Karamba for advanced timber analysis

Hello,

I am a PhD student and I carry out research in tall timber buildings. I like the working interface of Karamba/Grasshopper and the speed of calculation of the finite elements by Karamba (the reason for this impressive speed is another good question if you can answer).

Before I embark into a Karamba adventure I need to ensure that I can do everything I need with the software, and after playing around with a simple structure the default components are not really convincing me. The potential for scripting stuff into it however sounds like a solution and I would like to know if anyone in here has succeeded in modelling the following:

  • Accounting for the anisotropic behaviour of timber as a material (not enough material parameters given in the inputs), or engineered wood product properties, like Glulam and CLT.
  • Creating iteration loops, for example for Monte Carlo Simulations (that could be scripted I am sure).
  • Accounting for material non-linearities, for example by inputting a stress-strain graph instead of a single value in the rotation stiffness Cr of a hinge.
  • Accounting for dynamic effects when it comes to sudden changes in a system, for example the speed of a forced displacement, or removal of a member or support.

If you have managed the above, please do let me know. I just want to know if they are possible and if they are, is it worth it? My other options are of course Matlab, RFEM, Robot, etc.

Many thanks in advance,

Konstantinos

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Hello Voulpiotis,

in Karamba3d 1.3.0 it is possible to define orthotropic materials for shell elements. There are no spiecialized marterials for Glulam and CLT however.

The creation of iteration loops is possible via the GH scripting component.

Material non-linearity as well as transient dynamic analysis are not supported in Karamba 1.3.0.

Best,
Clemens

Voulpiotis,
Often people us Karama/Grasshopper to create the base models and then export using Geometry Gym’s components or similar to GSA, Robot, SCIA, Etabs.

This allows them to use the parametric nature of grasshopper combined with the loadings thru karamba then use preferred finite element program to finish the analysis.

Thanks Tim and Clemens. I will have to see how that GH/external FEA interface works. What is really nice in keeping everything in GH is that I see the changes live.

What I am trying to do is basically a reliability analysis on GH. This involves iterative simulations with random variables and can be carried out, as far as I understand, very well with Karamba and some scripting, but only for linear, static, isotropic material assumptions.

Yes agreed, your statement would reflect my understandings.

Hey- Just curious on the outcome of this. Did you have any success modeling and analyzing mass timber elements in Karamba?

Hi Kristina,

Not started yet! Lately I have been busy with a million things (#PhDlife) and pretty everything other than modelling…

Any news on your adventures with Karamba and Timber? I’m also starting to research the topic, if someone has some interesting findings.

Hello everyone,

@voulpiotis @admeirel

Did you have any progress in this direction?
I am also trying to find a way to optimize the use of mass timber.

Best,
Daniel

Hi Daniel,
My current focus in modelling is implementing nonlinearities via Abaqus and Matlab. I use GH to create and translate geometry to .txt files so that Abaqus and Matlab (and in fact any other software) can read it and run it. This works well for me - but I haven’t looked further into having all these features ready in a GH package.

Hi Konstantinos,

This is really interesting! Were you able to create some kind of feedback loop with GH? I mean, modifying the geometry based on the results of another software.
I started with RFEM and a friend is trying with sofistik. Did you try them?

I see a promising future in this line of research.

I haven’t tried that, no. Would be great for iterative geometry optimisation - if you have an idea on how to do this with GH, please let me know!
Regarding RFEM: I don’t use it since it lacks the sophistication I need which is available in Abaqus, but it is a great software for less demanding models (most industrial applications) and the newest version has a GH plugin, have you checked that one out? Still pretty basic, but a step in the right direction for sure.
Sofistik, I haven’t tried that.

Hi all, there is a new plugin Beaver, which looks into design of Timber structures according to Eurocode 5 based off Karamba3Ds core. You could check it out to see if it helps.

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@voulpiotis @daniel.locatelli @tim.messer
I am very interested in modeling and analyzing CLT elements, also known as XLAM. Are there any updates after these posted messages? Would you like to share them or compare them with me?

Hey Monica, my thesis had a slightly change of focus. We developed a building system based more on CLT fabrication and transportation constraints than in structural analysis. We will release the results soon.

How far did you get?

Did any of you develop further on any plug-in or tool to perform an analysis on CLT in GH?