Wave-induced overturning moments, moment arms, and associated forces on monopile foundations

Journal article

Accurate prediction of wave-induced overturning moments is important for the safe and economical design of monopile foundations for offshore wind turbines. In this study, harmonic-specific moment arms are derived from depth integrals of the inertia force contribution up to the still-water level, yielding closed-form expressions for the effective moment arm associated with each force harmonic. These expressions are assessed against OpenFOAM simulations in an inertia-dominated regime. The results show that the inertia-based formulation, combined with modest harmonic-dependent corrections, reproduces the total overturning moment with high accuracy. Although the present validation uses simulated force harmonics, the same framework can be combined directly with higher-order Stokes-type force models for engineering applications.

Authors: Hlophe, T; Adcock, TAA; Ding, H; Zang, J; Taylor, PH

• Publication status: Accepted
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Coastal Engineering: An International Journal for Coastal, Harbour and Offshore Engineers
• Acceptance date: 2026-05-12
• EISSN: 1872-7379
• ISSN: 0378-3839
• Language: English
• Keywords: wave-induced moments; monopile foundations; offshore wind; higher-order harmonics; CFD validation