modelling the grillage of glass dome

[Jummybear]

Hi,

I need to calculate approximate steel volume of glass dome for our budget department. Can you give me some guidelines how to model steel grillage elements in robot? I have found some videos and posts in this forum related to my topic, but construction in video was regular with midpoint at a top. Our structure supposed to be with triangle moduls with a side length od 1,5m. The dimension of dome is: D1=26m, D2=22,5m, H=3,5m. As i said before, i dont need the precise calculation, so if its a problem to model such structure quickly (with different D1 and D2), we can make a simplification and take only one diameter of 24m for example. The shape of grillage is somethink like in this video: https://www.youtube.com/watch?v=Z2UsMaz5CRA

I will be very appriciated for any advices.

[Rafacascudo]

What I usually do is to Model the grillage in a plane(XY) , copy the nodes coordinates from the nodes table , paste them in excel and them apply a formula (function of X,Y coordinates)to change the  nodes Z coordinate according to the Dome´s shape (spheric,parabola,etc) . Then, paste the transformed Z coordinate back into robot nodes table.

[Rafacascudo]

Something like this

http://screencast.com/t/oWcDQEL0DoBP

[Jummybear]

Do you use any API for this work? Or you do it manually?

UPD posted and then saw you video. OK, I understand. But in my case I have dome with 2 different diameters and triangle shape of grillage. Its not so simple 🙂 I will attach a picture.

[Rafacascudo · Accepted solution]

No API

The problem is the same . You just need to find which equation gives the Z coordinate in function of X ,Y.

Maybe you can draw it in autocad and import the dwg or dxf into Robot

[StefanoPasquini6790]

Hi,

The really best way to have a performance and editable model is to use dynamo for robot plug in. Or you can use grasshopper for rhino, save the model in dxf and open it in robot.

However, see in youtube the power of dynamo for robot and you will go crazy!!!

Greetings

[StefanoPasquini6790]

More info here:Autodesk Labs: Dynamo Plug-in for Robot Structura…: http://youtu.be/yZrAGo089B0

[Jummybear]

Rafacascudo

Thank you for advice. I didnt get the oval-shape dome in 3D, but got the round one through autocad-robot-excel-robot. Its not the quickest and easiest way but at least i get something to go further.

StefanoPasquini6790

Wow, looking the vidoe I can say that it looks like awasome plugin! I must definitly try it. As I understand its a free of charge plugin, anyone can download and use it. Can you provide more info about this plugin, any kind of help or toturials how to use it? Interface looks simple but that arrows and windows... Anyway I try it, thank you for attention to such amazing plug in!

PS I get my dome in 3D in Robot now, now I should define the loads. Any ideas to do it better and faster way? I invented 2 ways: 1. Define bar load to all bars (~780pcs) 2. Define claddings manually and define exact load to each cladding (~250...300pcs). First way is quicker, second one is very time-consuming (I cant define one big cladding to 3D structure so I need to define each triangle-shaped cladding separately) but more accurate. Maybe there is something I missed?

Thank you guys for help!

[Rafal.Gaweda]

http://forums.autodesk.com/t5/robot-structural-analysis/dynamo-plug-in-for-robot-structural-analysis...

[ZhouFang914]

Hi, I am new to Robot. May I ask that did you use Frame 3D or Shell to build your model?