where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -

740 views
Technical Discussions
Rolf Diederichs
Director,
NDT.net, Germany, Joined Nov 1998, 617

Rolf Diederichs

Director,
NDT.net,
Germany,
Joined Nov 1998
617
00:44 May-12-1997
Model generated by an inverse Fast Fourier Transformation

Concerning the article "Approximative Modeling for the Practical Ultrasonic Inspections" by H.Wüstenberg, A.Erhard.
The A-Scans are in the model generated by an inverse Fast Fourier Transformation.
What are the advantages and drawbacks of this approach?

Rolf Diederichs



 
 Reply 
 
Hermann Wuestenberg
R & D
BAM Berlin, Germany, Joined Nov 1998, 26

Hermann Wuestenberg

R & D
BAM Berlin,
Germany,
Joined Nov 1998
26
06:37 May-16-1997
Re: Model generated by an inverse Fast Fourier Transformation
: Concerning the article "Approximative Modeling for the Practical Ultrasonic Inspections" by H.Wüstenberg, A.Erhard.
: The A-Scans are in the model generated by an inverse Fast Fourier Transformation.
: What are the advantages and drawbacks of this approach?

: Rolf Diederichs


Pleas find here an first attempt of answering the following question:

1. The model can be linked to well known pulse spectra of UT-probes,
which commonly are available as data measured and also - depending
from the manufacturer - calculated by a KLM-quadrupol model or
similar equivalent circuits for the probe. The influence of the
bandpass filter characteristic of the receiving amplifier within the
UT-equipment can easely be studied.

2. The phase behaviour of reflection or mode conversion factors and of
the point source directivities for the different wave modes and its
influence can be considered without any difficulty

3. This enables us to cut the totality of the process into different
parts and to multiply or add them in order to get the transfer
function of the whole system.

4. The necessary number of frequency samples to be calculated can be
adapted to the extension of the time domain to be considered for the
A-Scan. E.g. many of the examples in the above mentioned contribution
are using 64 samples in the frequeny domain and 128 in the time
domain, which corresponds e.g. to 16 mm sound path length. That means
that the use of the inverse FFT enables us to reach very short
computational times.


The drawbacks have to listed by someone else favorising a time domain
approach.

greetings

and Frohe Pfingsten

Hermann Wuestenberg



 
 Reply 
 

Product Spotlight

Research and Application Development For NDT

Acuren’s Research and Application Development specializes in the development of advanced ultraso
...
nic inspection techniques and systems for challenging inspection applications, with an emphasis on practical solutions which are field deployable. Services include manual and automated ultrasonic inspection system development, inspection technique optimization using laboratory scale studies and ultrasonic modeling (CIVA, BeamTool), preparing technical justification for technique evaluation and qualification (Probability of Detection and sizing accuracy studies), inspection/calibration/analysis procedure preparation to support field deployment of custom techniques, and development of custom imaging algorithms to support challenging inspection applications.
>

Conformable wedge transducer

The conformability is obtained with a flexible membrane filled with water between the transducer and
...
the inspected component. The coupling between the membrane and the component requires a small quantity of water or couplant. The conformable wedge combines the acoustic performance of immersion technique with good coupling and low attenuation.
>

SITEX CPSERIES

Teledyne ICM’s CPSERIES has been designed with a view to revolutionizing the handling and perfor
...
mances of portable X-Ray sets. Despite having managed to halve the weight of similar portable X-Ray generators available on the market (while continuing to provide the same power output), the SITEX CPSERIES generators feature a shutter, a laser pointer, a beryllium window, an aluminum filter and two integrated diaphragms (customized sizes are available upon request). Without compromising the robustness and reliability for which ICM products are renowned, the small size and light weight of the SITEX CPSERIES will radically change the way that you perform your RT inspections. And you will see a positive impact in terms of both quality and return on investment (ROI).
>

CIVA 2020 UT Module

CIVA NDE Simulation Software is the world leader of NDT Simulation. The UT simulation Module incl
...
udes: - "Beam computation": Beam propagation simulation - "Inspection Simulation": Beam interaction with flaws or specimens The user can simulate a whole inspection process (pulse echo, tandem or TOFD) with a wide range of probes (conventional, Phased- arrays or EMAT), components, and flaws.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window