Certification by Analysis Uncertainty Quantification

Participants,

New files related to the structural aspects of the Challenge Problem have been uploaded to the aiaa-uq4cba.org website.  These comprise two documents, one providing a design description of the radome assembly, the other an example reserve factor/margin of safety calculation using the simple structural model; two csv-files containing the stiffness matrix representing the simple structural model (one in Imperial and the other in SI units); and, finally, updated NASTRAN input files.

Please inform us if there are any issues with the files or of there is missing data to perform the calculations.

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Thomas Wittenberg
Engineer
Boeing Commercial Airplanes
Seattle WA
(425)387-7978
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[件名] Re: Structures Files Uploaded
[ファイル名] 20260223184503.zip
[パスワード] AUi0Vf5D

Here is password for unzipping attachment sent earlier.

[SUBJECT] Re: Structures Files Uploaded
[FILENAME] 20260223184503.zip
[PASSWORD] AUi0Vf5D

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Thanks for pointing out these issues.  A new document has been uploaded with the fixes.

Regarding the 1st issue, the "4" should indeed by a "9" (this was a typo) and has been fixed in the new document.  Note that the summations were done correctly in the numerical stiffness matrix.

Regarding the 2nd issue, the reason why the boxed numbers are not exactly zero is a minute difference in the left and right hand side y-coordinates.  The interface coordinates were copied directly from the Nastran model and there is a slight difference between right and left, which only shows up at the 4th decimal.  The calculations in the new file are based on y-coordinates of precisely +/- 16.1 and shows values of exactly 0 in the stiffness matrix at the boxed locations.

For the 3rd issue, the proper way would be to use the resultant forces in case there are other components (Fx) in addition to the vertical one (Fz).

Hopefully this answers your questions and thanks again for pointing out.  Let me know if you have more questions.

Thomas

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Thomas Wittenberg
Engineer
Boeing Commercial Airplanes
Seattle WA
(425)387-7978
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Original Message:
Sent: 23 Feb, 2026 04:44
From: Masataro Amano
Subject: Structures Files Uploaded

Dear Thomas,

 

I hope this message finds you well. I have a few questions regarding the content of your uploaded files, as detailed in the attached document. Clarifying these points will be beneficial for those involved in the structural aspects.

 

Your insights are valued, and updating the documentation with your responses will help ensure clarity and avoid future confusion. Thank you for your attention to this matter, and I look forward to your prompt response.

 

 

Regards,

 

 

Masataro AMANO