Banca de DEFESA: Yago Machado Pereira de Matos

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Yago Machado Pereira de Matos
DATE: 07/06/2024
TIME: 08:30
LOCAL: Sala Teams (On-line)
TITLE:

EXPERIMENTAL AND NUMERICAL EVALUATION OF WIND TURBINE PROTOTYPE FOUNDATIONS MECHANICAL BEHAVIOR IN TROPICAL SOIL

KEY WORDS:

Wind turbine; Soil-structure interaction; Load test; Numerical analysis

PAGES: 203
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Geotécnica
SUMMARY:

Nowadays, despite the implementation of new wind farms in Brazil, it still is difficult to form partnerships with companies in the sector, which significantly contributes to the gap in information provided by national literature and the lack of knowledge about the mechanical behavior of wind turbines subjected to transient wind effects. Therefore, through a Research and Development Project to optimize and improve modeling in wind systems, the Brazilian electric power company Eletrobras Furnas aims to facilitate the construction of smaller wind turbines to supply energy to regions far from the Brazilian coast that do not have high generation potential due to the incidence of low-speed winds. The aim of this study is to evaluate the behavior of EOL-10 and EOL-40 wind turbine prototypes foundations on tropical soil in the Midwest of Brazil using data from the structures' instrumentation, load tests and numerical modeling results using the Finite Element Method (FEM). The load tests carried out on test piles revealed some peculiarities about soil-structure interaction for the study site, such as the variation in cyclic secant stiffness, the shaft friction degradation after cyclic axial compression loads and the permanent accumulation of pile-head displacements after cyclic transverse loads. Simulations of these tests revealed that the combination of concrete damage plasticity model for concrete and Mohr-Coulomb for soil can be useful for investigating the behavior of wind turbine prototypes foundations if it is carried out for a few cycles and at a high load level. Considering the main geotechnical design requirements for wind turbine foundation, numerical analyses of prototype foundations were carried out for (i) extreme loads; (ii) ordinary loads; (iii) cyclic loads; and (iv) resonance. The results suggested foundations guaranteed safe performance for proposed load scenarios. On the other hand, it was observed that both EOL-10 and EOL-40 may experience events of resonance. However, both prototypes have a data acquisition system equipped to carry out their structural monitoring with sensors distributed throughout their towers. The modal analysis also revealed that assuming a completely fixed tower may lead to error in natural frequency prediction and considering soil small-strain stiffness may influence with the displacements of its foundations. Also, the first natural frequency is responsible for the largest displacements in the structure.

COMMITTEE MEMBERS:
Externo à Instituição - ALFRAN SAMPAIO MOURA - UFC
Interno - 2161425 - JUAN FELIX RODRIGUEZ REBOLLEDO
Interno - 1549489 - MANOEL PORFIRIO CORDAO NETO
Externo à Instituição - RENATO MARQUES CABRAL
Presidente - 1122864 - RENATO PINTO DA CUNHA