Investigating Coefficient of Steel Frame Behavior Under the Influence of Structural Geometry

The analysis and design of structures based solely on the elastic behavior of the members and the lack of attention to the plastic behavior in tolerating of the lateral forces leads to noneconomic design. All the regulations in the world, a special coefficient, called the building's coefficient of behavior, which is calculated to reduce the earthquake forces is considered and allows the designer to analyze the elastic structure under reduced forces and design based on its results. The magnitude of this coefficient in the earthquake regulations is based primarily on the observations of the performance of various building systems in past strong earthquakes and based on engineering judgments. Accordingly, many researchers have expressed concern about the lack of reasonable coefficient of behavior, based on research studies and computational backing in earthquake regulations, and emphasized on the correction of these coefficients based on scientific studies. By studying the results of dynamic analysis on the studied structures in two types with behavior factor 6 and behavior 7, it was shown that increasing the coefficient of behavior can play a very important role in the Seismic response. The coefficient of behavior in the building does not have a significant effect on the horizontal displacement of the structure. Because in the buildings of one and four story, according to the 2800, the effect of twisting is not considered, and because of this, the coefficient of behavior in the buildings of one and four floors does not have much effect on the earthquake force.