Fatigue Analysis of a Point Absorber WEC subjected to Passive and Reactive Control

• Published in: Journal of Offshore Mechanics and Arctic Engineering
• Main Authors: Zurkinden, Andrew Stephen, Lambertsen, Søren Heide, Damkilde, Lars, Gao, Zhen, Moan, Torgeir
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: Wave energy converter; Point absorber; Fatigue analysis; Arctic
• Online Access: https://vbn.aau.dk/da/publications/2f91d6b3-5b3d-45a8-8585-91e32f73feb4; https://doi.org/10.1115/1.4030646

This paper investigates the effect of a passive and reactive control mechanism on the accumulated fatigue damage of a wave energy converter (WEC). Interest is focused on four structural details of the Wavestar arm which is used as a case study here. The fatigue model is set up as an independent and generic toolbox which can be applied to any other global response model of a WEC device combined with a control system. The stress responses due to the stochastic wave loads are computed by a FEM model using the frequency-domain approach. The fatigue damage is calculated based on the spectral-based fatigue analysis in which the fatigue is described by the given spectral moments of the stress response. The question will be discussed, which control case is more favorable regarding the trade off between fatigue damage reduction and increased power production.