Hollow Metal disc loading - the needed thickness of the disc?

ambroa

Hi,
how to calculate the limit of load you can place on the top of the circular plate with a quite big circular hole in it (OD 10 cm, ID 5 cm)? the question is how to calculate the thickness needed to bear 1 kg which is spread on the whole area (1 kg heavy object with the same shape as the plate, a hollow cylinder 10 cm x 5 cm x some height). The plate is in the air, supported by 3 bars on the ring of the plate.
thank you for any help/advice! This is not a homework, I don't want to "get the solution" but be able to compute it for material I'd use than.

picture
http://s3.amazonaws.com/answer-board...bbef84bf5.jpeg

edgepflow

Roark's Formulas for Stress and Strain Chapter 11 has this.