Ultrasonic nondestructive evaluation method for sub-wavelength coatings using matched field processing.

Ultrasonic Signal Processing Platform for Nondestructive Evaluation

Nondestructive Evaluation of Coatings

Bulk and Rayleigh (or surface wave) velocities of ultrasonic waves in chromium coatings on steel were measured and an experimental correlation was found between the surface velocity and the hardness. Since qualitative coating evaluation is commonly made using hardnesses as a guideline, the possibility is herewith presented of using the so und velocities of surface ultrasonic waves for this purp...

Ultrasonic Nondestructive Testing Method for Evaluation of Annular Seals

Drilling boreholes is common practice in geotechnical and geoenvironmental investigations and in various other ex­ ploration, testing, and monitoring appli­ cations. When a casing is placed in a borehole an annular space is created be­ tween the casing and the surrounding soil. If not properly sealed, this annular space can be a potential path for trans­ port of contaminants in the subsurface e...

Image Processing for Nondestructive Evaluation

Digital image processing techniques can improve the interpretation and evaluation of radiographic and acoustic image data as well as the time domain waveforms produced by ultrasonic, eddy current, and acoustic emission in two important ways. First, the image or waveform being evaluated can be enhanced to bring out detail not readily apparent to the observer. Second, the properly enhanced image ...

Deconvolution of ultrasonic nondestructive evaluation signals using higher-order statistics

In ultrasonic nondestructive evaluation (NDE) of materials, pulse echo measurements are masked by the characteristics of the measuring instruments, the propagation paths taken by the ultrasonic pulses, and are corrupted by additive noise. Deconvolution operation seeks to undo these masking effects and extract the defect impulse response which is essential for identification. In this contributio...