A reflection based lamb wave method for damage detection with signal enhancement using wavelet transforms

The non-destructive testing of components has been a valuable tool for damage detection and health assessment of structures in any field, be it aerospace or railways, civil, etc. There are various conventional methods such as visual inspection, eddy current testing, liquid penetrant test and x-ray shearography. There are also ultrasonic methods such a B and C-scan methods and also lamb wave methods. The major disadvantage of B and C-scan methods is that it is a point-to-point inspection and hence can be very time consuming. This is where lamb wave methods have an advantage in the fact that they can inspect the whole surface of the structure in multiple line scans. --Abstract, page iii