Ironwood Design Values 1

[craigory28]

Does anyone know where you can find design stresses for "ironwood?" We have a job where the owner wants to use it.

 

[austim]

I suggest that you go back to your client and ask him/her to be specific. ie what is the botanical name of the timber he/she wants?

If you search in Google for 'ironwood timber' you will find that quite a number of rainforest timbers (from Australia, Asia, Africa) share the common name of ironwood (one from Africa is also known as 'Yellow Jarra, which would offend most true blue Australians).

In a couple of minutes searching Google I found three entirely different species all with the same common name; there may well be a dozen more. Unless you have a botanic species name then you won't know what you are being asked to use, and the timber merchants could well be similarly handicapped.

A common use for 'ironwood' seems to be railway ties/sleepers or other similar heavy uses.

The Australian Timer Structures code does have a blanket category for 'rainforest species'. It specifies the top Structural Grade timber as 'F7' if unseasoned, 'F11' if seasoned.

The basic working stresses (ie for ASD) for F7 are 6.9MPa in bending, 4.1 Tension Parallel to the grain, 0.70 maximum shear in beams, 5.2 compression parallel to the grain, 7900 MPa short duration modulus of elasticity, 530 short duration modulus of rigidity. (I leave the conversion to psi to you, if you need it). The stresses for F11 are approx 11/7 times the above.

Just a thought - are you working in an area where the use of rainforest timbers is frowned upon for environmental reasons?

 

craigory28: Have you also tried "USDA Wood Handbook" at

http://euler9.tripod.com?

It contains strength properties for a long list of species worldwide in Chapter 4. It might also define generic terms or colloquialisms like "ironwood" in other chapters, though I don't know if it does nor which chapter. Good luck.