EngDM
Structural
- Aug 10, 2021
- 597
Hello! I am in the middle of getting a spreadsheet together to do some simple steel stud calcs, so I can get away from using generalized tables and can just save design notes easier. I am coming across some inconsistencies with how stud-to-track connections are addressed in the NBCC2020.
NBCC2020 offers S136-16 as it's solution for cold-formed steel design. However, when you go into S136-16 it further references AISI S240-15 in section A2 as shown below. We will come back to this later.
First off, S136 and AISI S240 both provide instruction for web crippling (presented as the governing failure mechanism for stud to track connection conditions).
S136 offers section G5, and Table G5-2 as the solution for this condition, as shown in the screenshots below:
To further support using the equation/tables above, the Bailey Metal Products web crippling tables reference section G5 of S136-16.
However, if we look further into what is provided in AISI S240-15, we get section B3.2.5.1, which provides more clear indication on the use cases of the equation provided (as shown in the screenshots below):
Comparing the two solutions, we can see that differend CR, CN, and Ch coefficients are used, and the overall C coefficient is also different. When comparing the S136 to AISI S240 solutions for a 600S162-43 connecting to a 600T125-43, respective factored resistances of 1.62kN and 2.42kN are calculated.
My dilema is that AISI S240 is not directly referenced by NBCC2020, so I am not sure which equation to apply. I have a few supporting arguments as to why AISI S240 should govern, namely that the equations appear to be much more specific for use with curtain walls. Further, S136 does not offer any provisions on stud-to-deflection-track connections but AISI S240 does, so if I am rejecting AISI S240 as a solution for web crippling, then I should also reject the deflection track solution.
All photo's sourced from AISI S100 and all copywrited materials belong to AISI
NBCC2020 offers S136-16 as it's solution for cold-formed steel design. However, when you go into S136-16 it further references AISI S240-15 in section A2 as shown below. We will come back to this later.
First off, S136 and AISI S240 both provide instruction for web crippling (presented as the governing failure mechanism for stud to track connection conditions).
S136 offers section G5, and Table G5-2 as the solution for this condition, as shown in the screenshots below:
To further support using the equation/tables above, the Bailey Metal Products web crippling tables reference section G5 of S136-16.
However, if we look further into what is provided in AISI S240-15, we get section B3.2.5.1, which provides more clear indication on the use cases of the equation provided (as shown in the screenshots below):
Comparing the two solutions, we can see that differend CR, CN, and Ch coefficients are used, and the overall C coefficient is also different. When comparing the S136 to AISI S240 solutions for a 600S162-43 connecting to a 600T125-43, respective factored resistances of 1.62kN and 2.42kN are calculated.
My dilema is that AISI S240 is not directly referenced by NBCC2020, so I am not sure which equation to apply. I have a few supporting arguments as to why AISI S240 should govern, namely that the equations appear to be much more specific for use with curtain walls. Further, S136 does not offer any provisions on stud-to-deflection-track connections but AISI S240 does, so if I am rejecting AISI S240 as a solution for web crippling, then I should also reject the deflection track solution.
All photo's sourced from AISI S100 and all copywrited materials belong to AISI
