Análise dinâmica de edifício de seção H sob ação do vento

Abstract

The verticalization of large urban centers is an architectural trend and a necessity, given the scarcity of land and its high cost. While low and heavy buildings do not suffer from the dynamic effects of the wind, tall, light and slender buildings face this difficulty. Thus, there is a need to apply more precise methods in determining the load due to the wind and also in the dynamic analysis of the structure. This work analyzes a tall building of H-shape. This type of geometry is used for architectural reasons to meet the criteria of ventilation, lighting and, sometimes, to meet the utilization coefficients and occupancy rate. Normative standards usually adopt regular geometries for determining the wind load, thus arises the need to seek more reliable means, such as the reduced model test in a wind tunnel. In this work, the computational model test was performed using Computational Fluid Dynamics (CFD), validating the results in comparison with data obtained in a wind tunnel. Dynamic wind load is applied by the Synthetic Wind Method. Determining the wind load is only one step in the problem, since it is also necessary to determine the structure’s response by means of a dynamic analysis and understand what effects the simplification of obtaining the load generates on the building. The structure analysis is performed using Finite Elements Method and the Hilber-Hughes-Taylor (HHT) Method lasting 30s. Thus, the objective of this paper is to evaluate the dynamic behavior of the building with type H-shape by the action of the wind. This work presents an important contribution in the field of dynamic analysis, highlighting how displacement amplifications occur and the behavior of the structure response function. For the structural analysis with incidence of wind at 0º there was a reduction in the responses, highlighting the frontal displacements that reduced 32%. At 45º, the displacements at the top had a reduction in the order of 25% in the H-shape. The critical case of the analysis was for incidence at 90°, where the frontal displacements suffered an increase of approximately 15%, which can lead to underdimensioning and consequent to a possible collapse of the structure.