Conceptual modeling and parametric study of the nonlinear dynamics of the floating wind turbine in the presence of primary and internal resonance

In this paper, a conceptual model is proposed to investigate the nonlinear dynamics of the transverse vibrations of the floating wind turbine. The conceptual models are the best tools to capture the most important phenomena in the dynamic response of the systems. First, the surge dynamics of the TLP platform is modeled as a nonlinear spring. Then the fore-aft motions of the wind turbine is modeled as a spring-mass system. Then simulations are carried out to evaluate the time response of the proposed model. Afterward, the FAST code is utilized to verify the proposed model. The internal resonance and its combinations with the primary resonance are studied by the multiple time scale method. Finally, the frequency response curve is obtained and the effect of the various parameters of the system on the amplitude and the stability of the oscillations are investigated.