Using Wavelet Analysis In Crack Detection at The Arch Concrete Dam Under Frequency Analysis With FEM

The dam is a part of civil works for the irrigation and flood control purposes. Specially, arch concrete dams have important characteristics because of high safety, economical design, designing complexity and its applications. Most of structure failures take place because of ingredients fracture. This event occurred by cracks witch their development is considered as a serious threat for the behavior of the structure. The exhibition methods of the cracks are classified in groups of structural health monitoring (SHM) methods. The effect of cracks on the behavior of a structure is local stiffness differences that have great effects on the dynamic treatment of the structure. This matter is very significant in the difference between natural frequency and mode shapes, so analysis it will be lead to detect the crack.

The new and useful method that has located in the of signal Analysis discussion has encounter with researches reception that is named as Wavelet Transform (WT). This transform is one of the useful mathematic transform methods witch have a high ability in recognition of inconsistencies by index of Wavelet Transform graph in the shape of one or two close points that have noises in relation which other points. So, in this paper, first the theory of wavelet analysis is presented including continuous and discrete wavelet transform followed by its application to SHM. Then, using frequency analysis response of dam with ABAQUS software, crack detection possibility has been researched in dam structure under Wavelet analyzing in MATLAB software toolbox.