Request for help meshing and and analysing a part {Solved}

About the development of the FEM module/workbench.

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thschrader
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Re: Request for help meshing and and analysing a part

Post by thschrader »

Reverse engineering part 1:
I couldnt find the dimensions of the 760UB244 beam, used 760UB220 for the PB-1 beams instead.
StPauls_beam_layout_main.FCStd
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reverse_eng001.JPG
reverse_eng001.JPG (76.9 KiB) Viewed 22476 times
cad1234
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Re: Request for help meshing and and analysing a part

Post by cad1234 »

Amazing!! Very, very interesting!!
Cathedral Reverse Engineering!
Working with modern tools on such a historic building and bringing it together with FC! GREAT!
....and for me, so much room for learnig...
..burning to see Reverse engineering part 2..if possible..
Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

@ Thomas - not at my machine at the moment but the base of upper section of the scaffold was built directly on top of the tower walls. I may have a photo of the arrangement - I will delve into my archives :) this afternoon.

I am looking forward to opening your FreeCAD file!
thschrader
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Re: Request for help meshing and and analysing a part

Post by thschrader »

It seems the spaceframe is attached with vertikal hangers at the upper beams.
I can count 14 triangle segments from the photos. But this gives too much gap x
between the frame and the wall. Is that right?
StPauls_02102021.FCStd
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working_stage.JPG
working_stage.JPG (81.64 KiB) Viewed 22312 times
Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

thschrader wrote: Sat Oct 02, 2021 9:00 am It seems the spaceframe is attached with vertikal hangers at the upper beams.
I can count 14 triangle segments from the photos. But this gives too much gap x
between the frame and the wall. Is that right?
StPauls_02102021.FCStd
working_stage.JPG
The frame was attached by a tirfor at the end of each beam inside an out. Safe working capacity 3000kg
https://www.specialisedforce.com.au/pro ... rfor-winch
I have attached an end view.
675kg of material and two men on the platform at any one time.
The platform was lowered manually by a man on each tirfor. Slowly but surely!
Also there was 36 tonnes of scaffold on top of the beams plus a live load which I think was 675 kg of material and two men on each of two opposite sides at anyone time (I don’t think it was in each bay as I have indicated but it may have been - I can’t recall)
The top of the scaffold was supported at the top of the walls (probably about 25 tonnes of scaffold)
All in all a lot of load coming down the columns an buttresses of the cathedral structure itself.
I have attached some screen shots (approximations) my recollection of the layout and sections
Attachments
section through platform.jpg
section through platform.jpg (552.58 KiB) Viewed 22281 times
St Pauls Modular Scaffold Configuration.FCStd
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Main Tower Scaffold Plan View.png
Main Tower Scaffold Plan View.png (320.18 KiB) Viewed 22281 times
Main Tower Scaffold Plan View from sides.png
Main Tower Scaffold Plan View from sides.png (14.31 KiB) Viewed 22281 times
Main Tower Scaffold Plan & Section View LH_2021.png
Main Tower Scaffold Plan & Section View LH_2021.png (41.08 KiB) Viewed 22281 times
thschrader
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Re: Request for help meshing and and analysing a part

Post by thschrader »

Laurie Hartley wrote: Sat Oct 02, 2021 11:27 am ...
The frame was attached by a tirfor at the end of each beam inside an out. Safe working capacity 3000kg
https://www.specialisedforce.com.au/pro ... rfor-winch
...
OK, thanks for the info.
Here is a first try with FEM beams. You can merge the wedge-array (solid) and the hangers (lines)
with boolean-fragments. In gmsh, set mesher explicit to 1-D, gmsh extracts the edges of the wedge-array
by itself. No need to extract the lines "by hand" as I did before. Nice.
Loading each node 150 kg, no selfweight of structure. Round beams d=30 mm steel S235.
StPauls_02102021_FEM_frame.FCStd
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frame_fem001.JPG
frame_fem001.JPG (163.66 KiB) Viewed 22251 times
frame_fem002.JPG
frame_fem002.JPG (158.87 KiB) Viewed 22251 times
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johnwang
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Re: Request for help meshing and and analysing a part

Post by johnwang »

Laurie Hartley wrote: Thu Sep 23, 2021 5:42 am
Follow this, I made an inp file to represent this shape. It could be imported by Open directly. Please remove '.txt' in the file name.
Attachments
HiSpaceFrame.inp.txt
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hfc series CAE workbenches for FreeCAD (hfcNastran95, hfcMystran, hfcFrame3DD, hfcSU2 and more)
Laurie Hartley
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Location: Australia

Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

@ Thomas and John - away from my machine today but am looking forward to downloading your files and exploring them. :)
Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

thschrader wrote: Sat Oct 02, 2021 1:09 pm Here is a first try with FEM beams. You can merge the wedge-array (solid) and the hangers (lines)
with boolean-fragments. In gmsh, set mesher explicit to 1-D, gmsh extracts the edges of the wedge-array
by itself. No need to extract the lines "by hand" as I did before. Nice.
Loading each node 150 kg, no selfweight of structure. Round beams d=30 mm steel S235.
Thanks for this Thomas. I opened the file and ran the mesh and was able to look through the results. There is so much to learn from your files. I will be exploring it in more detail tomorrow. There will probably be some questions, :)
I have attached a screenshot showing the arrangement of how the frame was hung from the main beams. “Spreader” beams were used which resulted in all the loads being transmitted very close to the nodes.
You may also be able to see the deflection in this system which is visible to the naked eye.
Attachments
Suspended Platform.png
Suspended Platform.png (880.3 KiB) Viewed 22070 times
Laurie Hartley
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Re: Request for help meshing and and analysing a part

Post by Laurie Hartley »

johnwang wrote: Sun Oct 03, 2021 5:24 am
Laurie Hartley wrote: Thu Sep 23, 2021 5:42 am
Follow this, I made an inp file to represent this shape. It could be imported by Open directly. Please remove '.txt' in the file name.
I opened your file John - very beautiful - thank you! I have to learn more about these “inp” files. I have been working on my parametric model and changed the node geometry slightly. I will upload a file maybe tomorrow with probably a few more questions :)
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