"P van Rijckevorsel" wrote in
:

todd schreef
Since you're assuming that the round post has the center of the tree
as it's center, I'll assume that the square post is the same.

+ + +
From a practical point of view this assumption is not realistic.
A round post is likely to be 'whole tree'
A square post is likely to be sawn from a bigger trunk.

This means that a round post consists partly of juvenile wood, a
weakening factor. A square post will consist of mature wood.
Ergo: the strength of the material will not be equal in these two
cases. It will be less in a round post
PvR

I'm telling that from a practical point of view, you don't have the first
clue how the post will fail. (For the record, I've already stated that I
don't know what the compression strength, tensile strength, and shear
strength is for various woods, although I'm sure I could google it if I was
so inclined). Your assumption regarding the strength of juvenile only
matters if shear is the primary failure mode. If the primary failure mode
is tension or compression, then it doesn't really matter what's happening
in the center.

todd