Eng-Tips is the largest engineering community on the Internet
Intelligent Work Forums for Engineering Professionals
-
Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
Frequancy calculation
- Thread starter femboy
- Start date
Well, first of all you can spell frequency correctly. Second, you can word your question in a way that is comprehensible - and with enough detail - to allow people to give you some guidance.
------------
See faq569-1083 for details on how to make best use of Eng-Tips.com
------------
See faq569-1083 for details on how to make best use of Eng-Tips.com
- Thread starter
- #3
Thank you Drej. Frequency. There are 6 motors and their revolution speed is 3000RPM. I want to calculate frequency of the system. OIf there are only one motor, I can calculate of frequency of the system as 50Hz. How can I calculate the frequency produced by 6 motors?
femboy,
Perhaps you could post a picture, or some more information about the geometry that you're analyzing? The number of motors and their operating speed should not matter to your FE modal analysis, other than adding weight (and perhaps stiffness) to your assembly.
You'll want to compare the natural frequencies that you compute to the forcing frequencies that are generated by the motors, and perhaps the 2/rev, 3/rev, 4/rev frequencies (and so on) when post-processing. If you're dealing with a geared drive, pay special attention the number of gear teeth and the rotating speeds of the gears: these are possible sources of vibration forcing.
A good tool for finding potential harmonic problems is a Campbell diagram. If the operating speed of the motors is near a crossing on a Campbell diagram (especially at the lower per-rev lines), you may have harmonic excitation problems.
//signed//
Christopher K. Hubley
Mechanical Engineer
Sunpower Incorporated
Athens, Ohio
--
Perhaps you could post a picture, or some more information about the geometry that you're analyzing? The number of motors and their operating speed should not matter to your FE modal analysis, other than adding weight (and perhaps stiffness) to your assembly.
You'll want to compare the natural frequencies that you compute to the forcing frequencies that are generated by the motors, and perhaps the 2/rev, 3/rev, 4/rev frequencies (and so on) when post-processing. If you're dealing with a geared drive, pay special attention the number of gear teeth and the rotating speeds of the gears: these are possible sources of vibration forcing.
A good tool for finding potential harmonic problems is a Campbell diagram. If the operating speed of the motors is near a crossing on a Campbell diagram (especially at the lower per-rev lines), you may have harmonic excitation problems.
//signed//
Christopher K. Hubley
Mechanical Engineer
Sunpower Incorporated
Athens, Ohio
--
- Status
Similar threads
- Locked
- Question