First big steps - cross section optimizing

Hey folks,

Id never thought i would need karamba, but to rebuild the ZOB in Hannover, Germany it would be the easiest way. I thought i create a planar grid of steel cross sections and apply loads to get the hogging moments. Than creating new cross sections depending on the moments at the specific point. But unfortunately iam not even able creating a simple grid.

Can someone help me?

Thanks

See attached file

Attachments:

ZOB.gh, 31 KB

Replies to This Discussion

Permalink Reply by Karamba3D on September 15, 2016 at 3:21am

Hi Hendrik,

you have to make sure that the lines are split at all the intersections otherwise karamba does not recognise that the beams touch. This is the reason why the karamba cannot recognise that the supports points are included in the model geometry. I used the line-line intersection component that comes with karamba to do this.

I am not sure what you wish to use the large deformation component for, but you need to ensure that the load case is set to 0 for it to work. To optimise the cross section sizes, you can use the cross section optimiser tools. There are various example definitions on how to use the cross section optimiser.

Matthew

Attachments:

ZOB_fixed.gh, 31 KB

Permalink Reply by Hendrik on September 18, 2016 at 10:58am

Hey, thanks for your reply!

I tought this might be the problem, thanks!

And the largest deformation was only left from other studies.

My new Problem is, that i want to change the hight of each beam depening on the My Moment at the beginning and ending of each beam. So, optimizing the crosssection as your command BUT like a flowing course in itself like in the picture, you now what i mean?

And btw, i know, karamba ist developed by Bollinger and Grohmann, so maybe we can discuss in german?

Greetings

Permalink Reply by Karamba3D on September 19, 2016 at 1:23am

Hi Hendrik,

its better to communicate in English so that non German speakers can also contribute and read the discussions.

To create the cross section heights according to the My moment you can use the results from the Beam View (Section Forces tab) component to set the heights. You can take a look at the example 'Cross Section Heights from Moments' which does exactly this. If you want to make it more organic like in the picture you would need to use some grasshopper workaround to smoothen the cross section heights.

Matthew

Permalink Reply by Hendrik on September 22, 2016 at 9:50am

Hi Matthew thanks for your advice!

I tried a bit with the definition you gave me from your homepage.

The only thing i have to do now is to get smooth polylines form the edges of those surfaces but this is not possible i guess, i mean for me.

Maybe you can have a look? As a early warning: the working time is a bit high, so dont wondering. :)

Thanks,

Hendrik

Attachments:

ZOB_fixed.gh, 38 KB

Permalink Reply by Karamba3D on September 26, 2016 at 8:55am

Hi Hendrik,

We have just published a new example where the beam heights are 'smoothened' according to the moment heights similar to what you are looking to achieve. Of course this is just one method of achieving this and there are other ways to do this.

http://www.karamba3d.com/smooth-cross-section-heights-from-moments/

You can refer to this example and then extract the parts for your own definition.

Matthew

Permalink Reply by Hendrik on September 26, 2016 at 1:39pm

Hi Matthew,

thanks for your reply. I dont know if i missclicked anything, the only result i get is not smoothed. And when i open the file there is one error message saying "unrecongnized objects - aligned dimension". Do i have to have any plug-in?

Hendrik

Permalink Reply by Karamba3D on September 27, 2016 at 2:16am

Hi Hendrik,

that is strange there are no other plugins used in the definition except for Karamba 1.2.0 I am not sure what is causing this issue. However you can follow the setup with your definition to achieve the beam heights in your own definition.

Matthew

Permalink Reply by Hendrik on September 27, 2016 at 6:05am

Ah, okay this would be the problem.

I installed the newest version now and there are no error messages. BUT my License was set from Pro Student to trail version. Now its unpossible to do anything, where is the License gone?

Hendrik

Permalink Reply by Karamba3D on September 27, 2016 at 6:19am

It might be that the license has been overwritten. You can just use the same license that you sent you when you purchased the student license.

Matthew

Permalink Reply by Hendrik on September 27, 2016 at 6:49am

Okay, i solved the license problem, but now, i think the result of the file is not correct. I didnt do anything and this is what karamba is showing me.

Can you show me wich of those command i have to enable preview to see the smoothed curves?

Hendrik

EDIT: I solved the Mesh problem, but the result is the same.

Permalink Reply by Karamba3D on September 27, 2016 at 7:01am

It seems like there is some issue with your definition that you downloaded. Do you know which version of grasshopper you have? Because there are supposed to be expressions from the Mesh from Points component (x+1).

The 'smoothed' beams are in the on the right side at the top. You will see that it is straight lines which give the impression that it is curved. However if you each piece to be curved then you would need to rework the definition yourself.

The second karamba setup does not take into account the different height of each beam but rather takes the average height.

Matthew

Attachments:

mesh from points.JPG, 40 KB
curve beams.JPG, 26 KB

Permalink Reply by Hendrik on September 27, 2016 at 7:44am

Yes, this could be. I have to update my GH. Do I have to download the newest version and overwrite? My Plug Ins (Karamba, Anemone etc.) wont be deleted or something?