The main purpose of this paper was to study the vertical settlement offshore wind turbine (OWT) monopile support structures, where 5, 10, 15, and 20 MW OWT structures were analyzed under power production, seismic, tropical cyclone loads. Moreover, a t-z spring with shear torsional degrees freedom developed simulate stress along pile soil surface combined effect loads z-direction torsions. This ...

This paper investigates the use of an augmented pendulum absorber for damping tower vibrations in monopile-supported wind turbines. A shunted electromagnetic transducer is proposed to replace classic viscous dashpot absorbers, order improve performance and durability absorber. series RCL (resistive-capacitative-inductive) network designed as supplemental shunt transducer, which together with in...

In this paper, an analytical method for vibrations analysis of offshore wind turbine towers with fixed monopile platform is presented. For this purpose, various and the most general models including CS, DS and AF models are used for modeling of wind turbine foundation and axial force is modeled as a variable force as well. The required equations for determination of wind turbine tower response ...

Approximately 75% of installed offshore wind turbines (OWTs) are supported by monopiles, a foundation whose design is dominated by lateral loading. Monopiles are typically designed using the p-y method which models soil-pile resistance using decoupled, nonlinear elastic Winkler springs. Because cyclic soil behavior is difficult to predict, the cyclic py method accounts for cyclic soil-pile inte...

In this study, a total number of 20 centrifuge tests were carried out to investigate monopile behaviour under lateral cyclic loading. The instrumented model pile simulates an offshore wind turbine foundation with embedment ratio 5 installed in sand layers two relative densities 80% and 50%. influence the directional characteristic amplitude load on was studied. data analysis focused accumulatio...

This paper investigates the influence of scour erosion on mode shapes National Renewable Energy Laboratory (NREL) 5 MW offshore wind turbine (OWT) in varying soil conditions, where modes are derived from and wave-induced accelerations. A numerical model, which considers aerodynamic hydrodynamic loading with soil-structure interaction (SSI) servo-dynamics, is developed. The superstructure modell...