brace deformed shape

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zhangs
Posts: 5
Joined: Mon Aug 08, 2022 2:51 pm

brace deformed shape

Post by zhangs » Mon Aug 08, 2022 3:51 pm

In the STKO post-processing process, the support of the deformation diagram is disconnected. where problem went wrong?
Attachments
brace example.zip
(452.22 KiB) Downloaded 10 times
knee brace.jpg
knee brace.jpg (275.22 KiB) Viewed 375 times
have a pattern

Lucy2012
Posts: 42
Joined: Tue May 11, 2021 4:28 pm

Re: brace deformed shape

Post by Lucy2012 » Wed Aug 10, 2022 6:32 pm

You probably did nor merge the geometry, please check it.

zhangs
Posts: 5
Joined: Mon Aug 08, 2022 2:51 pm

Re: brace deformed shape

Post by zhangs » Mon Aug 15, 2022 1:45 am

I merged geometry from the beginning
Attachments
002.png
002.png (366.39 KiB) Viewed 289 times
have a pattern

STKO Team
Posts: 1341
Joined: Tue Oct 29, 2019 8:45 am

Re: brace deformed shape

Post by STKO Team » Mon Aug 22, 2022 12:53 pm

It's a single Wire, but the edges on top do not pass through the brace-end-node (as you can see here, it is a single edge, not physically intersecting the brace-end-node):
WrongEdge.png
WrongEdge.png (81.25 KiB) Viewed 225 times
What You should do is to delete those edges, draw them again as a 3-point, 2-edge lines passing through the brace end-node, and make the wire again:
NewEdges.png
NewEdges.png (167.49 KiB) Viewed 225 times

Finally, you re-assign material and element properties.
Here is the modified file
0010.zip
(150.16 KiB) Downloaded 5 times

zhangs
Posts: 5
Joined: Mon Aug 08, 2022 2:51 pm

Re: brace deformed shape

Post by zhangs » Tue Aug 23, 2022 1:59 am

Thank you for your detailed explanation. But the deformation pattern is still abnormal.It's not the same as the metamorphosis I had in ETabs.It's been going on for a long time. I can't get the right results.
Attachments
00.png
00.png (27.61 KiB) Viewed 213 times
experience.zip
(17.95 MiB) Downloaded 5 times
000.png
000.png (216.43 KiB) Viewed 222 times
have a pattern

STKO Team
Posts: 1341
Joined: Tue Oct 29, 2019 8:45 am

Re: brace deformed shape

Post by STKO Team » Tue Aug 23, 2022 11:37 am

There were some mistakes in the analysis settings:
  • You put both gravity and lateral loads during the gravity analysis. The pushover load should be added after the gravity!
  • After the gravity you should use -loadConst (too keep the gravity load constant) and reset the pseudoTime to 0! this is very important in disp-control analysis
  • Minor improvement: you are using a single Finite Element per structural member. In this case you need the Force-Based beam element, not the Displacement-Based (which needs a refined mesh)
  • You forgot to put the GJ value to the fiber section (it can be singular in torsion)
I also added a monitor to monitor in real-time the pushover curve
Check this:
0010.zip
(156.68 KiB) Downloaded 6 times

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