Search found 41 matches
- Fri Nov 30, 2018 2:20 pm
- Forum: OpenSees.exe Users
- Topic: MASS/Stiffness Matrix Interpretation
- Replies: 2
- Views: 2757
Re: MASS/Stiffness Matrix Interpretation
Take a look at your model builder command: http://opensees.berkeley.edu/OpenSees/manuals/usermanual/403.htm Say you have the SDOF below: x---------------o --->F A fixed end support at "x" and element between "x" and "o" with no support at "o" and a force F app...
- Fri Nov 30, 2018 6:29 am
- Forum: OpenSees.exe Users
- Topic: Applying partial fixity support
- Replies: 5
- Views: 5541
Re: Applying partial fixity support
With the script I have posted you are about 90% of the way to solving your problem. You need to modify the script now to add uniformly distributed load instead of the one point load I inserted and play with the stiffness value of the rotational spring until you get the moment resistance you want.
- Thu Nov 29, 2018 6:42 pm
- Forum: OpenSees.exe Users
- Topic: Applying partial fixity support
- Replies: 5
- Views: 5541
Re: Applying partial fixity support
Your question is a little unclear, but if I wanted to have a beam, with rotational springs at it's ends instead of pins, I might do something like this. # Create ModelBuilder (with two-dimensions and 3 DOF/node) model basic -ndm 2 -ndf 3 # Set parameters for overall model geometry set length 360 # C...
- Mon Oct 17, 2016 4:36 pm
- Forum: OpenSees.exe Users
- Topic: Flat slider bearing on a beam: Unwanted vertical displacemen
- Replies: 4
- Views: 4350
Re: Flat slider bearing on a beam: Unwanted vertical displac
Thanks for the answer. Yes. That is what I did. I recorded the nodal displacements and they do not show the odd behavior. Any idea why the localDisplacements given by the bearing element don't match up with the displacements at its iNode and jNode? I accounted for the different orientation of the tw...
- Mon Oct 17, 2016 2:40 pm
- Forum: OpenSees.exe Users
- Topic: Flat slider bearing on a beam: Unwanted vertical displacemen
- Replies: 4
- Views: 4350
Re: Flat slider bearing on a beam: Unwanted vertical displac
Well who knows why the display is so weird, but it seems that when you graph the displacements of the beam node and the slider node the weird displacement shown in the display is not really there. Not sure what to conclude. I will try using it against my data and see if anything reasonable comes out...
- Mon Oct 17, 2016 12:52 pm
- Forum: OpenSees.exe Users
- Topic: Flat slider bearing on a beam: Unwanted vertical displacemen
- Replies: 4
- Views: 4350
Re: Flat slider bearing on a beam: Unwanted vertical displac
Here is a little model to demonstrate what I am talking about. Please download the ground motions used in the flat slider bearing element examples : http://opensees.berkeley.edu/wiki/index.php/Flat_Slider_Bearing_Element model BasicBuilder -ndm 2 -ndf 3 set gravity 9.81; set mass 10.e3; # Nodes node...
- Wed Oct 12, 2016 2:30 pm
- Forum: OpenSees.exe Users
- Topic: Flat slider bearing on a beam: Unwanted vertical displacemen
- Replies: 4
- Views: 4350
Flat slider bearing on a beam: Unwanted vertical displacemen
Hello, I am having a problem with the flat slider bearing element. I am trying to model a mass sliding along the beam of a moment frame: https://photos.google.com/search/_tra_/photo/AF1QipPQCjQLHptRqQ1dPD6KxAPC9dxK7eQA1vmZVE_G I have placed the slider element between the mid-node on the beam and the...
- Thu Jun 02, 2016 8:08 am
- Forum: OpenSees.exe Users
- Topic: zerolength element with uniaxialMaterial ENT
- Replies: 3
- Views: 3424
Re: zerolength element with uniaxialMaterial ENT
That is odd. I get zero axial in tension.
- Tue May 31, 2016 5:22 pm
- Forum: OpenSees.exe Users
- Topic: zerolength element with uniaxialMaterial ENT
- Replies: 3
- Views: 3424
Re: zerolength element with uniaxialMaterial ENT
Hi. I am also using ENT for some uplift modelling, but I am not getting any tension participation from the element. Here is how I define the material: set E 200000; set matCompSupport 1; uniaxialMaterial ENT $matCompSupport $E; element zeroLength 1 1 2 -mat $matCompSupport -dir 1 -orient 0 1 0 -1 0 ...
- Tue May 31, 2016 4:50 pm
- Forum: OpenSees.exe Users
- Topic: Consideration of P-Delta effect in time history analysis
- Replies: 6
- Views: 5911
Re: Consideration of P-Delta effect in time history analysis
That is the right geometric transformation.
How do you apply the "P" load? Are you using the loadConst command after applying the P load?
How do you apply the "P" load? Are you using the loadConst command after applying the P load?
- Tue May 31, 2016 4:44 pm
- Forum: OpenSees.exe Users
- Topic: rigidDiaphragm
- Replies: 3
- Views: 3261
Re: rigidDiaphragm
Have you looked at this example? http://opensees.berkeley.edu/wiki/index ... l_Building
Otherwise, post your script. It is hard to understand what is happening from your description.
Otherwise, post your script. It is hard to understand what is happening from your description.
- Tue May 31, 2016 4:32 pm
- Forum: OpenSees.exe Users
- Topic: lapack solver failed - Modeling a truss problem
- Replies: 3
- Views: 3623
Re: lapack solver failed - Modeling a truss problem
Take a look at your nodes. The node 6 is unnecessary. Comment out this line and the code works fine. Otherwise you need to restrain it.
- Tue May 31, 2016 7:43 am
- Forum: OpenSees.exe Users
- Topic: difference between Basic and Local Coordinate system?
- Replies: 5
- Views: 4598
Re: difference between Basic and Local Coordinate system?
I have not used it myself, but I would interpret it that way ie. the displacement should be relative... but I would test it first!
- Tue May 31, 2016 6:57 am
- Forum: OpenSees.exe Users
- Topic: difference between Basic and Local Coordinate system?
- Replies: 5
- Views: 4598
Re: difference between Basic and Local Coordinate system?
Ah sorry. I read your post quickly. Look here.. she gives a quick description: http://opensees.berkeley.edu/community/ ... rce#p42683
and also here for a longer description : http://opensees.berkeley.edu/wiki/image ... EvsDBE.pdf
and also here for a longer description : http://opensees.berkeley.edu/wiki/image ... EvsDBE.pdf
- Mon May 30, 2016 2:26 pm
- Forum: OpenSees.exe Users
- Topic: difference between Basic and Local Coordinate system?
- Replies: 5
- Views: 4598
Re: difference between Basic and Local Coordinate system?
It is hard to explain this without a schema. Take a look at this: https://goo.gl/photos/NXLwGy7maGVX16Y7A
If your element's x-axis is parallel to the global x-axis then local and global displacements are the same, if not be careful that you know which one you are recording.
If your element's x-axis is parallel to the global x-axis then local and global displacements are the same, if not be careful that you know which one you are recording.