I have a metal piece that I would like to replace with plastic (long story). The original piece is 34 mil thick non-magnetic stainless sheet, bent in an L shape with about a 3/4" radius. It's not structural, but I would like the plastic version to be as rigid as the original. I'm not sure what sort of SS it might be, and 34 mils is an odd thickness. I don't know if it's 1/32" & a bit thick, or 20 gauge & a little thin.
I know that the bend would have work hardened the metal a bit, and I would think it's a bit stiffer as a result. The part that always baffles me is that the bending formulas are all in terms of the Modulus of Elasticity, which doesn't vary much. I expect work hardening & the like to make a difference, but the formulas say not. I'm basically trying to figure out how thick a piece of plastic would be required to match (or slightly exceed) the original stiffness. I have the modulus of elasticity for the plastic, but no real idea of what the steel might be.
Is it likely to be 304 SS or something similar? I found properties on-line, and the modulus of elasticity for 304 is around 200 GPa. It doesn't vary signficantly for nay of the 300 series steels. The plastic is only 2.5 GPa. If the stiffness varies as the thickness cubed, that says I need the plastic to be roughly 4.3 times as thick, or about
0.15". This is do-able, although 1/8" thick is probably easier to get.Does this make sense, or am I missing something?
Thanks!
Doug White