Error optimize cross section??

Hi everyone,

I have a problem with the Optimize cross section component. I have copied and modified the CrossSectionValues.csv file so that it has only HSS square hollow sections and I imported through the Read cross section component in Karamba. Then I have selected the initial section through the Cross section selector. When I use the Optimize Cross Section component it appears the following runtime warning:

1. 388 cross sections need to be bigger than their biggest family member.

Could you help me to figure out what is the error?

You can see the gh definition in the image attached.

Many thanks in advance!

Attachments:

optimize cross section definition.PNG, 160 KB

Replies to This Discussion

Permalink Reply by Karamba3D on August 26, 2016 at 12:55pm

Hi Simona,

the cross section optimization algorithm takes the incoming list of cross sections and evaluates the utilization for the first cross section in the list that matches the cross section family of a given element which is selected for optimization. If that cross section is sufficient it is set as the new cross section of the element otherwise the algorithm proceeds to the next item in the cross section list. In case that no sufficient cross section can be found the last matching item in the cross section list is chosen and a warning is issued. Check whether your largest cross section is too weak.
Best,

Clemens

Permalink Reply by Simona on August 27, 2016 at 2:42am

Ok thank you very much for your reply!

I'm sorry to bother you again, but actually I would still have the problem with the local axes of the elements that I could not solve. Unfortunately the local axes of the elements are not directed in the same way and therefore I can not assign the wind load with the Mesh load component (the wind load is directed along the local y-axes, but sometimes the local y-axes is directed along -y and sometimes along y). Is it possible to redirect the local axes of the elements in such a way that these have the same local axes?
You can see in the attached image how the local axes of the elements are directed.

Attachments:

local axes.PNG, 166 KB

Permalink Reply by Karamba3D on August 31, 2016 at 7:20am

Hi Simona,

you can use the 'Orientate Beam'-component for that. See the manual for details.

Best,

Clemens

Permalink Reply by Simona on August 31, 2016 at 9:56am

Ok Thank you very much! I will try to use the component that you told me!

Permalink Reply by Simona on September 5, 2016 at 8:26am

Dear Clemens,
I'm really sorry to bother you again. I tried using the component that you told me, but I still can not solve the problem. Orientate beam component allows me to change the local x and z axes instead I should reorient the local y axis. Could you help me? Or recommend me some tutorials, website that explains how to do? I am also interested in Karamba workshops that teach how to use karamba in Italy since I have several difficulties with the program.

Thanks in advance!

Permalink Reply by Karamba3D on September 6, 2016 at 1:45pm

Dear Simona,
you could plug your new Y-axis into the 'Z-ori' input-plug and set 'Alpha' to 90°. Another way to solve the problem is to use the cross product of the x- and y-direction in order to get the z-vector.

Best,

Clemens

Permalink Reply by Simona on September 8, 2016 at 2:48am

Dear Clemens,

I think it works as you say, but my new local y axes are the normal vectors at the mesh edges at the midpoints, and since some edges are shared, I have double normal and double beams. If I use Remove Duplicate Lines it doesn't work. How can I do? You can see in the image attached the gh definition to find the normal vectors.

Many thanks in advance!

Attachments:

orientate beam.PNG, 84 KB

Permalink Reply by Karamba3D on September 8, 2016 at 11:13am

Dear Simona,

this is rather a general Grasshopper question. Sorry, I am not an expert on that.

Best,

Clemens

Permalink Reply by Simona on September 10, 2016 at 4:12am

Dear Clemens,

I managed to solve the above problem. Using the Orientate beam component and doing as you told me, the local y-axis are directed as I want. But looking at the wind load, I think there is another mistake. Which could be? You can see in the image attached the new local axes of the elements, the wind load e the gh definitions.

Thanks in advance!

Attachments:

Permalink Reply by Karamba3D on September 12, 2016 at 1:18pm

Dear Simona,

Check the normals of the mesh which you use as input of the MeshLoad-component. Try to use a smaller definition for testing.

Best,

Clemens

Permalink Reply by Simona on September 13, 2016 at 8:01am

Dear Clemens,

sorry to bother you again, but I can't figure out what is wrong. I imported my geometry in rhino, so you can see attached my karamba definition. Could you help me to figure out what is wrong, please?

Many many thanks in advance!

Permalink Reply by Karamba3D on September 18, 2016 at 11:28pm

Dear Simona,

you specify the windload to act perpendicular to all four sides of your volume. The generation of windloads is however limited to one side only by providing input to 'Pos' at the 'MeshLoad'-component. This is why loads result which act in opposite directions.

Best,

Clemens