Modal analysis taking too much time

[loubna.lahnin]

Hello, the modal analyis took over 3 hours and it still running, is it normal ?. i have only 39707 nodes.Thanks for help

[tony.ridley]

did you have instability? mass defined correctly? how many modes are you looking for? too many possibilities without seeing your model

[Rafal.Gaweda]

Hello, the modal analyis took over 3 hours and it still running, is it normal ?. i have only 39707 nodes.Thanks for help

---

File please.

[loubna.lahnin]

I have one instability Rz n node 176 , btw I can't find this node.The file is attached.

I'm looking for 100 modes (modal massse > 90%)

[Rafal.Gaweda]

Lack of file

Try:

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Sending-bigger-files/td-p/3795062

[loubna.lahnin]

I have one instability Rz in node 176 , btw I can't find the node :s. I m searching for 100 modes ( modal mass >90%).

the link:

http://we.tl/VNH5NjoojC

I was trying to apload it from an a hour ago, thank for the trick.

I really apreciate your help

[Rafal.Gaweda]

100 modes - 1740 seconds 

[loubna.lahnin]

Ok so where can I change the solver type? the instability wouldn't be a problem?

[Rafal.Gaweda]

Ok so where can I change the solver type? 

In JOb Preferences \ Structure Analysis.

One remark - you have to perform calculations of 200 modes, maybe more, I do not know yet ,  because there are "cantilever" columns  (56 112 152 153 164 549 551 559 560 563to569 571 753to760 762to769 775 867) generating many local modes without significant mass percentage.

[loubna.lahnin]

I cant get the results now  I have an error message " données incorrectes N°d'erreur 5000"

[loubna.lahnin]

I followed the steps in the link below means that I renamed the file but it doesn't work. I had the same error : incorrect data

 http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=14691229&linkID=12305695

[Rafal.Gaweda]

file with error 5000 please

[loubna.lahnin]

http://we.tl/0gSW34uAM1     regards

[Rafal.Gaweda]

Please update your robot with Service Pack 4 for v.2013 then check.

[loubna.lahnin]

Thansks so much it worked but with a 8 core processor it take a litle bit more than 1h .I have a question : for the modale analysis I should add the masses to the 1-dynamic mass2-global mass or 3-modale case ? Thanks again

print screen is attached

[Rafal.Gaweda]

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Conversion-load-to-mass/m-p/3050232/highligh... - message 3

[tony.ridley]

option 3 only adds the mass to the specific case chosen. the other options add the mass to ALL dynamic cases. Global mass will also add the load to static cases................(as written in the HELP menu 🙂 )