Nonlinear dynamic analysis of tall buildings considering nondeterministic wind loads

Resumo

In recent years, the technological advances of the civil construction associated to a favourable economic
scenario have promoted the project and construction of tall buildings in several countries, such as the United States,
and more recently, some of the Asian countries, like China, Malaysia and the United Arab Emirates. However, the
architectural dareness and also the increasing in the structural project’s slenderness have been crucial to reducing
the natural frequencies values of these buildings, and in some situations, these facts could induce excessive
vibration problems and human discomfort. On the other hand, other aspect generally disregarded in the current
design practice is related to influence of the effect of geometric nonlinearity on the building’s structural response.
This way, this research work aims to develop an analysis methodology to evaluate the dynamic structural behaviour
and assess the human comfort of tall buildings, when subjected to the wind nondeterministic actions, including in
the analysis the effect of geometric nonlinearity. This way, the dynamic structural behaviour of a 40-storey
reinforced concrete building, 140 m high and dimensions of 29.05 m by 9.00 m was investigated. Several numerical
models were developed to obtain a more realistic representation of the structural system, based on the Finite
Element Method (FEM), using the ANSYS program. The results obtained throughout this investigation have
indicated important quantitative differences when the dynamic structural response of the studied building was
analysed, having in mind the effect of geometric nonlinearity.