Non-Destructive Damage Evaluation Based on Power Method with Time Collocation

Abstract

The objective of this dissertation is to develop a nondestructive evaluation (NDE) method that could accurately locate and evaluate damage in mass, stiffness and damping properties of structural members. The method is based on the power (Refer to the definition in Section 2.2) equilibrium between the undamaged and damaged structural systems. The method is applicable to a variety of structures and has high tolerance capacity to noise. To demonstrate the above characteristics of the proposed method, the following several tasks will be addressed: (1) the application of the proposed method to different discrete systems with exact deformation data; (2) the application of the proposed method to different continuous systems with exact deformation data; (3) the application of the proposed method to discrete and continuous systems with noise-polluted inputs; (4) the validation of the proposed method using field data. The damage detection results from Task #1 and Task #2 indicated that the proposed method can accurately locate and evaluate damage in mass, stiffness and damping of the structure if exact deformation data were given. The results from Task #3 indicated that the proposed method is proved to be effective in locating and evaluating damage at least fewer than 5% white noise. The damage evaluation results from the field experiment showed that the proposed method is applicable to real-world damage detection by providing damage locations and estimations of damage severities.