geometric properties of sections

Replies to This Discussion

Permalink Reply by RENE on November 6, 2013 at 3:59pm

Hi Leonardo,

I'm assuming you're doing this for planar geometries? Just use the area component in grasshopper, it gives you the value and the centroid. The polygon center component gives you center points as well for polylines and/or planar polygonal shapes. When doing solids and/or closed meshes you can also use the volume component and/or explode the geometry to extract all faces, which you can flatten and get areas for.

simple stuff, hope it helps

Permalink Reply by Leonardo on November 7, 2013 at 12:50am

Dear RENE,

thanks for your help. Unfortunately area component does not work with output cross-section geometry of karamba.

Best,

Leonardo 

Permalink Reply by Karamba3D on November 7, 2013 at 1:15am

Dear Leonardo,

you can plug your custom cross sections into a 'Generate Cross Section Table'-component. The output-plug 'Table' will give you a string which contains all relevant cross section properties in csv-format.

Best,

Clemens

Permalink Reply by Leonardo on November 13, 2013 at 12:16am

Dear Clemens,

how can I create a cable section (not allow)?

Should I use circular hollow profile component with thickness = diameter / 2 ?

If I do this and extract cross section properties results are not correct.

Best,

Leonardo

Permalink Reply by Karamba3D on November 13, 2013 at 12:32am

I just tested the hollow circular cross section component using a diameter of 1.0cm and a wall thickness of 0.5cm. The results where correct.

Which cross section property comes out wrong in your example?

Best,

Clemens

Permalink Reply by Leonardo on November 13, 2013 at 12:44am

Please have a look to attached images. "Cross section" file shows my section, while "geometry properties" shows extracted values. Value of area is not correct.

Where am I wrong?

Thanks.

Best,

Leonardo

Attachments:

• cross section.png, 247 KB
• geometry properties.png, 191 KB

Permalink Reply by Karamba3D on November 13, 2013 at 12:53am

In Karamba 1.0.3 there was a bug which resulted in shifted columns when producing cross section tables. 

In version 1.0.4 I fixed that problem.

Best,

Clemens

Permalink Reply by Leonardo on November 13, 2013 at 1:30am

Many thanks. I just installed new version and sent you my id-machine. Usually I export cross sections and points from Karamba to Excel and then from excel to Sofistik in order to check results. This is quite time-consuming.

Is there a fast way to export from Karamba to Sofistik?

Thanks.

Best, Leonardo

Permalink Reply by Karamba3D on November 13, 2013 at 1:49am

You do not need a new license file for upgrading from Karamba 1.0.3.

I do not use Sofistik. If it can import DSTV-files you could try the ExToDStV-component.

Best, Clemens

Permalink Reply by Leonardo on November 13, 2013 at 2:19am

Clemens,

please find attached two files. I am using karamba version 1.0.4.

"Cross section" file shows my section (diam 4000 mm - thick. 32 mm), while "geometry section" shows extracted values. Value of area is not correct: should be around 0.40 m2

Where am I wrong?

Thanks.

Best,

Leonardo

Attachments:

• cross section.png, 269 KB
• geometry section.png, 188 KB

Permalink Reply by Karamba3D on November 13, 2013 at 12:09pm

Leonardo,

your table still looks like being generated with version 1.0.3 with the bug: the area should be 3989cm2 (is shifted to column 'r'), the moment of inertia 78515083cm2 (is shifted to column 'ez'). When I generate the table headings and columns correspond to each other as they should.

Are you sure you are running version 1.0.4.? You can test that by placing a license-component on the canvas and reading its output.

Best,

Clemens