Structural Damage Detection Using Time-Frequency Analysis

Frequent occurrences of natural corrosion and other lots of complicated functions cause damage in structures inevitably under an explicated operated environment. The correct evaluation, detection and repair of structural damage play an important role in greatly reducing the loss of lives and properties. Time-Frequency analysis is recently getting utilized in many fields due to its ability to deal with the signal both in time and frequency domains, especially for the merit that it can deal with the non-stationary signals perfectly. Structural damage detection using Time-Frequency analysis is an active research domain in current structure engineering and has strong engineering background. The correlative theory and technology are developing continuously.In this thesis, the theory and its application for structural damage detection based on Time-Frequency analysis are studied carefully. The main efforts are devoted to the following aspects:1.The definition of structural damage and the classification system for damage identification method are given in the thesis. The structural damage is defined as the changes of structural performance, intentional or unintentional , which affects the current or future performance of the system. The damage detection are divided into four levels from simplicity to complexity, currently the study of structural damage detection mostly focus on the level of damage identification.2.We first study the basic theory of Time-Frequency Analysis , then apply Wavelet Transform and Hilbert-Huang Transform to non-stationary signal analysis. Finally , we make a comparison study of these two Time-Frequency Analysis and draw some conclusions.3.The application techniques of Wavelet Transform and Hilbert-Huang Transform for the detection of structural damage are studied in this thesis. And according to the principle of structural dynamic, the structural analysis program is...