Title:	Design of an optimal pendulum-tuned mass damper applied to offshore wind turbines
Authors:	Colherinhas, Gino Bertollucci
metadata.dc.contributor.email:	ginobertollucci@hotmail.com
Orientador(es)::	Machado, Marcela Rodrigues
Coorientador(es)::	Morais, Marcus Vinicius Girão de
Assunto::	Offshore wind turbine Pendulum tuned mass damper Genetic algorithm optimization Structural control Power spectral density analysis
Issue Date:	27-May-2021
Data de defesa::	10-Nov-2020
Citation:	COLHERINHAS, Gino Bertollucci. Design of an optimal pendulum-tuned mass damper applied to offshore wind turbines. 2020. xviii, 143 f., il. Tese (Doutorado em Ciências Mecânicas)—Universidade de Brasília, Brasília, 2020.
Abstract:	Offshore Wind Turbines (OWT) may experience excessive vibration levels caused by the actions of wind, waves, rotor torque, and seismic loads. To suppress the vibrations of these primary structures, the Tuned Mass Damper (TMD) is a widely used passive control alternative. Briefly, it is a damper that transfers the kinetic energy from the main structure to a secondary mass usually attached to the hub. These devices need to be finely tuned with a target self-vibration mode of the primary structure to work as dampers, otherwise, they could amplify structural vibrations. This thesis presents optimal parameters of a Pendulum-TMD (PTMD) to mitigates structural vibrations of OWTs levels. The PTMD is examined on a National Renewable Energy Lab (NREL) monopile 5 MW baseline wind turbine model using analytical and numerical procedures, such as a 2-degree-of-freedom (2DOF), spectral elements (SEM), and finite elements (FEM). Following design standards of OWTs structures wind and wave spectra computation, as well as the evaluation of the hydrodynamic and aerodynamic loads by computing the resultant peak displacement response at the OWT hub by a Power Spectral Density (PSD) analysis. In the validation of the OWT models, a result comparison is made with the NREL OpenFAST, finding good matching between the results. An in-house built Genetic Algorithm (GA) toolbox, coded in MATLAB® , is used then to optimally design parameters of a PTMD attached to the OWT. The chosen GA fitness function targets a minimization of the peak responses. The design parameters of the PTMD are the flexural rigidity and damping, the mass ratio, and the pendulum length.
metadata.dc.description.unidade:	Faculdade de Tecnologia (FT) Departamento de Engenharia Mecânica (FT ENM)
Description:	Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2020.
metadata.dc.description.ppg:	Programa de Pós-Graduação em Ciências Mecânicas
Licença::	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.bce.unb.br, www.ibict.br, http://hercules.vtls.com/cgi-bin/ndltd/chameleon?lng=pt&skin=ndltd sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra disponibilizada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
Agência financiadora:	Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
Appears in Collections:	Teses, dissertações e produtos pós-doutorado

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