Structural Health Monitoring of Wind Turbine Blades

Abstract

Wind turbine blades usually achieve a very long operating life of 20–30 years. During their operation, the blades encounter complex loading with a high number of cycles as well as severe weather. All of these factors result in accumulated damage, acceleration of fatigue damage, and even sudden blade failure, which can cause catastrophic damage to the wind turbine. In recent years, many structural health monitoring (SHM) techniques, including global and local methods, have been developed and applied as important and valid tools to detect the damage of wind turbine blades. This chapter provides a comprehensive review and analysis on the state of the art of SHM for blades. Then, the SHM techniques are described in detail. For the global method, this chapter discusses mainly the vibration-based damage detection problem for wind turbine blades given the rotation effects. For the local methods, a fatigue damage detection system used for wind turbine blade is developed using high spatial resolution differential pulse-width pair Brillouin optical time-domain analysis (DPP-BOTDA) sensing system and PZT sensors is introduced to detect the tiny damage under static loading.