Abstract

The sheds, usually in metal structure, are commonly used for commercial or industrial establishments. Such structures can be designed under the laws established by the Ultimate Limit State (ULS) parameters, Service Limit Status (SLS) or Usage (SLU), even though many of them may be subject to large displacements caused by vibrations, static loads or, even the combination between both. The own weight's structure and the wind dynamic load combined is a perfect example how these structures are subjected to combined forces. Thus, alternatives to control or minimize the excessive displacement are needed. There are several methods of controlling vibration, and this paper presents the bracing system. Shed and 3 different bracing systems were designed, single diagonal, double diagonal and inverted V. These systems are designed to resist vertical and horizontal actions, and its main function is to provide stability to structures when they suffer from wind load action. In this paper NBR 6123/1988 was used to compute wind load. Numerical calculations were carried out in SAP2000 and Visual Ventos, in order to study the dynamic behaviour of the shed submitted to such actions. The analyses were restricted only to displacements in the X and Y directions.
Afterwards, the reinforced structure was compared with that one without bracing. After the computations the minimal X and Y displacement were found for inverted V-shaped bracing system. Furthermore, the reinforce structure also provided great rigidity to the frame and a better distribution of the efforts in the structure nodes.

Abstract

In recent years, the analysis and design of blast resistance structures has been considered due to the increase in terrorist attacks and multiple explosions in various places. Extensive studies of buildings and their response to explosives have been conducted in various countries today. Extensive research is needed to find ways to prevent the demolition of buildings in the face of such events. The predominant type and characteristic of these explosions, which are generally surface explosions, is the use of bulk and concentrated explosives (TNT). In this research, numerical studies have been performed on three-dimensional structural models with 5 and 10 floors with concentrically braced frames (CBF) and eccentrically braced frames (EBF). The nonlinear dynamic method is applied for analyzing the models under the level of blast loadings. The plastic hinge rotation, ductility ratio, performance levels, brace axial forces, shear forces and flexural moments in all models are obtained from the analysis and compared with each other. In according to the results, the EBF systems generally show the better performances than CBF systems under blast loadings.

Abstract

In recent years, the analysis and design of blast resistance structures has been considered due to the increase in terrorist attacks and multiple explosions in various places. Extensive studies of buildings and their response to explosives have been conducted in various countries today. Extensive research is needed to find ways to prevent the demolition of buildings in the face of such events. The predominant type and characteristic of these explosions, which are generally surface explosions, is the use of bulk and concentrated explosives (TNT). In this research, numerical studies have been performed on three-dimensional structural models with 5 and 10 floors with concentrically braced frames (CBF) and eccentrically braced frames (EBF). The nonlinear dynamic method is applied for analyzing the models under the level of blast loadings. The plastic hinge rotation, ductility ratio, performance levels, brace axial forces, shear forces and flexural moments in all models are obtained from the analysis and compared with each other. In according to the results, the EBF systems generally show the better performances than CBF systems under blast loadings.