In this study, the elasticity modulus for the steel material is identified by the model calibration method using the dynamic characteristics obtained from the environmental vibration data. For this aim, the natural frequencies of the steel bar have been identified by carrying out the vibration test. The same bar has been modelled by SAP2000 finite element program. The experimental frequencies are compared with the results attained from finite element modal analysis. It has been attempted to determine the real value of the elasticity modulus by using the model calibration method. For this purpose, the elasticity modulus is selected as the change parameter and the difference between the experimental and analytical frequencies are minimized. For vibration test, a measurement system consisting of accelerometer and an electronic circuit used as data acquisition unit was designed and the signals were transferred into a computer. These data were analyzed in Matlab program and the experimental frequencies were extracted from these data. The model calibration process was carried out by using the API feature of SAP2000 program with iteration through software generated in Matlab program. In this view, the elasticity modulus which gives the closest result to the experimental measurement results is determined.
Keywords: Natural Frequencies, Material Property, Modal Analysis, Model Calibration, Vibration Test.