Evaluation of structural damage identification methods based on dynamic characteristics

In this thesis, structural damage identification methods based on changes in the dynamic characteristics of the structure are examined and new methodologies are also developed. These are based on the modal curvature matrix, the Frequency Response Function (FRF) curvature and the Discrete Wavelet Transform. Damage indices based on the concept of Receptance-Energy are presented to predict the damage location and to estimate the severity of the damage directly from the measured FRF. The methods are evaluated for several damage scenarios in a simply-supported beam and a plane frame. The damage is simulated by reducing the stiffness of assumed elements and by introducing cracked elements at different locations. The results of the analyses indicate that the proposed method based on the Receptance-Energy performs well in detecting, locating and quantifying damage in single and multiple damage scenarios. The numerical examples show that the Wavelets Transform analysis is capable of detecting the discontinuities in the FRF signal to locate damage.