Can you reduce the threat of peel by designing your adhesive joints as a 3-layer sandwich instead of a 2-layer lap joint? That way, your bonds would be constrained to shear loads, similar to the way a clevis pin is loaded when placed through a forked clevis.In support of points brought up by Orion...
Peel is the achilles heel of adhesives, so just don't go there. You do this by good joint design.
Achieving maximum strength shouldn't be the goal. I'm sold on the toughened adhesives over the high strength ones. Reliability is the goal. High strength can be achieved by maximizing bond surface area.
Peel is all about Substrate Deformation. When the substrate deforms under tensile load, it stretches the adhesive beyond its elastic limit and causes delamination at the bondline itself. That is the stress riser of adhesives. Design your joints so that you don't have stress risers, just as we do in aluminum fabrication; we know the weakness, so we must design accordingly. That's why I think it's improtant that I go with the PVC foam ribs rather than the traditional formed aluminum ribs...I'm getting away from the stress risers.