Trying to figure out how to design Jon boat

Well I've been looking at plans from Uncle John and it looks like I'll only need 5-6 pieces of ply so it should cost me $120 at most for 6 pieces of 1/4 inch. I should have enough money for epoxy, and fiberglass joints, and maybe fiberglass the bottom!

 

For the strength, low weight, and low cost, take a look at style 7781 9.0oz/yrd^2 fiberglass.

It is thin and does not need as much resin as some other types.
That reduces weight and cost.

 

Dcockey, Compression/bending. Yours is a legitimate question.

Consider the direction of the force acting on the panel. If the force is perpendicular to the panel, then my simplistic assumption does not apply. If the direction of force is more nearly vertical, as in slamming, the vectors suggest a difference. I hasten to agree that the forces are never purely vertical, they are distributed.........except when running aground.

I should not have mentioned such an argueable technical matter. My bad.

 

Pressure always acts normal on a surface. Shear stress due to viscosity is tangential to a surface. Pressure due to slamming acts normal to the hull surface, but will generally be less the more vertical the surface is.