Applies To
	Product(s):	AutoPIPE
	Version(s):	2004, XM, V8i
	Environment:	N/A
	Area:
	Subarea:
	Original Author:	Bentley Technical Support Group
	Date Logged & Current Version	Oct. 2015 09.06.02.06

Problem:

The expansion stresses are showing as near zero for axial expansion per BS 7159. Even if we ignore temperature, and apply a displacement to the anchor (aligning displacement against temperature or gravity) in both directions that should apply a large axial load to the line (tension and compression), the pipe is not seeing these stresses as it should.

Answer:

See AutoPIPE setting: Tools> Model Options> Result> Include axial force. Review AutoPIPE help for details on this setting. As indicated in the program help, this feature does no affect on the results. Also see the code compliance calculations for this code. Note that the longitudinal calculation does not have a term for Axial forces (like ASME B31.1 and B31.3) except for bending moments per load case. If you review the forces and moments report you may see that the moments due to thermal expansion are very small. Thus when these moments are used in the longitudinal stress equation the results may contribute little to the stress combination. 

See Also

BS7159 Piping Code Calculation Issues

Bentley AutoPIPE

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

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