[Karamba&Galapagos] Modeling, analysis errors, and questions

Grasshopper Karamba3D
1

So, I have a couple questions regarding the errors and problem I found on my model after I try to analyze them. (I’m learning how to model this truss from this video. And this is my file Design.gh (49.1 KB)

  1. I was trying to analyze my truss and I got the message error saying that I have 3 rigid body mode in the system. And I’m not sure how to fix this error.

    rigid%20mode
    rigid mode.png1112×122 6.99 KB

  2. When I added Model View component and connect my Model output from my Analyze component to the Model input in my Model View component, there are some lines appeared on my model. What happened here and how can I fix this?

This is what I expected it to be and before the model input/output are connected
truss1

After I connect them this is what happened

truss0
truss0.png508×606 7.55 KB

To tell you how big it is, I cannot even see my truss
truss2

  1. From the video above, he defined cross section separate from beam element and then connect it do Assemble Model component through Cross Section Case component, so I did the same thing. My question is how does grasshopper know which cross section goes with which element? I was thinking about connect the Cross Section output to the cross section input for each Line to Beam component. But then, in this case, the cross section input in the Assemble component will be empty, will this be a problem?

  2. After I connect the my model with model between Analyze component and Beam View component, why doesn’t it appear as beam in my model like in the video? How can I make it appears on my model as beams? @12:00

  3. I would like to minimize the deformation of my truss using Galapagos, I don’t see where I can connect my Fitness from Galapagos with the deformation on the Model View component. How should I done this?

  4. I would also like to applied distributed load onto the truss. I was trying to add a uniform line load from Load Karamba component but it seems like I have to apply to a specific element. Is there a way I can apply this load by specifying the global coordinates?

Thank you very much everyone!

2

Dear N Smust,

there were several problems in your definition (see Design_cp.gh (60.2 KB) ):

  1. The support conditions were not sufficient for keeping the structure from moving as a rigid body.
  2. The upper and lower girder of the truss were defined as one line each. In Karamba3D elements are only connected when they share end-points. Therefore the girders need to be subdivided before creating elements from them.
  3. Your cross sections are very small - is this on purpose? The input for the cross section dimensions is in centimeter. One gets this information by letting the mouse-pointer hover over the corresponding input-plug.

At the moment the truss consists of beam elements. When switching to truss elements by setting ‘Bending’ to ‘false’ make sure to apply sufficient supports so that the nodes can not move perpendicular to the truss-plane.

When connecting the cross-sections directly to the ‘Assemble’-component they get attached via element identifier (see the manual for details).

The maximum displacement is an output of the ‘Analyze’-component.

You can name elements via the ‘Id’-input-plug of the ‘LineToBeam’-component (e.g. all elements of the upper girder ‘upper’) and then attach a line-load to all elements of a given name (see the manual for details).

Best,
Clemens

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I don’t know what else I can say other than thank you very much. I really mean this. Just one more question, when you say manual, where can I find this manual? Again, thank you very much!

4

Get Started - Karamba3D scroll down to Resources, click View User Manual Version 1.3.2

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