10. Why is there a difference in results between the Normal Sustain load (ex. Gr+MaxP (1)) and the Hydrotest Sustain load (ex. Gr+MaxP (2)) in AutoPIPE?

	Applies To
	Product(s):	AutoPIPE
	Version(s):	2004, XM, V8i, CONNECT;
	Area:	Results
	Original Author:	Bentley Technical Support Group
	Date Logged & Current Version	Dec. 2015 10.00.00.10

Problem:

Why is there a difference in results between the Normal Sustain load (ex. Gr+MaxP (1)) and the Hydrotest Sustain load (ex. Gr+MaxP (2)) in AutoPIPE?

Another words, when I review the results, see that Gr+MaxP (1) and Gr+MaxP (2) are significantly different:

Why?

Solution:

In order to answer what is the driving reason behind the difference, break out each load case that makes up these combinations into individual load case combinations

1. First review the Analysis Summary to understand the Combinations:

Notice that the only difference between these 2 combinations is Gr(1) and Gr(2).

2. Create new Code combinations Gr1 and Gr2

3. Run analysis and review results for GR(1) and Gr(2) only:

4. Clearly the results are different between these 2 load cases. Question is Why?

Next review the Static Analysis Set settings under Load> Static Analysis Sets.. command

5. The Analysis Sets Settings Appear to be exactly the same.

Next Review the Hydrotest settings and Pipe Property settings.

6. See the Hydrotest Settings:

7. See the Pipe Property Settings:

The problem has been solved. What you missed the answer. Please see the Hydrotest and Pipe Property dialogs above and ask what would cause a difference in Gravity load?

Answer:

Elementary, the Specific gravity of contents. In the Hydrotest it was set to 1.00 while in the pipe properties it is set to 0.00. Hence the reason for the different values in Gravity.

Set both values to be the same, re-run the analysis, and review the results:

Note: check to be sure that "Include insulation and cladding" has been enabled/ disabled to correctly account for weight during comparison.

A new enhancement has been logged 568905 - Update hydrotest code combination reporting for non-hydrotest load combinations to avoid these issues.

10. Why is there a difference in results between the Normal Sustain load (ex. Gr+MaxP (1)) and the Hydrotest Sustain load (ex. Gr+MaxP (2)) in AutoPIPE?

Problem:

Solution:

Answer:

See Also