When modeling flexible nozzles, adhere to the following requirements:
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Frame only one pipe element into the nozzle node.
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Do not place restraints at the nozzle node.
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Do not place anchors at the nozzle node.
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Do not specify displacements for the nozzle node. Refer to the displacements at flexible nozzles below.
CAESAR II automatically performs the following functions:
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Calculates nozzle flexibilities for user-defined nozzle/vessel data.
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Calculates and inserts restraints to simulate nozzle flexibilities.
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Calculates flexibilities for the axial translations, circumferential, and longitudinal bending.
You must complete the error check process to view these calculated values.
CAESAR II uses the following criteria for its calculations:
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Shear and torsional stiffnesses are assumed rigid.
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Nozzle configurations outside of the WRC 297 curve limits are considered rigid. It is not unusual for one stiffness value to be rigid because of curve limits and for the others to be suitably flexible.
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You can use Vessel Temperature and Material in the WRC 297 auxiliary data area to optionally compute a reduced modulus of elasticity for the local stiffness calculations.
Example
Schematic
WRC 297 Input
WRC 297 Output
WRC 297 Nozzle Calculations