Banca de DEFESA: Thiarly Feitosa Afonso de Lavôr

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Thiarly Feitosa Afonso de Lavôr
DATE: 28/07/2023
TIME: 14:00
LOCAL: Plataforma Teams
TITLE:

DYNAMIC ANALYSIS OF THE STANDARD TALL BUILDING UNDER WIND ACTION

KEY WORDS:

Interference effects; Wind tunnel; Tall buildings; Static analysis; Dynamic analysis; HFPI; BD3GDL; NBR 6123.

PAGES: 257
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Estruturas
SPECIALTY: Mecânica das Estruturas
SUMMARY:

With the increase of urban occupation, and consequently its economic valuation, combined
with the development of construction techniques and materials, the construction of skyscrapers
is already a Brazilian reality. Such structures are susceptible to the development of severe
aerodynamic phenomena including the so-called interference effects. These effects arise due to
the change in wind load caused by buildings or obstacles present in the surroundings of the
analyzed building, and can be amplified or reduced. Understanding and quantifying the
interference effects is essential to design safe and efficient buildings, however, this is a complex
phenomenon that characterizes it as the greatest challenge of wind engineering and thus limits
improving design guidelines in a normative way. The study proposes the estimation and
analysis of these effects through interference factors, considering the changes in the global
aerodynamic loads on a tall building due to the presence of buildings in the surroundings,
relating them to the situation of the building analyzed in isolation. For this, two experimental
techniques were carried out in the wind tunnel of the Federal University of Rio Grande do Sul:
1) High Frequency Pressure Integration (HFPI) and 2) Aerolastic method with the Dynamic
Balance of Three Degrees of Freedom (BD3GDL). By measuring the wind pressures by the first
technique, the static analysis of the global aerodynamic coefficients and the dynamic analysis
of the global forces in a time history, according to the random vibration theory, were
performed. The static analysis, with an analytical-experimental approach, aims to increase the
database about the wind-induced interference effects on buildings, in addition to contributing
to the basis for updates to the Brazilian standard ABNT NBR 6123, particularly on the subject
discussed in its Annex G. The dynamic analysis was performed to analyze and verify the
presence of amplifications in the building responses caused by resonant phenomena. As the
dynamic analysis by HFPI comes partially from a numerical approach, some limitations are
intrinsically included in the methodology, not considering the effects of fluid-structure 

interaction. These limitations were evaluated based on the results from the second
experimental technique that allows aeroelastic modeling of structures. The results showed
excellent consistency between the experimental techniques up to wind velocities encompassing
the maximum velocities used in major standards worldwide. However, the type of analysis
substantially affects the interference effects, modifying both the magnitude and location of the
most critical interference factors. In general, the results obtained confirmed the complex
nature of the phenomenon. However, the magnitude of these results were consistent with the
values determined by referenced standards and researches. In divergence with the Brazilian
standard only in the coordinates of the critical effects, since this standard clearly lags in this
parameter, requiring revision.

COMMITTEE MEMBERS:
Presidente - ***.843.298-** - JOSE LUIS VITAL DE BRITO - UnB
Interna - 1225412 - GRACIELA NORA DOZ DE CARVALHO
Interno - 404485 - LINEU JOSE PEDROSO
Externo à Instituição - ADRIÁN ROBERTO WITTWER
Externo à Instituição - GREGÓRIO SANDRO VIEIRA - UFU