Random Vibration - Very Long Solution Times
Random Vibration - Very Long Solution Times
(OP)
I've been working on a random vibration model that has the following:
#Nodes = 37K, #Elements = 17K, DOF=158K
It's a model of a power supply and the problem is that the solution takes DAYS to solve. There are 116 resonant frequences. If I just try to solve the random vibration with just using the first 40 resonant frequencies, I can get a solution in about 4 hours. But anything longer the computer (Quad Core, 3 MB RAM) takes very, very long.
Any ideas? Being pointed in the right direction would help. Are there any resources that would help in how to handle large problems like this? (Actually I didn't think it was a large problem considering the stats above).
#Nodes = 37K, #Elements = 17K, DOF=158K
It's a model of a power supply and the problem is that the solution takes DAYS to solve. There are 116 resonant frequences. If I just try to solve the random vibration with just using the first 40 resonant frequencies, I can get a solution in about 4 hours. But anything longer the computer (Quad Core, 3 MB RAM) takes very, very long.
Any ideas? Being pointed in the right direction would help. Are there any resources that would help in how to handle large problems like this? (Actually I didn't think it was a large problem considering the stats above).






RE: Random Vibration - Very Long Solution Times
try solving with 10 20 30 resonances and you've already done 40, to see how long they take.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Random Vibration - Very Long Solution Times
I'm also looking for any resources on running random vibration, more than just the basics like I have with Schroff (good book nonetheless).
RE: Random Vibration - Very Long Solution Times
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Random Vibration - Very Long Solution Times
RE: Random Vibration - Very Long Solution Times
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Random Vibration - Very Long Solution Times
Were you talking about contact analysis above? Thanks for the help.
Dave
RE: Random Vibration - Very Long Solution Times
Sounds like you are doing an out of core solution. Cosmos doesn't always use all the RAM so the fact that you are going out of core so soon doesn't surprise me. Task manager can tell you if this is in fact happening if you turn on the VM, page fault and IO data columns. Cosmos also doesn't use multiple cpu cores.
TOP
CSWP, BSSE
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RE: Random Vibration - Very Long Solution Times
In that case you are on the right track.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.