API for geometry?

[kolozvari]

Thank you. It makes sense. When you get a chance, it would be useful to provide an example on how to define physical and element properties.

Thank you in advance.

Regards

[kolozvari]

Thanks again for your help with this. I have two follow up questions.

1) When I try to load and assign the properties to the entire model, which has ~5200 beam-column elements, STKO crashes. It appears that my RAM memory limit is reaches because when I load 1000 elements at a time, STKO doesnt crash. Is that possible? If so, is there anything I can add to the api code to pause the loop every 1000 elements, which would free the memory, so I dont have to have multiple input files?

2) I am using Custom section and I enter the values of sectional properties manually for all sections. However, it seems that the graphical representation of these sections is totally off and they all appear very large, as shown in the screenshot below. This makes is almost impossible to use the model since I cannot see well beams and columns Is there any way to control the size of the section in the graphical representation when Custom sections are used?

api.JPG (102.98 KiB) Viewed 3076 times

Looking forward to hearing from you.

Thank you,

[STKO Team]

1) When I try to load and assign the properties to the entire model, which has ~5200 beam-column elements, STKO crashes. It appears that my RAM memory limit is reaches because when I load 1000 elements at a time, STKO doesnt crash. Is that possible? If so, is there anything I can add to the api code to pause the loop every 1000 elements, which would free the memory, so I dont have to have multiple input files?

It seems really strange that a RAM limit is reached for this kind of scripts. I think it's realted to the automatic regeneration done by STKO when assigning properties because now STKO runs the regen command on a parallel thread in c++ that probably conflicts with the thread the Python code is run into.
If you can share your script I will try to run it in the new version (4.0.0) that we will release soon, in which there is an option to tell STKO not to run regen on a parallel thread from scripts.

2) I am using Custom section and I enter the values of sectional properties manually for all sections. However, it seems that the graphical representation of these sections is totally off and they all appear very large, as shown in the screenshot below. This makes is almost impossible to use the model since I cannot see well beams and columns Is there any way to control the size of the section in the graphical representation when Custom sections are used?

The graphic representation of a custom section is a circle with the area you specify. Did you specify a very high Area to simulate a stiff element?

[kolozvari]

Hello,

I would like to build up on my elastic model of this moment frame building described earlier in this thread and create an inelastic model by adding lumped plasticity hinges. Since there are many hinges in the model, and they are located at different locations, I was wondering if there is any automation that I can use to create hinge properties and nodes, and assign spring properties to the newly generated nodes in the model? Otherwise, this seems like an impossible task.

Please let me know.

Thank you,

[STKO Team]

To clarify:
Do you want to use the BeamWithHinges automation in STKO? (it takes a beam element for the inner part and a zero-length property for the hinges)(You can model your beam-columns as a continuous frame and STKO will take care of creating extra nodes and springs for the hinges)

If yes, do you need a script to create uniaxial materials for Moment-Rotation relations and put them into zeroLengthMaterials? (to be used in the previously mentioned BeamWithHinges)

[kolozvari]

Yes! And to define the properties of the hinge materials and the beam with hinges element (e.g. location of the hinge).

Note that I already have a fully elastic model.

Please let me know. Thanks.

[STKO Team]

Ok, let's start step by step.

These are the components you need for a hinged-beam model:

1. a uniaxial material for the moment-curvature (what model?) for the 2 rotational (bending) DOFs
2. an elastic uniaxial material (penalty-like) for the DOFs where you want continuity
3. The zeroLength material wrapper (to put together material in points 1. and 2.)
4. The property for the inner part of the beam (Elastic section?)
5. The hinged beam property (to put together points 3 and 4)
6. The zero length element
7. The inner beam element (Elastic beam column?)
8. The hinged beam element (to put together points 6 and 7)

Please provide the models (just the class type) you want to use for points 1, 4 and 7

[kolozvari]

Hello,

Thank you for your response and your help. Please see below.

1. a uniaxial material for the moment-curvature (what model?) for the 2 rotational (bending) DOFs

HystereticSM

4. The property for the inner part of the beam (Elastic section?)

Elastic

7. The inner beam element (Elastic beam column?)

Elastic or Timoshenko (would be good to be able to switch between both)

Please note that I plan to model the beams and columns like this:

x---o-----o---x

x : beam/column end node
--- : elastic beam-column
o: moment hinge

it is important to be able to define the distance between the "x" and "o" (rigid panel zeon).

Thank you!

[STKO Team]

In this case probably it's better to create a new ElementPropery in STKO (it will always be a python script), but in this way you don't need to run a script every time.

If it's fine for you, we can start doing it.
We will need a list of input that this element (and its associated physical property will need).
For example, B, H, concrete strength, steel strength, steel ratio, etc..., and it will automatically create an elastic element for the central part and the external parts, and the hinges in the middle

[kolozvari]

Hello,

Thank you very much for your help. Yes, it is fine with me.

Here is the list of parameters that is input for the model elastic and inelastic properties:
1) Elastic section properties: Area, moments of inertia (Ix, Iy, Iz), Shear coefficients (Ky, Kz). Please note that most of this information was already implemented in the API you sent me earlier (see previous messages in this thread).
2) Elastic material properties: E, G, Poisson ratio, Density. Please note that most of this information was already implemented in the API you sent me earlier (see previous messages in this thread).
3) Nonlinear hinge information for beam compound elements including: a) modeled via moment-rotation relationships as this is a steel building (no reinforcing ratio needed). It would be great if each hinge could accommodate nonlinear moment-rotation behavior about both principal axes of the cross-section. HystereticSM or similar material can be used for the backbone relationship; b) parameter that defines the location of the hinge via either absolute or relative distance from the beam ends; c) option to add stiff zone of a certain length at the beam ends to model beam-column joint fixity.

The beam compound component would be:

x==--o-------o--==x

where:
x node
== stiff end zone
-- elastic section
o nonlinear MY-RotY and MZ-RotZ hinges

Please let me know if this is possible and if there is anything I can do to help.

Thank you very much!