| Applies To | |||
| Product(s): | AutoPIPE, | ||
| Version(s): | ALL | ||
| Environment: | N/A | ||
| Area: | Modeling | ||
| Original Author: | Bentley Technical Support Group | ||
Problem:
What does the following Tools> Model Options> Edit> "Include Bourdon rotational effect" do when enabled ?
How is Bourdon effect implemented in AutoPIPE software? does it use the Flexibility Factors and Stress Intensification Factors provided by Codes?
Solution:
The Bourdon translation effects are added to the axial growth effects to get the combined (Total) Global Displacement for the pressure load case.
As mentioned in the online help:
This option allows for the rotational effect at a bend due to pressure to be included in the pressure extension analysis cases (P1 to P100). When pressure is admitted to a bend, the bend tends to elongate and straighten. This is known as the "Bourdon" effect. The elongation effect is included in the pressure extension analysis cases (P1 to P100). Pressure extension analysis cases (P1 to P100) include the extension of both bends and straight pipes as well, but the Bourdon Rotational effect only applies to bends.
Note: The inclusion of pressure extension analysis cases (P1 to P100) do not affect the structural stiffness matrix, and hence, has no affect on other static or dynamic analysis cases.
Note: Pressure stiffening of bends, which tends to increase the stiffness of the bend and decrease the flexibility factor and SIF of the bend, can be applied with or without pressure extension analysis cases (P1 to P100). The two effects are completely independent.
Furthermore, when "Include Bourdon rotational effect" check-box is checked ON it changes the stiffness matrix for bend elements.
Feature History
Implementation of Bourdon Effect was added in AutoPIPE 5.1 under the following ID:
Enhancement 102533:Tracker#:550 - Bourdon rotational effect at bends should be considered
One of the references used was ”AXIAL GROWTH DUE TO PRESSURE. MEL REPORT 10-66, EQUATION (3-28)". Otherwiise the approach for rotational effects are quite standard:
See Also
Tools> Model Options> Edit settings