Investigation of the effect of structural damping on wind turbine wind-induced fatigue loads

This paper presents a quantitative investigation of the effect of structural damping ratios of the tower and blade vibration modes of wind turbines on wind-induced fatigue loads at critical blade and tower sections. Fatigue loads are used as a relative measure of fatigue life in wind turbine design applications. By increasing the structural damping ratio of each one of the critical structural modes which highly contribute to the overall vibration response, short-term and lifetime fatigue loads at critical tower and blade sections are calculated considering parked and operating conditions for different mean wind speeds as well as lifetime operational conditions.