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mhscott wrote: ↑Tue Nov 29, 2022 4:30 am You don't have to use fiber sections. You can, for example, use a section aggregator inside a force-based element.
https://portwooddigital.com/2021/07/04/ ... ggregated/

Hello,
Thank you for the link.
I just interest in static analysis, so I think i do not need hysteresis as in the link. What i do need right no is taking the interaction of axial load and biaxial bending into account for analysis. the Euler hypothesis about beams which plane sections remain plane. and also uniaxial material.
For example this simple case:


L = 3m and P = 10kN

and this section



with steel and concrete with the uniaxial non-linear material:





So what other element expect fiber element i can use for this purpose?

There is loading, but there is NO unloading, so material stress-strain curve is NOT depended to loading

Thanks in advanced

Hi,
I need to analyze a structure consist of armed concrete beam and columns (say for example single span single level frame at simplest form)
Need static nonlinear (both material and geometrical non-linearity) analysis .
I'm aware of fiber element, which could be used to model material non-linearity. is there any other 1D element which can be used to model material non-linearity of concrete beam or column? note that to reduce computation cost, I rather to reduce DoFs by use of 1d elements (like beam column) instead of 2d (like shell) or 3d (like brick).

Thanks

I've found the problem. I was applying nodal load to a fixed node .
This is correct code and correct output:
https://gist.github.com/epsi1on/388230f ... 83a9bc4be1
https://gist.github.com/epsi1on/2128fd5 ... fbed747425
Thanks anyways...

yekose wrote:
> I am not really sure but try to use the nodes as follows,
>
> Node *node1 = new Node(1, 6, ix, iy, iz);
> Node *node2 = new Node(2, 6, jx, jy, jz);
> Node *node3 = new Node(3, 6, kx, ky, kz);
> Node *node4 = new Node(4, 6, lx, ly, lz);
>
> with 5 parameters not 6.
Hi,
Thanks, i was using this code (one extra 0 after coordinates)

Node *node1 = new Node(1, 6, 0.0, 0.0, 0.0, 0);

I've fixed it and edited code above with changes, but still same result.

Hello,
I'm trying to model a single ShellDKGQ file with c++, here is my code:
https://gist.github.com/epsi1on/9a671b8 ... 86602691b5
My problem is after solve i do get zero displacement on nodes and loads stays unbalanced (output from above code):
https://gist.github.com/epsi1on/b2ff22c ... 4138fc2874
Do you know how i can properly use it?

Thanks

What parameters are allowed to use for this element with element recorder?
Currently i'm using this command on a model with all elements of type ShellDKGQ :

recorder Element -xml "elm.xml" -time -closeOnWrite stresses

to get stress values in Gauss points in all element and write them into xml file.
Problem is that all values are zeros in written file:

<Data>
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
</Data>

Am i missing any parameter in recorder command?

Hi,
I have worked with C#.net briefly in several years and I think having Opensees .NET Framework interface (or CPP/CLI) would be quite useful and popular.

Thanks

i was able to export global stiffness matrix of whole model with printA command (look at http://opensees.berkeley.edu/wiki/index ... tA_Command)

Hi all,
I am trying to analyze a I beam model with ShellDKGQ element, Here is images of my model generated in another software:
- Model overall look: https://ibb.co/kHK7gk
- Model with showing nodes (red) and supports (green) and applied forces (pink): https://ibb.co/edVzSQ

- input file model.tcl: https://pastebin.com/VQ7RXsr6
- output file elements.xml: https://pastebin.com/NfB0f8FD
- output file nodes.xml: https://pastebin.com/kibTVejP

I want to get Nodal Displacements and Elements Internal Stresses at Gaussian point into xml files, so I use these TCL commands:

recorder Node -xml "nodes.xml" -dof 1 2 3 4 5 6 disp
recorder Element -xml "elements.xml" -time -closeOnWrite stresses

When i analyze the file like this in OpenSEES command line:

OpenSees > source model.tcl

The nodal displacements and element forces are written successfully.
The problem is that shell elements internal force are very odd, only 0 and 1 in elements.xml file! (please have a look at above link for elements.xml)
Am i making a mistake in definition or other places or elements have this very odd type of internal force?

Any comment would be appreciated.
Thanks