Wavelet Energy Method Application In Damage Identification

With the economy development and scientific progress, people’s safety requirement is advancing, structural damage identification has become a new research focus in the field of civil engineering.Civil engineering structural damage identification will play an important role in the protecting of people’s life and property. Therefore, it is of important significant and necessity to study on this subject.The main contents in this paper are as follows.1)The background and meanings of slected topic, the existing status of wavelet method using in structural damage detection are introduced. Then the main content,the research idea and goal of this paper are proposed.2)The basic theories and development of wavelet are introduced.As an excellent time-frequency analysis tool,wavelet analysis has adjusted resolution both in time and frequency domain,it is suitable for analysising and processing signals and has great potential in damage detection.At the same time,the ideas and compulation of multi-resolution anlysis and wavelet packet analysis are presented.3) The state and observed equation in each scale in structural dynamics system based on wavelet transform are deduced,the multi-scale analysis characteristics on structural dynamics system is analyzed,and multi-scale analysis principle based on wavelet packet energy spectrum is presented. The damage identification method and process by wavelet packet spectrum are introduced at length through a compulation example.4)The damage identification method and process through wavelet packet enery are introduced, then an new damage index-energy variation index is presented. Then through compulation example, it can be verified that the new index is mor sensitive than the existing one. In this foundation, a damage degree judgement method on single damage location structure is presented, it also be verified by compulation example. Finally, the main research work of this paper are summarized, the existing problems and direction of further research needed are discussed.