Design and nonlinear time history analysis of a building with concrete filled composite columns and steel beams

It is very important for the safety of the structures that the behavior of the structures in the earthquake is examined and understood in a close manner. Therefore, various calculation methods have been developed. Structural earthquake performance analysis, which allows the earthquake behavior to be examined in a near-realistic manner, is frequently used today. In order to evaluate the build by performance analysis, firstly, the analysis is done by linear calculation method and then by non-linear calculation method. Developing technology makes structural analysis easier. Especially structural analysis can be done more accurately and faster with the computer programs developed in the last 30 years. In addition, structural systems have become more accurately modelable through studies on the behavior of structural materials used in buildings. In the scope of the thesis study, the structure that consisting of composite column and steel beam is an example that is not shown in practice. It is aimed to examine and understand the behavior and performance of the earthquake in particular. The structure that linear analysis completed evaluation and design based on performance done. With this approach nonlinear deformations and rotations are calculated. Thus, the building model created with current regulations has been tested by performance analysis. The most important purpose in the design of earthquake resistant buildings is to prevent the buildings from being designed to be demolished in accordance with the targeted performance level. In order for the buildings to be designed for this purpose, regulations are issued by countries to guide civil engineers. The linear analysis of the structure has been made with the regulations published recently in our country such as Principles of Design, Calculation and Construction of Steel Structures Code and Turkey Building Earthquake Regulation 2018. TS 500 regulation were used for material properties and load combinations. TS 498 regulation is used for load values. Etabs program was utilized in the design phase with linear analysis. Column and beam elements used in teh structure are modeled as a frame element. Floor elements are modeled as a shell element. The main beams are connected to composite columns with moment frame design. Secondary beams are connected with hinged joint to the main beams. The structure is designed as a high ductility level system. All of the earthquake loads were transferred with frames. The profiles of the main beams are designated as HEB and the profiles of the secondary beams are IPE. For composite columns, concrete filled pipe section composite element is used. The profiles of the main beams are designated as HEB and the profiles of the secondary beams are IPE. For composite column, concrete filled pipe section composite element is used. The building consists of 7 floors. The first floor has a height of 4 meters and the other floor has a height of 3.5 meters. It has 3 openings as 7.5 meters in X direction. In the Y direction, it has 3 openings in 7 meters. The secondary beams are set to be staggered to avoid excessive vertical loads on the main beams. C35 is used as concrete class in the structure. For structural steel class S275 is used. The ground class of the plot located in Yeşilköy neighborhood of Bakırköy, which is chosen as the place where the building will be constructed, is determined as ZC. Equivalent seismic load method was used for the earthquake analysis in the linear analysis. This is due to the lack of the Etabs program in which the linear analysis is performed. The equivalent seismic load method should be applied in order to apply the stiffness reduction of a composite column structure without affecting the earthquake load on the structure. Therefore, the results obtained by modal analysis are not correct. In order to make a more realistic approach to the structural earthquake behavior, the performance-based evaluation and design of the structure, whose linear analysis was completed, was made. With this approach, nonlinear deformations and rotations of the elements were calculated. Thus, the building model created by the current regulations has been tested with performance analysis. Nonlinear performance analysis was analyzed with two separate programs and the results were analyzed comparatively. The structure was modeled with Etabs and OpenSees programs and results were obtained. In nonlinear analysis models of Etabs and OpenSees programs, secondary beams and floor elements are not modeled. Vertical loads were effected on the main beams. Plastin hinges are used in beams. In the columns, fiber element theorem is used. Thus, the damage to the elements is examined and compared. The damage was compared with the damage limits in the Turkey Building Earthquake Regulation 2018. Then the damage of the elements and the building were determined. In the nonlinear analysis, 11 earthquake records were used. Analyzes made with these records in X and Y directions were repeated by rotating the records 90 degrees. Therefore, a total of 22 analyzes were performed. These analyzes were performed in both programs and the results were obtained. Firstly, the periods were evaluated in comparison of the results. Thus, the consistency of the analyzes as the first step was examined. Then the displacement results of the structures were taken and the relative displacements were calculated. The beam rotations were also taken one by one for each record and analysis. When the results were examined, high beam rotation values were observed in the places with high relative displacements. When looking at the damage in the columns, plastic behaviour were not seen as desired. This master's thesis consists of three main parts. In the first chapter, the structural features of the typical building to be designed and linear calculations according to current regulations are mentioned. In order to form the basis for nonlinear analysis, dimensioning operations are done in this section. Assessments were made according to the regulation limit values. In the second part of the thesis, he nonlinear analysis of the structure determined as a result of the linear analysis with time history analysis. The behavior of the structure was understood with the results obtained in this section. In addition, the behavioral differences of the structure defined in the Etabs and OpenSees programs used in the calculations were examined. The approach differences between the two programs were evaluated. In the third chapter, the design results are examined and evaluated with the help of the values obtained as a result of the calculations made in the first two sections. In addition, some suggestions have been made with the experiences obtained at these stages.