cold forming of stiffeners

huangyhg

cold forming of stiffeners
when cold forming an 8mm plate, i.e. bending it to effectively form an 90degree angle, the strain on the outer fibres approaches 20%.
pv codes appear to restrict this strain to 3% or 5% but i have a feeling that this is for pressure parts. is there a code or standard in the structural world that covers %strain in structural members rather than pressure parts??
the cold formed member is an internal tank stiffener.