In article . com,
Lou wrote:

Well Roger, I was really just looking for a couple of simple
answers. Seeing how this is an experimental hobby, I thought
that I would compare the strengths of the plywood that the designer
put on the plans (old design) against some newer materials and idea's.
It may cost me a few bucks but I want to measure strength and breaking
points against each other.
Lou

You should be able to find that information in the materials handbooks.

I would start with a Google search for "Forest Products Laboratory",
which is the central source of information on wood products. They test
materials and publish the results.