Materials: Source for Mechanical properties of Wood

[ShamanTcler]

Is there an existing issue for this?

• I have searched the existing issues

Problem description

Finding "validated" material properties can be hard. This link: https://www.fs.usda.gov/research/treesearch/62244 , from the US Dept of Agriculture, Forest Service seems to have sufficient credibility.

The information is available as a PDF: https://www.fpl.fs.usda.gov/documnts/fplgtr/fplgtr282/chapter_05_fpl_gtr282.pdf

With some help, I am willing to assist with the material creation.

Full version info

I am currently building the dev version on windows

Subproject(s) affected?

None

Anything else?

chapter_05_fpl_gtr282.zip

Code of Conduct

• I agree to follow this project's Code of Conduct

[FEA-eng]

I'll just add that wood has orthotropic mechanical properties and in most cases should be modeled with such an approach. Unfortunately, orthotopic materials are not yet supported in FreeCAD FEM but the new Material system laid the foundations for further development in this regard. So it might be better to implement orthotopic linear elasticity first and then add more wood materials to the library.

[pierreporte]

@davesrocketshop what do you think about this?

[ShamanTcler]

I am assuming that material props are going to be useful everywhere. i.e. given density, what does this assembly weigh?

I certainly could see locking out wood as a material for FEM. Though I was quite surprised to see the detail of the mech properties supplied by the forest service....

I will also add I was pleasantly surprised by FreeCad's FEM capability. I took a class at a Junior College in Machining (ran 3 & 5 Axis Haas machines). As part of my "project" I did a FEA model of my part and included it in the presentation. The instructor was very pleased chuckle.

Yes retired Mech Es (wrote software for other engineers to use) still take classes and learn ;)

[davesrocketshop]

@davesrocketshop what do you think about this?

Wood is a notoriously horrible product from a mechanical point of view. There is so much variability that published results will rarely match your wood, and it can change based on humidity and so many other variables. That being said, these do look like reasonable defaults.

Double check the license. US gov sources are generally good, but we don't want to include restricted data.

[ShamanTcler]

I emailed sm.fs.rdpublicweb@usda.gov ..... owners of the website. They will hopefully respond.

[ShamanTcler]

Got a response from Witne Neil today.

Can I assume this is sufficient?

[davesrocketshop]

Got a response from Witne Neil today.

Can I assume this is sufficient?

Absolutely. Just cite him as requested.