ANSYS APDL - Pressure analysis on simple cylinder VS cylinder with irregular feature

[braunboise]

I am trying to do a simple 2D pressure analysis on a cylinder with notches/steps on the OD and ID of the cylinder. Pressure was applied on a portion of the OD and ID but the result of the analysis shows a heavily distorted cylinder which don't look right to me. Note that i constraint the geometry by applying symmetry to the bottom most line of the geometry to the Y axis (code below)

LSEL,S,LINE,,1,,,1
DSYM,SYMM,Y
ALLSEL

I tried to simplify the problem and created a cylinder with straight ID/OD and applied the same boundary condition and pressure but didn't see the distortion as the irregular shaped cylinder. Do i need to apply additional constraint/BC to the irregular shaped cylinder if so, where should the additional constrain be applied and why the different BC from the regular shaped?

 

[karachun]

Nodal displacements in most FEA postprocessors are scaled by some value (like x10...x1000) for better understanding of results by default. You can set scale factor to desired value.
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