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03:04 Jan-24-2003
kavita
some questions regarding impact echo

I have some questions regarding NDE and impact echo in particular, for concrete pipes.
1)Has ever been SASW (spectral analysis of surface waves) been used for evaluating the integrity of concrete pipe. Can anybody give me a case study?
2)I've read some where that SASW and impact echo are similar to some extent. to what extent are they similar and hpw are they different.
3)why are S-waves ignored in impact echo testing?

Thanx advance for your answers




 
00:01 Jan-25-2003
kavita
one more question : I have some questions regarding NDE and impact echo in particular, for concrete pipes.
: 1)Has ever been SASW (spectral analysis of surface waves) been used for evaluating the integrity of concrete pipe. Can anybody give me a case study?
: 2)I've read some where that SASW and impact echo are similar to some extent. to what extent are they similar and hpw are they different.
: 3)why are S-waves ignored in impact echo testing?
. 4)what is the difference between impact-echo and impulse response. is it that in impulse response the stress wave is generated by a transmitter and in impact-echo that is done by mechanical impact.
: Thanx advance for your answers
.



 
03:09 Jan-25-2003
Franc Buijsen
Re: some questions regarding impact echo I advise you to contact a company called Andec in Toronto Canada, andec@andec.on.ca. They are very familiar with concrete testing using impact echo.

regards

Franc

: I have some questions regarding NDE and impact echo in particular, for concrete pipes.
: 1)Has ever been SASW (spectral analysis of surface waves) been used for evaluating the integrity of concrete pipe. Can anybody give me a case study?
: 2)I've read some where that SASW and impact echo are similar to some extent. to what extent are they similar and hpw are they different.
: 3)why are S-waves ignored in impact echo testing?
.
: Thanx advance for your answers
.



 
02:42 Jan-31-2003

Christian Grosse

Teacher,
Technische Universität München,
Germany,
Joined Nov 2000
11
Re: some questions regarding impact echo These are several interesting questions and a discussion could be
useful. I am not an expert in SASW, but maybe you can point to a proper
source of information.

Regarding question 3 I am not sure if I understand the benefit you
expect to get using S-waves additionally to P-waves. However, since the
impact usually used in impact-echo testing produces mainly compressional
waves, I would not expect S-waves to be very dominant. These problems
are now addressed by a collaborative research project in Germany (see
http://www.for384.uni-stuttgart.de/) using a combination of experiments
and simulations. The answer is: This is ongoing research.

If you understand impulse response as a technique generating stress
waves by ultrasound emitters, this could be a difference to impact-echo.
To generate high amplitude pulses usually piezo-electric emitters of the
resonant type are used. The idea of impact-echo is instead to use
broadband pulses (pulses with energy over a broader frequency band) to
detect "reverbations" caused by flaws in different depth. This is
another difference to most ultrasound impulse techniques. The amplitudes
generated by broadband piezo-electric emitters are usually too weak.

Christian Grosse


---------------------------------
: I have some questions regarding NDE and impact echo in particular, for concrete pipes.
: 1)Has ever been SASW (spectral analysis of surface waves) been used for evaluating the integrity of concrete pipe. Can anybody give me a case study?
: 2)I've read some where that SASW and impact echo are similar to some extent. to what extent are they similar and hpw are they different.
: 3)why are S-waves ignored in impact echo testing?
.
: Thanx advance for your answers
.



 
00:33 Feb-05-2003
kavita
Re: some questions regarding impact echo Thank You Mr.Grosse!


 
06:16 Mar-24-2003

WILLIAM A. WEBER

Director
IMPACT-ECHO INSTRUMENTS,LLC,
USA,
Joined Mar 2003
2
Re: some questions regarding impact echo : These are several interesting questions and a discussion could be
: useful. I am not an expert in SASW, but maybe you can point to a proper
: source of information.
.
: Regarding question 3 I am not sure if I understand the benefit you
: expect to get using S-waves additionally to P-waves. However, since the
: impact usually used in impact-echo testing produces mainly compressional
: waves, I would not expect S-waves to be very dominant. These problems
: are now addressed by a collaborative research project in Germany (see
: http://www.for384.uni-stuttgart.de/) using a combination of experiments
: and simulations. The answer is: This is ongoing research.
.
: If you understand impulse response as a technique generating stress
: waves by ultrasound emitters, this could be a difference to impact-echo.
: To generate high amplitude pulses usually piezo-electric emitters of the
: resonant type are used. The idea of impact-echo is instead to use
: broadband pulses (pulses with energy over a broader frequency band) to
: detect "reverbations" caused by flaws in different depth. This is
: another difference to most ultrasound impulse techniques. The amplitudes
: generated by broadband piezo-electric emitters are usually too weak.
.
: Christian Grosse
.
:
: ---------------------------------
: : I have some questions regarding NDE and impact echo in particular, for concrete pipes.
: : 1)Has ever been SASW (spectral analysis of surface waves) been used for evaluating the integrity of concrete pipe. Can anybody give me a case study?
: : 2)I've read some where that SASW and impact echo are similar to some extent. to what extent are they similar and hpw are they different.
: : 3)why are S-waves ignored in impact echo testing?
: .
: : Thanx advance for your answers
: .
.CHRISTIAN,

TAKE A LOOK AT OUR WEBSITE, WWW.IMPACT-ECHO.COM; IT HAS CASE HISTORIES AND LOTS OF INFO. WE ALSO SELL THE BOOK ON THE TOPIC WHICH WILL ANSWER ALL YOUR QUESTIONS. SORRY NOT TO REPLY SOONER, BUT I JUST SAW YOUR QUESTION.

BILL WEBER



 


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