Closed hwatt1 closed 1 year ago
Dear @hwatt1 , thanks for the bug report! you are right, kzy needs to be the larger of the two numbers. Here is the updated source file: UtilChecker_EC3.zip It will be part of the next service release. -- Clemens P.S: Also thanks regarding the report of the broken link. I have updated it.
Hi Clemens,
Thank you for such a speedy reply. Happy to help.
Cheers, Harry
Describe the bug I think the formula for calculating the kzy factor in the Utilisation of Elements component in Karamba3D version 2.2.0.180-230616 for RHINO 7, and found in the C++ script CroSecStateImp_EC3.cpp (line 447) I downloaded from a 2014 forum post. I've attached the .cpp file that I downloaded from this forum post: https://www.grasshopper3d.com/group/karamba3d/forum/topics/bending-moment-utilization-caculations
The line of code in question (line 447) is "return kzy1 < kzy2 ? kzy1 : kzy2;", where, to my understanding (although I don't know C++) the line will set kzy to kzy1 if kzy1 is smaller than kzy2, otherwise to kzy2 (essentially min(kzy1, kzy2) in excel speak). From EN 1993-1-1, Annex B, Table B.2, however, I think the formula should instead return the greater of the two.
This error looks like it is also replicated in line 422, for Class 3/4 sections.
I have validated my I-section design with Appendix A of the thesis referenced in the Karamba3D online manual (Reference [9] from https://manual.karamba3d.com/appendix/bibliography, being https://trepo.tuni.fi/bitstream/handle/123456789/25580/M%C3%A4enp%C3%A4%C3%A4.pdf?sequence=4&isAllowed=y also attached (side note: the link on the online manual bibliography for this thesis doesn't seem to work for me)).
To Reproduce Steps to reproduce the behavior:
Notes Attachments:
I-section design thesis from online manual bibliography Mäenpää (2018) – Algorithm-aided structural engineering of steel-framed warehouse.pdf
The beam utilisation code, CroSecStateImp_EC3.cpp (uploaded as .txt as I couldn't seem to upload a .cpp file) CroSecStateImp_EC3.txt
The Grasshopper script that I have taken the numbers from in the above To Reproduce section (zipped as I couldn't upload a .gh file) I_section_utilisation_model.zip
Screenshot of the C++ script and EN 1993-1-1 equations mentioned![Screenshot_C++script_EN1993-1-1](https://github.com/karamba3d/K3D_NightlyBuilds/assets/141137114/aa02b183-0d26-4457-aa0e-5b8132969dcc)