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August 4, 2011, 02:16 |
earthquake spectrum
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#1 |
Member
Hamed
Join Date: Jun 2010
Posts: 43
Rep Power: 15 |
Hi all,
I want to model a tank sloshing with respect to earthquake acceleration. How should I define the earthquake spectrum for ansys cfx? I'm doing mesh motion. Regards; hamed |
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August 4, 2011, 19:40 |
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#2 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143 |
CFX cannot model in the frequency domain like modal analysis in FEA. You are going to have to convert it into a displacement versus time and impose that as a mesh motion.
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August 6, 2011, 10:32 |
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#3 |
Member
Hamed
Join Date: Jun 2010
Posts: 43
Rep Power: 15 |
Thanks for the reply.
If I have a graph of displacment vs time, how should input that to cfx as the mesh displacement? best regards; |
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August 7, 2011, 09:37 |
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#4 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143 |
Have a look at the tutorial examples for how to implement moving mesh.
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August 7, 2011, 10:48 |
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#5 |
Member
Hamed
Join Date: Jun 2010
Posts: 43
Rep Power: 15 |
Thanks. I know how to do mesh motion with a known equation. But know I have the graph of acceleration vs time. If I manage to integrate it and get the plot of displacement vs time, how can I give this as mesh motion. It is not an equation which I could simply enter for mesh motion displacement.
Regards; |
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August 7, 2011, 19:53 |
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#6 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143 |
If you have the equation of motion then why can't you use it?
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August 7, 2011, 21:11 |
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#7 |
Member
Hamed
Join Date: Jun 2010
Posts: 43
Rep Power: 15 |
No I don't have the equation. As I said I just have a graph of displacment vs time. I don't know how to implement this graph to mesh motion.
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August 8, 2011, 05:24 |
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#8 |
Member
Ali Torbaty
Join Date: Jul 2009
Location: Sydney, Australia
Posts: 72
Rep Power: 16 |
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August 8, 2011, 09:08 |
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#9 |
Member
Hamed
Join Date: Jun 2010
Posts: 43
Rep Power: 15 |
Dear Ali,
Can you please be more specific and guide me on this. How should I make the text file and then how can I input it in cfx? Thank you very much. |
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August 8, 2011, 19:26 |
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#10 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143 |
Use a 1D interpolation function. I set these up by generating the function with some dummy data then editting it in the command editor to include your data points.
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