Properies Card for Ponderosa Pine?

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flyingcadet
Posts: 3
Joined: Wed Aug 03, 2022 2:17 am

Properies Card for Ponderosa Pine?

Post by flyingcadet »

I'm trying to estimate the load capacity of my shed wall, I would like to add an i-beam for a chain hoist on a trolley.

My shed is framed with #2 Pine or Ponderosa Pine. I tried to write my own card, but it collapses under its own weight.

Any help would be appreciated.

FreeCAD Details:

Code: Select all

OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.20.29177 (Git)
Build type: Release
Branch: releases/FreeCAD-0-20
Hash: 68e337670e227889217652ddac593c93b5e8dc94
Python 3.8.10, Qt 5.15.2, Coin 4.0.1, Vtk 8.2.0, OCC 7.6.2
Locale: English/United States (en_US)
Installed mods: 
  * Assembly4 0.12.3
  * CurvedShapes 1.0.4
  * Curves 0.5.3
  * DynamicData 2.46.0
  * FEM_FrontISTR 0.1.0

The source of my values: https://www.fpl.fs.fed.us/documnts/fplg ... 3/ch04.pdf
Attachments
The results of my bad file.
The results of my bad file.
wet_noodles.png (40.93 KiB) Viewed 736 times
Wood_Num2Pine_(Ponderosa).FCMat.txt
(770 Bytes) Downloaded 15 times
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NewJoker
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Joined: Sun Oct 11, 2020 7:49 pm

Re: Properies Card for Ponderosa Pine?

Post by NewJoker »

Can you share the .FCStd file or at least values that you obtained from the simulation ? Deformed shape plot is not enough since it can be scaled. Numbers are what actually matters in FEM.
flyingcadet
Posts: 3
Joined: Wed Aug 03, 2022 2:17 am

Re: Properies Card for Ponderosa Pine?

Post by flyingcadet »

Here are the files as requested. I included one with all settings using the "GenericWood" material that comes with FreeCAD and one that's based on the material card in my original post. I had to delete the results to get them under size limits individually.

Appreciatively,

flyingcadet
Attachments
shed_cad_v2_WoodGeneric.FCStd
(698.04 KiB) Downloaded 16 times
shed_cad_v2_BadMaterial.FCStd
(698.2 KiB) Downloaded 15 times
via_GenericWood.png
via_GenericWood.png (58.08 KiB) Viewed 676 times
wet_noodles_v2.png
wet_noodles_v2.png (58.27 KiB) Viewed 676 times
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NewJoker
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Joined: Sun Oct 11, 2020 7:49 pm

Re: Properies Card for Ponderosa Pine?

Post by NewJoker »

The density is wrong - it's defined as 400 kg/cm^3 instead of 400 kg/m^3. This causes the gravitational load and thus also the results to be exactly a million times larger than they should be. You have to be very carefult with units in FEM.
flyingcadet
Posts: 3
Joined: Wed Aug 03, 2022 2:17 am

Re: Properies Card for Ponderosa Pine?

Post by flyingcadet »

haha, that's what I get for setting the properties in the middle of the night.

Thank you for the help!

Appreciatively,

Flyingcadet
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