Harmonic Response - Frequency response deformation

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  • Last Post 19 February 2020
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rabaur29 posted this 12 February 2020

After identifying resonance peaks from frequency response, I'm wondering how can I identify in more specific detail in Ansys, where the particular concern of resonance is located and which particular component would require structural modification/bracing etc.? if possible

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peteroznewman posted this 12 February 2020

I can't see the scale of the equipment, but I see that the peak amplitude is 2.7 mm.  Is this large enough to be a concern?  Why is this a concern?

If it is a concern, you can see the two peak frequencies are close to 11 Hz and 28 Hz.  When you select a result case close to 28 Hz, where on the machine is the peak displacement? What direction is the displacement in? You can tell this by playing an animation, or make three plots of Directional Deformation and look at X, Y and Z separately, and determine which one has the largest value.  With this knowledge from the simulation, fasten an accelerometer at that location to measure acceleration in that direction.  In that way, you can validate your model, since you can plot acceleration from your model and make a direct comparison to a measured value on the machine.

Run a Modal analysis and determine which mode is close to 11 Hz and which mode is close to 28 Hz.  Looking at the animation of each of those mode shapes should give you an idea of where to put a brace.  If you want to archive your model, I would be interested to take a look, and some others here might also look.

If you can share your model, right click on Mesh and Clear Generated Data, then save the model and close Mechanical. In Workbench, use File > Archive and save a .wbpz file.  You can attach that file type after you reply.   In your reply, say what version of ANSYS you are using.

rabaur29 posted this 18 February 2020

Hi Peter, thanks for your feedback very helpful, I have managed to archive it and will attach file

peteroznewman posted this 19 February 2020

There is a 120 MB file size limit for using Attach.  If your file is larger than that and you have a Gmail account, you can attach the archive file to a new email. That will upload it to your GoogleDrive storage and put a link to the file in the email.  You can copy and paste that link into your reply.  It works the same with Microsoft and OneDrive.

And say what version of ANSYS you are using.  If you are using an older version and I do some work in a newer version, you will not be able to open the file if I send it back to you.

rabaur29 posted this 19 February 2020

Thank for that yes i noticed it didn't work as the file is approx. 300mb, so been stored in the link below:

https://drive.google.com/open?id=1v--A1IEBeHY0FYg8NmlUhQFVe9RokA8l

I am using Ansys 2019 R3

 

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