GMcDonald
Structural
- Aug 28, 2009
- 2
This is my first time designing joint cans using ISO so I may be misinterpreting it, but it seems to me that there may be an issue with the joint minimum strength requirements.
ISO 14.2.3 states:
All joints, except those identified as being non-critical, shall additionally be checked to ensure that joint strength exceeds the brace member strength, using Equation (14.2-2):
?Rj * Sj / Rj <= Ub / ?zj (14.2-2)
where, additionally,
Ub is the utilization of the brace (see Clause 13) at the end adjoining the joint, which may conservatively be taken as the maximum utilization along the brace or even more conservatively as unity;
?zj is an extra partial resistance factor to ensure that members fail before the joint yields.
In the section where Ub is defined, the utilization of the brace may conservatively be taken as the maximum utilization along the brace or more conservatively as unity. However, if the maximum utilization of the brace is less than unity, then by setting the utiliztion equal to one would increase the right-hand side of the equation which would reduce the required resistance of the joint, Rj, on the left-hand side of the equation. This change would then be unconservative.
If anyone has any insight to this issue, I would greatly appreciate it and if this is indeed an error in ISO, does anyone know how to go about contacting the appropriate channels of communication?
ISO 14.2.3 states:
All joints, except those identified as being non-critical, shall additionally be checked to ensure that joint strength exceeds the brace member strength, using Equation (14.2-2):
?Rj * Sj / Rj <= Ub / ?zj (14.2-2)
where, additionally,
Ub is the utilization of the brace (see Clause 13) at the end adjoining the joint, which may conservatively be taken as the maximum utilization along the brace or even more conservatively as unity;
?zj is an extra partial resistance factor to ensure that members fail before the joint yields.
In the section where Ub is defined, the utilization of the brace may conservatively be taken as the maximum utilization along the brace or more conservatively as unity. However, if the maximum utilization of the brace is less than unity, then by setting the utiliztion equal to one would increase the right-hand side of the equation which would reduce the required resistance of the joint, Rj, on the left-hand side of the equation. This change would then be unconservative.
If anyone has any insight to this issue, I would greatly appreciate it and if this is indeed an error in ISO, does anyone know how to go about contacting the appropriate channels of communication?
