Forum Technical Discussions      Re: NDTesting of a mechanical connection: Options? Posted by: Sang Kim (PID_3469), E-mail: Address, on August 30, 2008 at 00:01 : In Reply to: NDTesting of a mechanical connection: Options? posted by : Steven , E-mail: Address, on August 29, 2008 at 16:53 : 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 ------------ Follow Ups: Re: NDTesting of a mechanical connection: Options? skim 06:12 Sep-02-2008 (1) Re: NDTesting of a mechanical connection: Options? Steven 11:07 Sep-03-2008 (0) Post a Followup: Name: E-Mail: Subject: Comments: ----------- Start Original Message ----------- : : 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 : : 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 ------------ Optional Link URL: Example: "http://www....html". Alternative write "http://www.ndt.net/wshop/attach/filename.htm" if you transfered a filename.htm via FTP Page Title: is important! Optional Image URL: http://www....gif Attention! Please click the button only once. This may take a moment to process Forum Technical Discussions Help