Simulation material

[Anonymous]

Hello,

I am trying to do a simulation of static stresses for a truss structure. I am building it from wood and because Fusion 360 cannot do the wood I tried to make it metal and adjust the properties so it agrees with the wood. However, it says it is using invalid material properties. Does anyone know how I can solve this?

Thank you.

[Anonymous]

Wood is not an isotopic material (its orthotropic) so using metal as starting point still won't be accurate. In a truss configuration I don't know if I'd ever expect to get accurate results by approximating the wood as isotropic with the lowest stiffness and strength values across the board.

Regardless, if you can share the material properties you tried to create I may be able to tell you what went wrong.

[Anonymous]

Yes I know it won't do wood because its not Isotropic. Here is the properties file photo attached. I did normal steel with these traits. On the simulation, it has a question mark next to the material and says it cannot recognise it. 

[Anonymous]

You have a yield strength of 0....maybe that's it? The software went be able to calculate the safety factor with a 0 yield.

[Anonymous]

What if I don't know the wood yield strength for what I have? Should I find an Average balsa wood online?

[Anonymous]

I don't know that there is a yield strength for wood so maybe just put it equal to ultimate or just below.

What are you trying to learn from the simulation?

[Anonymous]

I am trying to see the load distribution on the truss members. What do you mean by put it equal to ultimate?

[Anonymous]

Your tensile strength is 14 mpa (tensile is typically the same as ultimate).

Set yield equal to tensile strength (14 mpa)

This is assuming your strength and stiffness ( modulus) is defined correctly.

Otherwise the values wont be accurate at all.

F360 has wood, but I'm not sure how it treats the material. You may try using a stock f360 wood material.

[Anonymous]

Normal wood doesn't work either. If I set the yield strength equal it still doesn't work. Any other options?

[algor_neil · Accepted solution]

E = 3000 MPa

v= 0.38

G = 80000 MPa

G is way off, should be more like 1087 MPa

Bet you've left the value for Steel in.

[Anonymous]

Yes! Thank You I totally missed that. I remember editing it because I have what it should be but probably it didn't save it and reverted back to the steel value. 

It works now.

Thank you everyone for the help.