	Applies To
	Product:	AutoPIPE
	First Affected Version:	09.01.00
	Found in Version:	11.00.00.05
	Fixed and Released in Version:	11.00.00
	Area:	Analysis
	Severity:	Critical
	Backlog Issue Number:	537789

Problem Description

A stress summary containing a single equation 10 transient with a user defined non-reversing* SAM category code combination may give incorrect stress and allowable results. Note that for this issue to occur, the equation 10 transient defined in the stress summary must have only one other thermal or zero moment combination included, in addition to the user defined SAM category combination. For such a stress summary, incorrect stress and allowable values are reported for all stress equations, which can be un-conservative. Notice that such stress summaries only have a single loadset (Thermal + non-reversing SAM combination) available for evaluation of stress equations for fatigue calculations. Fatigue calculations require two or more loadsets for evaluation of stress equations. This defect is limited to ASME NB piping code.

*Non-reversing are those code combinations for which the “Reversing Dynamic” checkbox is unchecked

Steps to Repeat

To illustrate this defect, the following scenario can be considered:

Step 1: Launch a fresh instance of AutoPIPE and open Class1_tutorial example model

Step 2: Perform analysis on the model

Step 3: Navigate to “Code Comb.” tab of Load Combination dialog

Notice that that the category for “User1” combination under “Code Comb.” tab is set to SAM with reversing dynamic checkbox unchecked

Step 4: Close the Load Combinations dialog and launch the Stress summary dialog

Step 5: Select Summary No. 1 and make the following changes to equation index 2 on the stress summary grid:

Combination 1: Zero moment Case
Combination 2: USER1
Combination 3: None

Step 6: Press Apply to save the changes and then press OK on the stress summary dialog

Step 7: Generate the stress summary and fatigue report

Note that zero stress values are reported for all applicable stress equations with invalid allowable stress values. Also notice that under the fatigue report, only a single loadset is available for equation 10.

Evaluation Criteria

The following considerations are provided to assist in your evaluation of the potential impact of this defect on the results:

1. Evaluate whether this defect has affected any existing models by considering the criteria below:

a. Was the model created or updated in program version 9.1.0 or later?
b. Was the Piping code for model set to ASME NB?
c. Was there any user defined non-reversing SAM category code combination in the model?
d. Was there any stress summary defined in the model having only one equation 10 transient with a user defined non-reversing SAM category code combination?

A 'No' to one or more of the above criteria means that this defect does not affect the model’s results. No further consideration for this model is necessary.

Otherwise the following mitigation conditions may apply:

1. Generally, seismic anchor motion loads are reversing dynamic in nature, and the Reversing Dynamic checkbox for such user code combinations should be checked.

Workaround:

None

Solution

Program should perform a consistency check for all stress summaries defined in the model and disable reporting stress summaries which could lead to a single equation 10 loadset for fatigue evaluation.

Additionally, to assist in the screening of the models created in previous program versions for any potential impact by this defect, the program shall automatically examine the model database after opening the model and generate a report (model name + "_D537789.TXT") listing the stress summaries potentially impacted by this defect. The program shall display the following confirmation message:

“Results calculated for a stress summary containing user defined non-reversing SAM category combination may be incorrect due to a previous program defect #537789. Would you like to review the evaluation report?”
The contents of the critical error report shall be similar to the following sample critical error report:

Defect #537789 Evaluation Report --------------------------------- Model Name: TEST1 Model Version: 09.06.02.06 Program Version: 11.00.00.11 Report Filename: TEST1_D537789.TXT --------------------------------- Stress summary evaluation which include user defined non-reversing SAM category combination have been revised in this program version to correct defect #537789. Please refer to the published defect report for more details and instructions. To assist in the screening of this model for any potential impact by this defect, program has examined the stress summary inputs for this model and has found that stress summary inputs for the following stress summaries listed below may be incomplete for correct stress evaluation. Reporting of these stress summaries will be disable until valid inputs are provided in this program version. After saving this model or running any analysis in this version or later commercial release versions, this screening will no longer be performed.Stress summaries potentially impacted by this defect: ----------------------------------------------------- Stress Summary #1

Also See: