In this thesis, an approach that enables to detect and evaluate the damage situation of structures by taking into account experimentally measured dynamic characteristics of structures under ambient vibrations is introduced. The applicability of the proposed approach is indicated by performing investigations on structural laboratory models. The presented thesis consists of mainly four chapters. In the first chapter, the studies performed on damage assessment and the formulations of the used analytical and experimental methods are given. In the second chapter, the approach proposed for the assessments of damage state of structures and the applications carried out for different damage cases on the steel cantilever beam, two dimensional frame models, one-storey reinforced concrete building, three-storey reinforced concrete building, bridge and dam models are presented. In the third chapter, the presence, location and effect on the structural behavior of damages are introduced for each model by using the data from measurements of the damage case with the proposed approach. In the fourth chapter, the results obtained from the performed studies and recommendations shed lights on the future studies are presented. At the end of this study, it is observed from the investigations on the laboratory models of fundamental engineering structures that the used approach is very powerful on the damage detection and assessment of structures.
Key Words: Analytical Model Calibration, Ambient Vibration Test, Dynamic Characteristics, Damage Assessment, Operational Modal Analysis, Finite Element Method