The Application of Wavelet Transform in Damage Identifications of Pipes

• Main Author: 謝濬鴻
• Other Authors: 洪士林
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/47315573524510135437

碩士 === 國立交通大學 === 土木工程系所 === 94 === This thesis proposes an application of NDT method for damage identification of pipes. A numerical model is employed to process simulate accelerative responses of pipes which are subjected to the stiffness degradation damage in circular.First,a finite-element software is employed to establish the database of identification parameters.The wavelet transform is then adopted to process the signal from impact tests performed in FEM model.Finally, the damage location and the degree of damage is diagnosed by comparing analyzed results with parameters in the database.The accelerative responses are decomposed into several different frequency regions by the multi-resolution technique of wavelet analsys.It uses the energy variation of sub-signals in specific scale to diagnose damage.Testing the identify system by four cases,it reveal that the proposed model has excellent performances in damage identification except that damage is close to two supported ends.