http://www.grasshopper3d.com/photo/album/show?id=2985220%3AAlbum%3A...

some impressions of my master thesis which is based on karamba.
karamba was a great help.

Hi there! i had a problem installing karamba. I managed to install it eventually by installing it at "C:\Users\me\AppData\Roaming\Grasshopper\Libraries". I can see karamba now in grasshoper ,but i still canot use the assemble component. I instaalled karamba to other computers and it seems that when instaling it in the folder Program Files (x86)\Grasshopper for Rhino 5\ it seems to work completeley fine. The problem is whenever i instal grasshopper it never installs it on the "grasshopper for rhino 5" folder, so that folder does not exist. when i see the computers of some friends that location is the instalation folder for grasshopper. The thing is when i instal grasshopper there is no option to choose where it will be installed, so I dont know how to fix this. I have seen that others that had similar problems and tried to follow the instractions that where proposed, but nothing works still. Any ideas?

Hi Sofoklis, with the new versions of grasshopper (>0.9.0060 or so) and Karamba 1.0.4 you have to look up the installation folder of GH in Rhino (Tools/Options.../Plug-ins/Grasshopper - Properties). This is where Karamba 1.0.4 needs to be installed (and to where the installation path needs to be changed).

Sorry for the inconvenience. The issue will be solved in the next release of Karamba.

Best,

Clemens 

Hi

im a bit comfused. (And not with my sexuality)

How can I create solid rectangular cross sections which are normal for wood and concrete structures?

Hi,

use the 'Trapezoid-Profile'-component and set upper and lower width to equal values.

I have installed karamba1.04 for grasshopper 0.90064,why it doesn't show in grasshopper?

Did you change the Karamba installation target directory to where grasshopper.dll resides? Did you install Karamba-64-bit for Rhino5-64bit and Karamba-32-bit for all other versions of Rhino? Did you have a look at http://www.grasshopper3d.com/group/karamba/forum/topics/karamba-use... and http://www.grasshopper3d.com/group/karamba/forum/topics/help-reques...?

Best,

Clemens

Hi,

you mean I should install two karamba 32bit and 64bit, if I have both version of rhino in my computer?

Now I have rhion 4 and rhino 5 32bit & 64bit both. I installed karamba 1.04 for rhino 64bit free version in my grasshopper for rhino 5 folder, it does show in the grasshopper folder, but when I open rhino and grasshopper, it doesn't show on the tool bar and I didn't find the Draw All Components in Grasshoppers View-menu mentioned in the Karamba installation booklet.

I am trying to analyze the structural behaviors of a brick masonry vault and a masonry shell structure. In karamba there is no material property of brick masonry in the material list. How can I solve this problem?

Hi, maybe you find this helpful: http://www.grasshopper3d.com/group/karamba/forum/topics/masonry-str....

Best,

Clemens

The result of karamba analysis is too big compare with my grasshopper model even after I reduce the radius, can I change the unit of karamba to make it proper? I tried to look for the "karamba.ini" mentioned in the booklet, but didn't find it.

Thanks!

"karamba.ini" is located in the folder "Karamba" which can be found in the installation directory of Karamba.

Hi there,

long time no comments!

Dear Clemens,

This is actual proper that karamba have some rules for defining the relations between components, from points to lines, lines to surfaces, surfaces to forms and volumes and so on. except from manual which you've released before, is there any references you know, we could adapt our models to, for writing algorithms more accurate?

Thanks,

Mahdi

All examples files are restricted in trial version , how to test it ?

Dear Kaz, you can run the examples them with the trial-version by decreasing the number of elements or use the free version when only beams are involved. Alternatively I can send you a one-month trial license for the full version.

Best, Clemens 

it would be better to test full version , thank you for your cooperation , here is my email : blumen.sy@gmail.com

thanks again

Dear Clemens,

Could I enjoy that one-month trial license? I need to try beam joints components.

Thank you very much.

Hi karamba-team,

I couldn't find the exact solver type you are using for the global equation system, but I guess it's a direct solver since the computation time increases heavily when exceeding 30000 nodes on my PC. Do you plan to integrate an iterative solver like PCG or similar in the next releases that steps into place when the model gets larger? For my uses this would be a great asset on your already great program because in complex models I cannot reach a mesh-independent solution without killing my PC for many hours...

Thank you,

Robert

Hi Robert,

the solver currently used in Karamba is a direct solver.

Did you check the memory usage when computing your model? If the machine runs out of physical memory it starts to use the hard disk which makes the solution process very slow. 

A PCG solver would be a good idea. Maybe I find a good one for the next release.

Best,

Clemens

Hi All,

I am trying to create a parametric 3D framed structure, although am struggling with the error "singluar stiffness matrix: cannot solve static problem" at the analyze model stage. Any help would be greatly appreciated. Here is the GH file grasshopper%2011.gh.

Hi Felicity...this would be better on the discussion forum than here. But it was because your vertical members weren't broken down, they were all one element. You needed to break them down to intersect with the horizontals. See attached for a method of doing this (disclaimer - there are probably slicker ways of doing the intersect). I believe the model runs now. grasshopper11_jjs.gh

Thanks! I will make sure to direct any further queries to the discussion forum, but my many thanks for getting it working :)

Dear Huax,

I tried out your file but could not reproduce the error. Du you use the latest version of Karamba?

Best, Clemens

Dear Huax, did you try to evaluate the eigen-modes of your structure? The first eigen-mode shows how the structure moves as a rigid body in case it is kinematic.

Best, Clemens

P.S.: Would you mind opening a new discussion on the subject? It would be better readable for others.

8-10-14losa.gh

hello, I'm working on this model. I would like to know how to connect the slab with beams, so that the whole work as one element.

Thank you

Hello Patricio, divide the beams in such a way that each boundary vertex of the shell becomes an endpoint of a beam segment.

Best, Clemens

Hi Clemens,

I did what you suggested but now assemble element doesn´t work properly. Could you please tell me how to fix it? Thanks in advance, Patricio

8-10-14losa%20cadena.gh

Hi Patricio,
if you flatten the 'Elem'-input at the 'Assemble'-component the definition works. The triangular shell elements have linear displacement interpolations whereas the beam deflections are exact. In order to get correct results you should refine the shell mesh.

Best, Clemens

Hello, succeeds in creating the mesh to the slab, and built the beam segment, but when I see the deformations are not expected because the beam is deformed as the slab.

Thanks for the help

PS: maybe I'm using the program for a type of structure that is not the most appropriate, as I saw in the examples of other structures. But this type of structure is that students taught

best regards

Patricio

9-10-14%20Example%201.gh

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)