Welded constructions play a vital role in power plant components. Power industry utilization of radiography for integrity of welds is a common practice in the vessel manufacturing industry. Recent developments in the field of ultrasonic utilize Time of Flight Diffraction Technique (ToFD) for evaluation of welds with respect to Engineering Critical Assessment approach for evaluation of welds. Re...

The present work evaluates the application of artificial neural networks for pattern recognition of ultrasonic signals using pulse-echo and TOFD (Time of Flight Diffraction) techniques in weld beads. In this study pattern classifiers are implemented by artificial neural network of backpropagation type using MATLAB. The ultrasonic signals acquired from pulse-echo and TOFD were introduced, separ...

Ultrasonic Time-Of-Flight Diffraction (TOFD) is a recent innovation that has proved highly effective for the inspection of steel plates and tubular pipelines and has started to take its way to replace the other ultrasonic testing techniques. TOFD technique has a lot of advantages which make it the preferable technique in material testing. This technique gives accurate sizing, positioning and ch...

Time-of-flight diffraction method (ToFD) is an amplitude-independent sizing method which is based on the measurement of time-of-flight of defect tip diffracted waves. Although ToFD can measure through-wall length of defect accurately, this method is not capable of measuring horizontal defect size. In this paper, a new ToFD method for evaluating horizontal planar defects is presented. The finite...

Ultrasonic TOFD is good at detecting most internal defects, results are available immediately, testing can be performed ‘on site’ – equipment is fully portable, running costs and safety hazards are low. However, TOFD requires experienced operator skills for the interpretation and detection of defects. These days, with advanced technology, ultrasonic testing can be made more accurate, reliable a...

Non Destructive testing of structural materials is an important activity in many industries. Ultrasonic NDT is one such method widely used in this field. Pulse Echo and Through Transmission are conventional testing techniques which use reflected and transmitted sound energy respectively. But these techniques are highly dependent on defect orientation. Time of Flight Diffraction (TOFD) is a rece...

time-of-flight diffraction method (tofd) is an amplitude-independent sizing method which is based on the measurement of time-of-flight of defect tip diffracted waves. although tofd can measure through-wall length of defect accurately, this method is not capable of measuring horizontal defect size. in this paper, a new tofd method for evaluating horizontal planar defects is presented. the finite...

In non destructive testing of materials, the ultrasonic imagery is a field in full rise. Indeed , more than one convivial representation of the results , the operations of detection , localization and sizing of the defects can be carried out automatically by the analysis of synthesized images. The problem breaks up in general into a phase of preprocessing to only limit the quantity of informati...

A recent intercomparison exercise proposed by the Working Group for Numerical Experimentation (WGNE) revealed that the parameterized, or unresolved, surface stress in weather forecast models is highly model-dependent, especially over orography. Models of comparable resolution differ over land by as much as 20% in zonal mean total subgrid surface stress (τtot ). The way τtot is partitioned betwe...