You could use the 'Mesh Edges'-component to retrieve the naked edges and turn them into beams - see attached file: 91014Example1_cp.gh

Best regards,

Clemens

Perfect, that is just what I needed, thank you very much for your help, I'll keep working and any questions write again, it is very useful for students to understand the structural performance.

best regards

Patricio

Dear clemens

I was doing a rough estimate of the deformation, and I can not achieve the same result with Karamba.
When I make a rough estimate of the result with Karamba beams and mine are very similar, I think the problem is when I connect the shell, because there are no similar results.

I sent the GH file, and an image of the calculation

The structure is concrete
The result I get is 0.58cm

thank you

Patricio

15-10-14%20Example.gh

Dear Patricio,

try to increase the number of shell elements. As mentioned in the manual they are linear elements. A mesh that is too coarse leads to a response which is stiffer than the real structure. 

Best,

Clemens

P.S.: Could you please open a new discussion on the topic? These discussions are easier to find and follow for other people who face a similar problem.

Dear clemens

Thanks for the help, I just created a topic discussion and add any comments that we have done so far.

Best regards

Patricio

Hi Clemens,

I need your help! I have a very simple curved geometry, like an arch, composed by several beams. This is a not funicular geometry and there are huge bending moments. I do not understand:

1) if the Cross Section Optimization component takes into account buckling for members in bending and axial compression (6.3.3 - Eurocode 3).  

2) if the buckling length corresponds to each beam or to the length of the whole arch or to the distance between supports (local or global buckling.

If instead of an arch, there is a more complex structure, i.e. an arch bridge with tendons and deck, what is the buckling length of the arch adopted by the Cross Section Optimization component?

Many thanks,

Leonardo

Hi Leonardo,

the Cross Section Optimization component takes into account buckling for members (see the appendix of the Karamba manual). The assumed buckling length is the distance between two nodes that connect to more than three beams or to a support or double that distance in case one end is free. The buckling lengths can be set manually via the 'ModifyBeam'-component.
If you have 'huge' bending moments in your structure then buckling will have little effect on the result. 

Sometimes so called global buckling can govern a design (think e.g. of a compressed girder of a truss structure). In such cases one has to guess the buckling length or do a buckling analysis (which will be possible in Karamba 1.1.0). 

Best,

Clemens

Clemens, thanks for your quick answer.

I have carefully read the appendix and the way for calculating the buckling length is clear. However I have still one questions:

seems to be that adopting Eurocode3 (eq. 6.47) only the normal forces are compared with the critical buckling load. Am I right?

Can we want take into account both, bending and axial compression, as suggested by Eurocode3 (Eq. 6.3.3)? 

Many thanks,

Leonardo

Leonardo:

in Karamba 1.0.5 the cross section optimization algorithm only considers normal forces for buckling. The next version (Karamba 1.1.0) takes full account of the EC3 formulas including lateral torsional buckling and interaction values according to annex B.

Best,

Clemens

Hey guys! do you know where to find the "point-load" component in the latest version of Karamba? thank you for your help

Hey guys, I'm having two issues.

Is there any way to change the eccentricity of the post-tension load? I changed the ecce-loc input but that only changes the centroid of where the point load acts -- the post-tension load seems to be unaffected.

2. How do I get a filled trapezoid cross section? It appears to be hollow at the moment. 

Thanks for your help in advance!

Hi Elisa,

in Karamba 1.1.0 the post-tension load is attached to the eccentric beam element (see PreTensionLoad_EccentricBeam.gh).

The trapezoid cross section is filled (when rendered it looks hollow though). The box cross section is hollow.

Best,

Clemens

Clemens,

Thanks for your response. However, I'm still having trouble with the ecce-loc. I want to change ONLY the eccentricity of the prestress load , and not offset the other uniform loads. Is there a way to do that?

Elisa, you could try to place two elements in the same spot. One with, one without eccentricity and add corresponding loads to them.

Best, C.

Can curved folding simulations be done using Karamba?
Something along these lines :

What I don't get is why in the simply supported plate and beam examples one of the ends doesn't move horizontally when the beam/plate gets bent.

It does have the freedom to do so and in order to keep the length constant it should do so, yet it doesn't. Please answer if You can

Clemens,

What do you mean by placing two elements in the same spot? Wouldn't that give me two separate beams? 

Hi all,

Is there a way to move supports by a certain distance in a certain direction?

(say i have a shell and i want to move one of its vertexes and see what stresses appear)

Hi Andrei,I guess you would need to move the point that defines the aforementioned support in order to do that.

Best,

Rafael

Hi, Rafael,

The problem with this method is that the model won't consider internal stresses. The moving has to take place after the point is converted to a support variable.

Hi Andrei, have you had a look to the "prescribed displacement" component? I guess this one will help you out with what you want. cheers, Rafael.

Hi, Rafael! I did, but i didn't manage to get what i wanted. I used the prescribed displacement component with an input vector and a force acting on the points of the prescribed displacement hoping that once the amplitude of the vector is reached, the points don't move any further, but they di surpass the length of the vector...

Dear all,

in case of questions please open new discussions (see above). They are easier to find and to follow than entries on the comment wall.

Best,

Clemens

New tutorials showing workflow between Karamba and Revit using Geometry Gym and Dynamo are up on our youtube and Grasshopper pages! The full definitions will follow shortly!

Hi all!

Karamba 1.2.0 is now available! The latest release contains a new solver that is twice as fast and uses less memory. New components such as the BESO for Shells and Deformation Energy have been introduced. The entire list of updates and bug-fixes can be found at http://www.grasshopper3d.com/group/karamba/page/new-features-and-bu.... Look out for some new examples coming soon.

It can be downloaded from our website or from food4rhino. Enjoy!

Your Karamba Team

Hi All!

does anyone know how to make this kind of image?

I saw different image like this made from Robert ( Hi Robert ) but I wasn't able.

Best,

Marco

Hi Marco,

the image is similar to the setup in the example on our website. You can adjust the element felting settings to and add additional parameters to achieve different results.

Matt

second order theory (Th.II) could you pls help me understand what this theory is called in Italian? is Karamba ok to do the analysis in Italy? 

Hello Alexia, Karamba is a Finite Element toolkit and thus does not depend on national specifications. The only exeption is the cross section optimization algorithm which is based on Eurocode 3.

If I use the last version of Karamba and I need to know the best sections of the beams do I need to use galapagos or is it ok to use the option of the best beam?

Hello Team Karamba,

I am new to Karamba and have just purchased a PRO license (waiting for activation).

I am currently working on Voronoi Gridshell structures for my Master Thesis  and came across a very relevant example on your side. The example is http://www.karamba3d.com/examples/hard/projected-voronoi-pattern-gr....

I am very interested in knowing more about it. Is there any related tutorial ? (i could not find any on the site)

Kind regards,

Balaji

Hi Balaji, we currently do not have any specific tutorials relating to voronoi gridshells, but there are some tutorials on gridshells themselves. Otherwise I am sure there would be a wide range of tutorials in the wider grasshopper community to guide you through setting up a voronoi gridshell.

Matthew

Hi Matthew,

Thanks for the answer!

Yes, I actually do have a Voronoi Gridshell in Hand, made by myself but the Thing I am looking for is to optimize it (moving the seed points) according to the boundary conditions (loads), which made me stumble upon Karamba.

Do you have any closely related stuff?

Balaji

Hi Balaji,

Although we don't have any tutorials relating to voronoi gridshells, the following tutorial explains how to set up a generic gridshell. You can use the same technique to apply it to the voronoi grasshopper setup.
http://www.karamba3d.com/tutorials/tutorials_basics/analyze-a-grids...

Please note that most of the tutorials on our page are not set up by us and rather other users who have been kind enough to share them with us.

Hello Team Karamba,

I am relatively new to Karamba. I was wondering if Karamba can deal with pretension problems, or support settlement problem where the initial displacement of certain amount takes place that causes forces developed in the truss or frame members. 

Kind Regards.

Hello Earth,

use the 'Prescribed Displacement'-component and 'InitialStrain' from the 'Loads'-component to define support settlements and pretension in elements respectively. For details see the manual. It can be downloaded from http://www.food4rhino.com/ or http://www.karamba3d.com/downloads/. Please open a new discussion in case of further questions.

Regards,

Clemens

Hello:

I want to know how to make a program and analysis the structure of shell waffle covered with the steel plate.

I want to create the load for the steel plate(6 mm thickness) to check the displacement of the waffle structure.

I uploaded the schematic diagram and part of the program. Any suggestion? 

Please help me.

Thank you very much

Ma

ma20170129.gh

Hello Qinsong,

Do you have the steel plate mesh? If you do so you can use the Mesh Load component, setting the vector force to global in negative Z direction (the amplitude of the vector will be the mesh load (kN/m²).

In the component you can set the points of the mesh witch the load will be accounted, try to insert there only the upper nodes of your waffle structure.

Márcio

Hello Márcio,

Hello Márcio,

Thank you for your answer.

Normally I have done as you said. But it's no relate to the thickness of the steel plate. I want to change the thickness of the steel plate to check the displacement of the waffle structure. I uploaded the part of the program. Could you help me finish the program? Thank you very much.

ma20170129.gh

Hello Qisong,

See attached the changes I made. To parametrize the thickness of the plate you just need to multiply its material density with the thickness (going from kN/m³ to kN/m², or just from volume to surface load).

ma20170129.gh

Dear Márcio:

You are very friendly. Thank you so much.

I'm sorry about that I did not describe the problem right. My English is bad.

I means the waffle structure and 6mm steel plate are Welded together. They become the overall structure, and I give the strong power to the overall structure to check the displacement. As it is shown in the image, the green plate is the steel plate, the yellow is the waffle structure. The overall structure is the waffle structure and steel plate are Welded together. How to analysis? Could you help me finish the program again?

Thank you very much.

Hello everyone! 

I'm doing my final project to graduate in engineering. What I'm trying to project is a footbridge that sail along the coast supported with puncheons. I am new in Karamba. When I considerate loads I had problems how to considerate wave, wind loads and the deck weight. how can I simulated all these loads?

bordo%20linea%20strada.3dm

FootbridgeKaramba.gh

Dear all,

could you please add a new discussion in case of questions? Postings on the comment wall are hard to follow and not easy to find by others.

Best,

Clemens

Hello Silvia,

For deck weight you should model a mesh of it and add a Mesh Load component including the nodes you want to consider (See Karamba manual for details, also in the previous comments I helped ma qingsong with a similar problem).

For wind and wave analysis you should first check for the structure vibration modes (For wind the first frequency should be >1.5Hz, i'm not sure what frequency band you need for waves). Grater stiffness and less mass helps to increase the frequencies. Once you achieved those results you can make a statical analysis considering these loads, again i'm not sure what to do for wave loads, but for wind I normally use the method used in this video: https://www.youtube.com/watch?v=-t3yE1xxMUo (it's a very simplified method, but do it's job).

I can take look on your GH definition tomorrow.

I going to have a look! thank you Marcio Sartorelli! I have added a new discussion for my problem as Clemens suggested! I will write you under my new discussion later

Hi!

I just downloaded Karamba trial about an hour ago, and I cant get going with my model. I have an interlocking structure (eggcrated, see picture: there is an error in that the long beams should rest on the arcs, not the other way around as it is now) that is to be glued together. How would I set up an analysis like this? 

Hi Martin,

you could use short connector beams with corresponding joint definitions at their ends.

Please open a new discussion if you want to discuss the matter further. The comment wall is not so well suited for that.

Best,

Clemens

Hi all, is it possible to run 100 karamba analysis automatically using different values of variables? and record the results? Thank you.

Hi Earth, if you wish to run multiple analyses automatically, you can look at either optimisation processes such as Galapagos or Octopus or you can simply use a Data Recorder to record your results.

Best,

Matthew