Shells of Revolution Axisymmetric Loading

With loads symmetric about the vertical axis of rotation, Eqs. (4.4), (4.5), (4.6) and (4.7) simplify considerably 

Stresses are independent of 9, and all partial derivatives with respect to 9 disappear. 

Ni g = Ngi = 0, otherwise they would produce asymmetrical deformation with respect to the vertical axis. 

There is no variation of other stress resultants with 9. 

The component X of the load must vanish it would produce twist about the axis and shear deformation. 

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