PASS/NOZZLE-FEM 3.5. Program Manual

3.8.7. Conical head

Table 3.10 shows key features of the base element (shell).

ATTENTION: If the conical bottom is selected from the “Conical shell” branch, then the attachment (fitting, beam element) will cut into the conical surface of the bottom. If the conical bottom is selected from the "Bottom" branch, the attachment will cut into the flat part of the bottom.
Table 3.10
Fig. 3.38. Conical head: LCS and fixing conditions
 
Feature Description
Reference points:

A: head (cylindrical part) bottom.

Local shell coordinate system (LCS):

Axis X: transverse axis in head plane;

Axis Y: transverse axis in head plane;

angle θ of nozzle insertion is taken from this axis toward axis X;

Axis Z: normal axis to head plane.

Orientation in WCS:

All axis can be horizontal and vertical according to the shell options:

Additionally, can flip the element relative to its plane to simulate the head of the pressure vessel.

Shell constraints (dof):

Point A.

All calculations by the finite element method (FEM) fix bottom end of head.

If cylindrical part is set then its bottom part is fixed.

Shell loads:

Inner overpressure.

Outer pressure.

Hydrostatic pressure.

Different temperatures for the head and its cylindrical part.

Thermal strains.

Additional segments:

Defining taper by the wall slope angle or the second diameter.

The base element also allows to specify reinforcing parameters.

ATTENTION::

If the conical head is selected from the “Conical shell” branch, then the attachment (nozzle, structure) will inserted into the conical surface of the head.

If the conical head is selected from the "Head" branch, the attachment will inserted into the plane part of the head.

 

 


PASS/NOZZLE-FEM 3.5. Program Manual

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