Mechanisms of Solid Particle Erosion Damage to Wind Turbine Blades (GFRP) Irradiated by Ultraviolet Rays

Abstract

The current focus on renewable energy is driving installation of a growing number of wind turbines. In recent years, efforts to improve power generation efficiency by using larger turbine blades have resulted in higher blade tip speeds. The glass fiber reinforced plastic (GFRP) used for blade surfaces is subject to wear due to particle impingement from wind, rain, and dust during long-term operation. As the mechanical effect of such particle impacts, erosion is a factor in blade failure. In addition, long-term exposure of operating turbines to sunlight leads to ultraviolet (UV) degradation, which makes blade failure more likely by accelerating erosion. Addressing this issue requires erosion-resistance measures that take into account the effects of UV light, but the precise nature of the relationship between UV degradation and erosion mechanisms remains unclear. In this study, we investigate those mechanisms by reproducing particle impingement on GFRP exposed to UV light in an effort to lay the foundation for more effective erosion-resistance measures. As a result, we clarify that a decrease in the interfacial strength between the fiber and resin is the dominant factor in the process by which UV degradation accelerates erosion in wind turbine blades.