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01:38 Dec-13-2002
Stefan Hartmann
Phased Arrays

Could anyone tell me how Phased-Array-Systems work or does anyone know where I can find information on that topic?


 
02:31 Dec-13-2002
M. Anderson
Re: Phased Arrays : Could anyone tell me how Phased-Array-Systems work or does anyone know where I can find information on that topic?
. The basic premise for all PA systems involves an array transducer consisting of a set of small, individual elements that are independently driven. Although these elements may be pulsed individually, or in groups, to simulate conventional transducer excitation, the real strength of this technique lies in the capability of the system to electronically delay these elements during both generation and reception of ultrasonic signals. The wave-fronts produced by subsets of elements interact within the inspected component to produce a resultant, phase-integrated ultrasonic wave. The PA system can therefore steer and focus the integrated ultrasonic beam within the component.



 
06:37 Dec-14-2002
Cliff Rawlinson
Re: Phased Arrays : Could anyone tell me how Phased-Array-Systems work or does anyone know where I can find information on that topic?
.
Please visit our web site www.auto-ut.com

We have the Worlds first and only auto-ut simulator.

Now training can be done on a lap top


 
07:22 Dec-16-2002
Jeff Leak
Re: Phased Arrays
Stefan -

I have been using phased-array UT (PAUT) for about three years now. We use a system built by R/D Tech to inspect a new type of weldment called "Friction Stir Welds" (FSW).

The PAUT has a 'water wedge', similar to immersion, and is very adapt at finding extremely tight lack-of-penetration, where other methods such as RT, PT, and even conventional UT, will have major troubles detecting the flaw.

NASA and Lockheed-Martin are implementing this PAUT inspection on the new FSW on the External Tank. Boeing has been using the PAUT on FSW as well, and recently launched a rocket with FSW inspected by the R/D Tech system.

http://www.rd-tech.com/

Hope this helps.

Jeff





 
09:13 Dec-16-2002

Paul A. Meyer

R & D,
GE Inspection Technologies,
USA,
Joined Nov 1998
47
Re: Phased Arrays :Hi Stefan,
I am sure you understand that a sound field can be focused using a lens or a curved piezoelectric source. These techniques delay the sound from some areas of the aperture relative to other areas.
In a phased-array system, the active transducer area is segmented into smaller areas, each of which can be controlled independently. By delaying certain areas, the resulting sound field can be made to simulate a focused or steered transducer. The advantage is that the steering and focusing are under electronic control and can be changed on a rep-rate basis.

I have some PowerPoint presentations that demonstrate the process. Contact me and I'll send you a copy.

Paul

Could anyone tell me how Phased-Array-Systems work or does anyone know where I can find information on that topic?
.



 
01:41 Dec-18-2002
Joerg Schulze-Clewing
Re: Phased Arrays : Could anyone tell me how Phased-Array-Systems work or does anyone know where I can find information on that topic?
.
Hi Stefan,

A good resource is the "Radar Handbook" by Skolnik,
chapter 7 in the 2nd edition. Radar phased arrays are
similar and I use this resource a lot although my
work is in medical ultrasound.

Good luck, Joerg.



 


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