Modeling and parameter estimation in flexible riserbend stiffener top connection
Ano de defesa: | 2019 |
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Autor(a) principal: | |
Orientador(a): | |
Banca de defesa: | |
Tipo de documento: | Tese |
Tipo de acesso: | Acesso aberto |
Idioma: | eng |
Instituição de defesa: |
Universidade Federal do Rio de Janeiro
Brasil Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia Programa de Pós-Graduação em Engenharia Oceânica UFRJ |
Programa de Pós-Graduação: |
Não Informado pela instituição
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Departamento: |
Não Informado pela instituição
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País: |
Não Informado pela instituição
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Palavras-chave em Português: | |
Link de acesso: | http://hdl.handle.net/11422/13570 |
Resumo: | The flexible riser top connection is a critical region for fatigue lifetime (re)assessment due to large tension/curvature variation and modeling uncertainties. Both the bend stiffener effect on the curvature distribution and top tension time series could be its inherent uncertainties. In this work, a large deflection beam bending model is developed to represent the flexible riser-bend stiffener top connection with I-tube interface, considering the nonlinear bending behaviors of riser and bend stiffener subjected to a top tension with a rotated angle. The corresponding mathematical formulation with multipoint boundary conditions is numerically solved by an iterative procedure in Mathematica. Large deflection response of the top connection and parametric assessments of I-tube length and sleeve curved radius are analyzed in a case study, including the end-fitting curvature and contact forces of riser with bend stiffener and sleeve. A proposed monitoring approach composed by gyrometers installed along the riser/bend stiffener length combined with the Levenberg-Marquardt (L-M) algorithm, is investigated in riser/bend stiffener system to numerically estimate the unknown top tension and polyurethane elastic response. A preliminary feasibility investigation is implemented in a case study with the gyrometer data numerically generated by Monte Carlo simulations. The sensor number and arrangement, loading conditions and direct top connection model may significantly influence the estimations. Furthermore, a full-scale bendingtension test of riser/bend stiffener with the image-based measurements is presented with unknown material response. |