Thick walled Pressure vessel -Principle stresses

[har_rai]

Homework Statement

Hi, I trying to calculate principle stresses for pressure vessel (thick walled) which is pressurized from inside. I calculated all 3 stresses radial, hoop and axial and looking for what formulae to use to get to principle stresses.
thanks

Homework Equations

The Attempt at a Solution

 

[Baluncore]

Can we assume your thick walled pressure vessel is a cylinder?
The stresses must be added. But they are perpendicular and so are independent.

The radial stress is compressive, the other two tension. Hoop stress is usually twice the axial and so hoop stress is probably the limiting factor in a cylindrical vessel.

 

[Chestermiller]

Homework Statement

Hi, I trying to calculate principle stresses for pressure vessel (thick walled) which is pressurized from inside. I calculated all 3 stresses radial, hoop and axial and looking for what formulae to use to get to principle stresses.
thanks

Homework Equations

The Attempt at a Solution

The radial, hoop, and axial stresses are the principal stresses in this system.

 

[har_rai]

The radial, hoop, and axial stresses are the principal stresses in this system.

Thanks for the reply. So there is no shear stress in this, only 3 normal stresses (radial, hoop and axial).

 

[Chestermiller]

Thanks for the reply. So there is no shear stress in this, only 3 normal stresses (radial, hoop and axial).

Correct.