A simple definition using the 'BESO' and 'resulting element forces' - components of the latest release to evolve a topology and get evenly distributed axial stress.

is this addon something like sap2000 component? for frame structure ?

thanks for your reply.hope it will be as powerful as the general fea software, such as sap& midas. good job. i am learning it now.

Hello David, we will update Karamba as soon as possible.

I was wondering if Karamba can identify a compression members in a truss/space frame?
Is there a Karamba definition that will allow me to identify the compression members for any kind of truss or space frame?

For example, I want to select my truss/space frame from Rhino, then define the supports, nodal forces and some other parameters too, and then Karamba definition will allow me to get all members under the compression to be selected.

Can this be done in Karamba?

If it can, can anybody help me with it please?

Thank you.

Hey Najna,

this will do it:

... assuming you already built up your model. Your question was hypothetic? Karamba gives a multitude of results, including the ones you asked for. It also includes a BESO-designer considering the characteristic 'force' of your choice (bending, normal force, deformation energy...), and in the new release (to be available in the next days) also a 'Tensile / Compressive -designer' where you can set tension-only or compression-only elements (this technically also, like BESO, means a solution has to be found iteratively by the system).

Best, Robert

Thanks Robert :D

The solution you presented in the image means, that I need to add the parameter "curve" on the beginning of the your definition, then right click on it, "Set multiple curves" and select my whole space frame structure in Rhino. Then on the end I need to add the "data" parameter, which will gather all my members under compression?

Like this:

What about the supports and the nodal forces? How can I define them?

By the way the solution you presented is the one that works with Karamba 0.9.06? Karamba 0.9.06 is not compatible with Grasshopper 0.8.0051?

I have no problem in using your solution. Just I am curious: what will be benefits in using the solution in the newest Karamba in comparison to this one?

It's a little bit more. There are sample definitions for download at http://twl.uni-ak.ac.at/karamba/ that basically should provide what you need.

The new release also will contain better learning examples.

Here is a sample structure under self weight:

The green lines are the ones under axial compression.

cheers

Thank you Robert.

The last image you provided is from Karamba 0.9.06 or from the newest version that will be released in few days?

So basically I need to right-click on "Line" parameter, "select multiple lines" and select my whole space frame/truss structure in Rhino?

Then I need to right-click on "Point" parameter, and define the points in Rhine, where the supports will be.

And that is it? What about the nodal forces and choosing points in which they will be taken?

The sample files you mentioned are simple .ghx files. I think we need some sort of at least pdf tutorial or video for Karamba analysis.

I installed newest Grasshopper 0.8.0051 and newest Karamba 0.9.07.

I created the .ghx defintion the way you told me, but for some reason, my deformation does not look like yours. Take a look:

Can you help me? Where am I wrong?

Here are both .3dm and .ghx files:

Hey Najna,

the scale of your structure and the profiles don't match up. You either have to increase your profile heights with 'modify beam' component between 'line to beam' and 'assemble' or scale down your truss.

Hope you get where you want :)

Nice set of components. Could you tell me how you managed to add the drop down option box to many of yourcomponents? Im currently trying to release some components for Excel and the ability to use a dorp down box for optional settings would really stream line my components,

cheers

Thank you for advice. It worked! :)


The thing I am confused now, is the far left member. For some reason, the karamba does not treat it, nor as a member under compression, nor as a member under tension.
Why is that???

I see now. I have a "null" member. It has no force in it.

Sorry for disturbance.

Simple%20Beam%20Karamba.gh

Building a basic model to calibrate for a paper I am working on. I noticed that the length can cause issues with the model results. When it is set to 40m on the first slider, it doesnt work. Then set it to 39.75m and it works. This happens across the whole slider range at random points.

Have I missed something?

J

Thank you for the tip Joshua.

So If I want to lean my space truss on:

2 supports, I need:

1 pinned and 1 roller support?

3 supports, I need:

1 pinned, and 2 roller supports

4 supports, I need:

1 pinned, and 3 rollers supports

5 supports, I need:

1 pinned, and 4 roller supports

...

?