On Sun, 28 Oct 2007 17:34:42 -0700, Lou wrote:

I want to make several samples of materials for covering my plane,
(plywood, composite, ceconite, etc....)
And I would like to find the difference with some kind of scale or
pressure meter to find the breaking points. Has anyone done this?

The problem is, what question are you really asking?
In the labs we made coupons that tested tensile strength and
elongation in different planes such as pull yield, compression and
perpendicular to the surface. If it's shear then you have to define
over what length. If it's a pressure yield, over what area and how is
it distributed.

Many labs have the equipment to do the tests, but the problem is
defining what tests need to be done to display the pertinent results.
IOW, what strength and in what plane/axis, or what information do you
really need?

Roger (K8RI)
Lou