Am designing a pressure connection, to the following nominal dimensions
outside dia = 30mm
inside dia = 20.7 (wall thickness 4.65mm)
internal test pressure = 172N/mm^2
working pressure = 120N/mm^2
As it is a thick walled cylinder, using Lames equation I get the following stresses:
Stress in axial direction = 76.4 N/mm^2
Stress in circumfrential direction = 324.4 N/mm^2
Stress in radial direction = -171.6 N/mm^2 (@r=internal radius)
I need to find out what material to specify (thinking of using St. St. 1.4005 [416 s21] approx proof stress = 280 N/mm^2).
There are no other variables involeved (e.g. temperature/vibration/cyclic loading conditions).
I think I should be using Mohrs circle or Tresca criterion, but have never used these before, and only seen examples for thin-walled theory.
Can anyone please point me in the right direction