voids are a common manufacturing-induced in wind turbine blades, and they can comprise the overall structural performance of wind turbine blades. The yellow mark in the picture shows porosity cloud on a spar cap, the primary loading-carrying structure of a wind turbine blade. Due to a lack of understanding of the effects of such defects on the in-service fatigue life of a wind blade, it is challenging to make a well-informed decision on the disposition of blades, such as OK to be put in service as is, rework before putting into service or scrapping the blade. As a result, overly conservative subjective decisions on blade disposition are made on past experience. An empirical model which can quantitatively assess the effects of porosity on fatigue life to support disposition could lead to objective and well-informed decisions on blade disposition. In this research, experimental and modeling methods combined with CT scans to characterize voids and porosity are implemented to build such an empirical model to support optimizing the repair scheme to scale down material waste and avoiding unnecessary repair. Meanwhile, it can be a reference to serve in improving blade design to reduce manufacturing scale-up and save production cost.