Design and simulate FEA on Balsa Wood

[Anonymous]

I’ve tried to post to forums about this didn’t get a proper answer. 

Are there any plans to add wood (specifically Balsa wood) as a material to run FEA simulation on ? 

Solidworks can do it even though its a non-linear material.

Please consider adding wood FEA simulation on Fusion 360.

[mickey.wakefield · Accepted solution]

Hi Lanejain008 -

I wouldn't expect so any time soon. Here's why; the assumption you made about balsa wood is not entirely correct. The material itself is not particularly non-linear (not in the way plastic is, for example) but it is highly anisotropic....that is a fancy way of saying that the young's modulus of elasticity is not the same in every direction the material can be stressed in. (This is easy to understand. The structure of the wood inself makes it much stiffer and stronger axially to the grain than against it.) To solve using materials like this, you'll need to be able to account for the different material properties in different directions- and we don't. Adding that functionality would be great, but its also pretty tough, and I don't see it on our plans any time soon. 

As for SolidWorks - they include balsawood as a material, but the material constants associated with it are ISOTROPIC....meaning, they are the same in all directions. When I last used SWX, it did not offer a method for anisotropic material calculation. You can calculate with isotropic materials, if you like, and it is a kind of simplification that you can do, even in Fusion. Just add a material with the properties of balsawood....as to which values to use - this is where this all gets tricky. If you use the values for the grain direction - your balsa will be much too stiff and strong in the transverse direction. If you use the transverse values, it will be much too weak in the axial direction! Either way - you lose! 😞 In general, an engineer like me would tell you to use the weaker value, because this will mean your REAL part will be much stronger than calculated. But in truth - the material is so anisotropic that I am not sure I could recommend analysing the wood without accounting for it.

BTW - both SWX and Fusion 360 (and all other sim softwares I have worked with) have lots of materials included in the standards which, like this example, are not entirely "correct". You really must understand the method of calculation being used and the materials you are defining to use such software properly. You can, for example, also describe an I-Beam as being made out of water in both systems I believe....and I believe you can even get a stress result from both.....but this is, of course, absurd.

[Anonymous]

Thanks for the reply. Really helped.