Análise Estática e Dinâmico do Efeito de vento em Edifício de Estrutura Metálica

Análise estática e dinâmico do efeito de vento em edificio de estrutura metálica

With the increase in technology and research on materials, especially steel, the metal profiles that are part of the metal structure are being increasingly requested, in order to reduce the weight of the structure, making them more economical. On the other hand, these structures have become increasingly lighter and more slender, being more susceptible to other efforts and phenomena of dynamics and instability, which derive from this slenderness.

Thus, structural analysis techniques that allow the correct identification of these phenomena are necessary. Slender metal structures are constantly subjected to wind stresses.

The large-scale air movement characterized as wind reaches the highest buildings, the wind action in tall buildings can be characterized as lateral loading, which is in the study area of ​​dynamic loads which are loads whose magnitude, direction and position vary in time. The response of the structure arising from dynamic loads is expressed in vibrations and displacements of the structures, these responses can be intensified in relation to the height of the building.

 These requests can cause the structure to have effects greater than those calculated when a static model is used for analysis. Therefore, dynamic analysis is required in such cases. The realization of this type of analysis allows determining the values ​​of displacements, tensions and accelerations of the structure that reflect the effects caused by dynamic actions and that are not detected in a strictly static analysis.

 The Brazilian Standard NBR 6123 - Forces Due to the Wind in Buildings (ABNT, 1988) limits the dynamic structural analysis, allowing, in some cases, that the dynamic efforts caused by the wind in slender structures are considered as equivalent static efforts. To meet this simplification, one must determine the natural frequency and fundamental period of the structure, which, if it is less than one second, may be dispensed, if this is not the case, this should be done.

In view of what was exposed, the objective of the work is to perform numerical modeling by means of fine element model in the Abaqus of a 25-story structure with a total height of 220 meters and then analyze the static response due to the wind effect and the dynamic response due to the wind (time domain), in order to show the importance of the dynamic analysis and finally compare the results obtained with the required in the Brazilian Standard of Wind on Buildings.

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