Investigation of the changes of dynamic caractiristics of the structures under amplitude of vibration

Three models ( the spatial model ,the modal model and the response model) which are used in analysis of the dynamic system are investigated in this thesis . In the following, the random vibration theory is argued considering that the earthquake is of random characteristic. With mentioning the vertical-load carrying systems in buildings, the behavior of the structural system has been studied considering position of center of rigidity and center of mass. The results of the ambient vibration test and the records of earthquake which are applied on various buildings are compared by emphasizing the changing of the dynamic properties in low and high-amplitude vibrations due to some reasons. Considering these explanations because of building?s dynamic properties depend to spectrum based on earthquake ground motion, It is elucidated the changing of building?s dynamics properties by dealing with the response spectrum which known on important method to use the analyses of earthquake. Various example problems (power spectral density analyse, interaction of shear walls with the frame steel, response spectrum analysis, nonlinear time-history analysis, periodic loading ) are solved with SAP 2000 program.