Hello, I am trying to model hoop stress of a cylindrical pressure vessel but my simulation values do not match theoretical values.

Hoop stress in a cylindrical pressure vessel is defined as (P*D)/(2*t) where P is the pressure, D is the diameter, and t is the thickness.

When I use this formula I am receiving a theoretical hoop stress of 13.25 MPa while simulation is giving me 2.8 MPa.

My parameters are P = 1 MPa, D = 53mm , t = 2mm

I am currently defining the stress plot to show normal stress in y direction.

Thank you in advance.

First, from the screen shot, it appears as if your highest stress is 28.34 MPa (2.8e+1) not 2.8.

Second, why does it appear as if you are applying a vacuum to the outside surface instead of a pressure to the inside surface? (Not that it should make any real difference.)