Effectively thats right. If you have two pins in the same support plane then the second pin will restrict the model from utilising the rollers.

Restraint conditions are, in my opinion, one of the trickiest things to understand when you start modelling.

Dear RubberDuck,

Christoph will make a separate assembly of the custome components and publish it on Food4Rhino. But this may take some time.

Clemens

I have set up this model for a Cantilever with a 2kN point load. Displacement is 72m for a 30m CHS 100x3.3. I then set up the same model in SpaceGass and get the following results:

How do you calibrate your models? I am just trying to work it out so I can start using this for my paper on parametric structural analysis.

Hi Joshua - I think part of the problem with your Karamba model may be the document accuracy - If you have a document with [m] units the tolerance is only +/-.001m by default in Rhino; Grasshopper uses these same tolerances.
The theoretical deflection of your cantilever beam is 

delta = P*L^3/(3*E*I)

= (2000 N) * (30,000 mm)^3 / (3*205000 N/mm^2*1173164mm^4)

= 74,844.5mm

So in your image below Karamba is slightly out, but your SpaceGass model is somehow much different or wrong - have you checked your material /section properties?

I did a quick model in Karamba with the document in [mm] units and got a deflection of 73,062.5mm which is only a 2.5% difference from the theoretical answer.  I did a quick model in Autodesk Robot as well and got exactly 74,844.5mm deflection as expected.

Haha good timing Luke!

I am writing a paper on Parametric structural analysis and just ran through all my analysers to see where I went wrong. I have it pretty much the same.

Example - CHS 100mm x 4mm

Deflection Calcs:

Manual - 64.6m

SG - 60.6m

Karamba - 61.5

Egret - 74.3

Now I am CERTAIN Egret is a result of a bug (I sincerely doubt Jon has made an error and it has been playing up on my computer probably because its full of shit).

I ran another model at 50mm depth of CHS to see if they maintain similar ratios. They do. I wanted to check that I could use Karamba and Egret for Galapagos modelling, so they are both pretty good.

Thank you for the check, its good to have a second set of eyes on problems like this.

Karamba uses a Young's Modulus of 21000[kN/cm2] and by default the thickness is 1/30 of the diameter of the tube. For D=100mm this results in t=3.33333 (etc.).

If you set both values according to the hand-calculation below you get the exact result of 74.844504m.

Here the definition:

Hi Josh,

Thanks for the confidence, but I would certainly double check anything computed by Egret (I haven't had the time or opportunity I'd like to progress and validate it).  I did quickly set up your verification model, the file can be downloaded here:

http://www.grasshopper3d.com/group/geometrygym/forum/attachment/dow...

I would suggest updating Egret from http://www.geometrygym.com/downloads , if you do, you should also see a deformation of 74.844504 (my gh definition assumes mm rhino document units).  If you want to send me the spacegass model, I'll take a look at it for you.

Ok here are the modules I have used to verify.

Karamba Cantilever

Egret Cantilever

I just built the same model in SG:

30m Cantilever

Incaste

2kN point Load at end

And drew the section in the section creator based on the Chinese steel manuals (S235).

Any update on when the learning examples will be available? I feel like I just cant set up my modules right.

What type of accuracy or units do people work in for their Rhino file when they work with karamba?

Here is some WIP to share:

Portal Frame Model

Portal Frame Model w/ Galapgos

CSV File for Sections

Deflections are not right at the moment but will sort them out tomorrow. Pretty happy with the models behaviour.

Having some trouble getting a pinned truss to perform. It works if I allow the beams to bend but when its pin jointed it doesn't like it. Any ideas?

Arch%20Truss%20Karamba.gh

Is it because its trying to be pin jointed at the roller and pin supports? If so how do I remove that?

Beams with bending switched off transmit normal force only. A node that connects to such elements has three degrees of freedom. In case of a planar truss add out of plane supports at all nodes (see also subsection 'Bending stiffness' of section 'How to change beam properties' in the karamba manual).

hey guys!

i want to try karamba example out of the manual, but analyze component turns red...

do you have any ideas where the problem is?

it would be nice if you could help me!

Remarkable new version, very exciting developments.  Keep up the good work!

I love the new version, too.

I am especially interested in the feature: "Free-form structure under uniformly distributed loads - optimized cross sections and bending moments:" shown on the last image above. Is this a new feature?
How to automatically apply that uniform load to a free form structure?

Hello Najna,

you can use the MeshLoad-component to automatically generate point-loads from distributed loads.

Is there a plan to make the sectional profiles visible ? currently they all appear to be tubes ?

I-sections should appear as I-sections, Boxes as boxes,...

Please post your definition in case karamba behaves differently.

Best, Clemens

Absolutely great piece of work. I combined it with galapagos and it solved my problem in minutes! That was a 2 day work to export to Sap2000. Thanks for your beautiful work :)

~Moe

I am using Karamba for structural analysis and optimization.  I've  been moving my GH components over to Rhino 5 and I'm having trouble with the Analysis component.  Here are the steps I've gone through (3 times now).

1. Install latest Rhino 5 beta 64-bit.  Keep old Rhino 4 install.
2. Copy over GH component files from Rhino 4 since you cannot specify the install directory when installing GH.  Add GH as a plug in for Rhino 5.
3. Install Karamba Free 0.9.083 to Rhino 4.  I tried to install Karamba to Rhino 5 beta (under C:\Program Files\Rhinoceros 5.0 Beta (64-bit)\Plug-ins\Grasshopper\Components) but when I install no files appear in the directory.
4. Copy all Karamba files to Rhino 5 directory.

5.  Start Rhino 5 and GH.  Karamba appears in the toolbar and everything appears fine, but I receive the below error from the Analysis component:

Error: Solution exception: The type initializer for 'fem.karambaPINVOKE' threw an exception.

Response from Karamba:

Karamba works on Rhino 32bit. It doesn’t do so for the 64bit-Version because the calculation core is a 32-bit-dll.

The next version of Karamba will work on 32 and 64-bit machines.

hi @ll,

i have some probs with opening the example files.

e.g for LargeDeformationFormFinding_1.gh

maybbe you could ubdate - big thanks !

The archive contains an unrecognized object: Line to beam (karamba) {761b7152-1fb9-4b23-af3c-918d9c889da8}

This object cannot be deserialized

The archive contains an unrecognized object: Large deformation analysis (karamba) {346a8101-b0f3-4d61-b0e0-e85cdeb9d289}

This object cannot be deserialized

The archive contains an unrecognized object: Assemble Model (karamba) {fcd0a5ca-c3e5-433b-a2ad-ba41365116fd}

This object cannot be deserialized

hey

i did dl the latest version of karamba @ your old site, so that was outdated . with new version by http://www.karamba3d.com/ it works

thanx

Support Conditions in Karamba

Few months ago, some member posted a preview of the Support Conditions in Karamba. Take a look:

I saved that image, but did not really understand it.

The black round circles, represent the option that should be checked? And what about the white circles? What do they represent?

Also the last part - hinged connections of the truss, I do not understand it. How to achieve the hinged connections among truss members?

Thank you.

hey djordje!

Tx, Ty, Tz represent the freedom of a support to move  in x, y and z direction (T for translate). the same holds for Rx, Ry, Rz but for a rotation around the respective axis.  those directions can also be determined by a reference plane other than the world xyz system.

Black means the degree of freedom is restrained, while white means it is free to move.

the symbols you see in the drawing are possibilities to more apparently visualize a special support situation, e.g. having a member on a rolling wagon etc..

you could also post requests in our discussion forum http://www.grasshopper3d.com/group/karamba/forum rather than on the board ;)

best

ah,

and hinged connections you can achieve either by using the 'modify beam' component and set the 'bending' input to false, or specify it more detailed by introducing 'cross section joints' on specific beam ids where you can set the same properties as for supports for each the start and the end node of a beam separately.

Hi all, where can I find the mkset tool, or where can I get it? I am experimenting with the stitching tools for trusses and need this tool to stitch a number of truss tension members to their corresponding compression member. 

Thanks

K?

it's in the 'Ensemble'-section.

Best,

C

I still cannot find it, do I have a wrong version or is something disabled from layouts?

Thanks K

The component is missing due to an error in my compiler settings. I have sent you a corrected version.

Best,

Clemens

Please send me your machine.id file: Put a license component on the canvas, right-click on its icon and select 'Save machine.id' from the context menu.

Best,

Clemens

Hello,

I`m using karamba for my shell structure. With the analyzis

the displacements are given, the princ. stress do not work, how can

i solve this problem? See the pictures

I get the messages:

Error: Solution exception: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

J. Koeken

Just asked a stupid question, hadnt realized that rhino 4 was 32 bits and was trying to use Karamba 64.

Is it possible to create UPE cross sections [   -  to be used in karamba?  if so can I edit the csv file for cross sections to create my own table, for custom sections?

Hi Kane, it is currently not possible to use [-cross sections with Karamba.

In such cross sections the center of gravity and the center of shear do not coincide. The necessary algorithms to take that into account haven't been implemented yet in Karamba.

Best, Clemens

Hi.

After using Karamba3d for a while, I came to think:

What does Karamba stand for? Any idea behind the name?

Hi,

it comes from the Spanish word caramba; the main source of inspiration was Bart Simpson.

Best,

Clemens

Hey all,
i wana simulate the Dome reactions to the pressure included form -Z pressure, what is your best solution for defining the set of point for support and how can i find the way out of run time errors when i want to analyze this model?
would you mind trying it on this definition and send me back?
my pleasure,

Dome%20gh.gh
Dome.3dm

Hi Mahdi,

missing :

-cross section

-material

-identifiers

-bad mesh (mesh with Mesh/Utils/Mesh Brep)

-points

find the modified file :

Domegh%281%29.gh

Best regards,

Michel

Simpsons: AY Karamba... Not sure how I will explain that to my supervisor... haha. Nice. 

Hi,

I am working on a customised component with Visual Studio (vb.net).I would like to add radio buttons on the component, like on your Karamba Support Component. Could you explain how to do that ? I saw you were using MenuRadioButtonGroup, but this type is not recognized. Which extra reference do I have to import to have access to this ?

You you need to add a reference to karamba.gha.

Best,

Clemens

The user-interface widgets are part of Karamba and not yet available separately.

Best,

Clemens

How can I add a .gha reference with Visual Studio ? I can just import .dll, .tlb, .olb, .ocx, .exe and .manifest

Add karamba.dll (which is the wrong file) first. Then use a text editor on the MSVC .sln-file and change karamba.dll to karamba.gha.

Best,

Clemens

OK, I renamed .gha to .dll and it worked. Thanks a lot !

Last question : did you developped yourself all the classes needed to add radio buttons or, was it already available ?

The classes were developed by Christoph Zimmel.

Best,

Clemens

How can i define joints in my models?

regards