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06:53 Aug-29-2008
Steven
NDTesting of a mechanical connection: Options?

Hi,

I am a mechanical engineer but fairly new to the field of NDT. The problem I am facing is that I need to verify a mechanical connection of one tube press-fitted into another tube.

Currently I am looking at using mechanical vibrations to verify whether they are well connected. When I excite the structure at resonance frequency and measure the respons at a given point, harmonic distortion can give me an idea whether this is well fixed or not. A lot of harmonic distortion means a non-linear contact, hence a bad press-fit. Low harmonic content tells me the system behaves lineary, and thus we can asume good contact and a good press-fit.

This technique can be used I think, but I was wondering whether there are some alternative techniques to solve these kind of problems ?

Thank you,
Steven


 
00:01 Aug-30-2008

Sang Kim

Consultant, NDT Trainer
Guided Wave Analysis LLC,
USA,
Joined Feb 2008
44
Re: NDTesting of a mechanical connection: Options?
Hello Steven,

Yes, you can use long-range guided wave to find the status of connection. Because the MsS guided wave uses from 4 to 250 kHz ultrasonic guided wave, the testing at 3 or 4 frequencies gives you the status of mechanical connection of one tube press-fitted into another tube. If the mechanical connection is strong, the guided wave is reflected at the connection at from low to high frequency. If the mechanical connection is weak, the guided wave at low frequency (less than 100 kHz) generates signal at the connection point, but the guided wave at high frequency (higher than 100 kHz) does not show reflection at the connection point. For detail information please go to this website (http://www.gwanalysis.com/guided-wave-inspection.html) and click on the high frequency application of guided wave (http://www.gwanalysis.com/example-high-frequency-operation.pdf) at the bottom of the page.

Thanks,

Sang

----------- Start Original Message -----------
: Hi,
: I am a mechanical engineer but fairly new to the field of NDT. The problem I am facing is that I need to verify a mechanical connection of one tube press-fitted into another tube.
: Currently I am looking at using mechanical vibrations to verify whether they are well connected. When I excite the structure at resonance frequency and measure the respons at a given point, harmonic distortion can give me an idea whether this is well fixed or not. A lot of harmonic distortion means a non-linear contact, hence a bad press-fit. Low harmonic content tells me the system behaves lineary, and thus we can asume good contact and a good press-fit.
: This technique can be used I think, but I was wondering whether there are some alternative techniques to solve these kind of problems ?
: Thank you,
: Steven
------------ End Original Message ------------




 
06:12 Sep-02-2008

skim

Consultant, NDT Trainer
Guided Wave Analysis LLC,
USA,
Joined Feb 2008
44
Re: NDTesting of a mechanical connection: Options? ----------- Start Original Message -----------
hello
i have practical experienced so when i see practically i can solve this problem


 
01:07 Sep-03-2008
Steven
Re: NDTesting of a mechanical connection: Options? The idea would be to measure the stability of a metal implant in bone. Idealized this would be a tube-in a tube mechanical connection.

Thanks
Steven

----------- Start Original Message -----------
: hello
: i have practical experienced so when i see practically i can solve this problem
------------ End Original Message ------------




 


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