Import Dome DXF to ROBOT

[Anonymous]

I am trying to model a dome in Robot. I have a drawing in AutoCAD, where the lines between each node are broken into segments to create the arc from shorter straight bars. The geometry is drawn perfectly and I would like each line to convert to a bar.

However, when I open the drawing in Robot (as either a DXF or DWG) I get the same results; which is a complete dome, broken and with lots of the smaller bars missing and additional ones at the bottom segment, completing the dome.

All the lines in CAD have the same properties so I can't see why this is happening! I've attached the DXF and the ROBOT file when it is just opened from the DXF.

Can anyone help? Thanks.

[Rafal.Gaweda]

Replace arcs by lines in ACAD or draw missing elements in Robot.

[Anonymous]

Thanks!

[Anonymous]

I've meshed the dome and calculated with the self-weight and I am only getting an error reporting Isolated Nodes, which for some reason I can't delete.

I've moved on to try out the wind simulation, which I haven't used before, but the results seem to have been calculated but the load distribution isn't showing on the panels. Instead there is a strange pattern on the panels, and some seem to have been ignored even though they were listed in the elements to be considered. Could you help with this?

[Rafal.Gaweda]

1. File please
2. Panel \ claddings should be "flat" for Wind Simulation
maybe this can help you:
http://forums.autodesk.com/t5/robot-structural-analysis/api-objects-geometry-to-triangles-converter/...

[Anonymous]

Rafal,

The ROBOT file was too large to attach so I've uploaded to Dropbox: https://www.dropbox.com/s/jtx53azl9gd5o4r/12mPembrokeshireMESHFinal2.rtd?dl=0

I used the add-in to flatten the panels, but the results are similar for the Wind Simulation; the creamy yellow appearance and although the loads seem to have been calculated I can't view the results distributed on the panels.

Two of the panels did not convert to flat panels. I tried again separately but no luck

[Rafal.Gaweda]

It would be much easier if you correct model \ each "triangle" to have the same number of divisions (bars) on each edge

Eaxmple for 1 triangle:

macro here:

http://forums.autodesk.com/t5/robot-structural-analysis/api-get-local-axis-of-finite-elements/m-p/59...

[Anonymous]

Orginially the geometry of the dome was such that there were 6 No. bars and edges to each 'triangle'. That's how I imported the geometry and drew the panels originally. All the additional nodes were created due to the meshing and it split the bars in to smaller lengths where the meshing is smaller. It would be ideal if this was avoided, but it's a problem I often face with Robot? If I redraw each panel and re-mesh I'm sure the same will happen again. Is there a way around this?

[Anonymous]

Ah, I see, sorry I didn't watch the video all the way to the end. I'll give this a go. Thanks!

[Anonymous]

I re-meshed as above and converted the FE elements to panels and successfully completed the wind simulation. I am unsure about the wind profile though relative to the height of the structure, can you explain which factors should be applied? I haven't been able to find anything relating to this in the British Standards. The max pressue calculated for a wind speed of 24.5 m/s and altitude of 86m is 0.21 kN/m2 which seems quite low?

[Rafal.Gaweda]

See this:
http://forums.autodesk.com/t5/robot-structural-analysis/terrain-type-wind-simulation/m-p/5238985/hig...