A Global Method for Structural Damage Detection Part I- Theory and Computational Aspects

Using the concept of strain energy change, due to damage at the element level, a new structural damage detection method is developed. The proposed method employs either static or dynamic response of a structure and simultaneously localizes and quantifies multiple damages. It requires only the stiffness and mass matrices of the baseline structure and a few measured responses of the current structure to find the exact location and severity of damage. A numerical example was used to investigate the behavior of the algorithm. It is shown that those mode shapes and static loadings which yield a uniform distribution of strain energy in elements predict the location and magnitude of damage with more accuracy. Some higher mode shapes which might induce significant levels of strain energy in some elements are not always reliable. Finally, it is shown that in order to obtain reliable results, the number of equations (mode shapes or static loadings) must be greater than the number of predicted damaged elements.