DrZoidberWoop
Structural
- Oct 17, 2018
- 355
Did you all see the recommendations in the "Designing for the Future" section of this document?
To ensure that future joints are designed conservatively, it is recommended that:
1) The design of shear conx. considers the minimum available body length published in ASME B18.2.6, instead of using reference thread lengths provided in tables.
2) The "transition area" between the threads and body should be considered in the "N" condition.
This is very interesting because the AISC recommendations conflict with RCSC's take on the "transition area," which states it can be discounted for considering thread exclusion. Furthermore, the authors of the article state, under the section titled But are my Designs Safe, "We do not know of any structural failure that can be attributed to this issue."
I find this interesting because I just finished coding a program for the detailers to use, so they order the proper bolt length. For years, we've heard from our erectors that the TC bolt assemblies have been "shanking out" and the bolts have had to be adjusted and re-purchased, at my company's expense. If the stance in Steelwise is adopted, it will result in longer bolts, with additional washers. I contend their recommendations don't have a strong enough historical precedent and I don't expect any change in the specification. We'll see what happens. Either way, it can't be worse than using the 13th Edition of AISC 360. ha.
To ensure that future joints are designed conservatively, it is recommended that:
1) The design of shear conx. considers the minimum available body length published in ASME B18.2.6, instead of using reference thread lengths provided in tables.
2) The "transition area" between the threads and body should be considered in the "N" condition.
This is very interesting because the AISC recommendations conflict with RCSC's take on the "transition area," which states it can be discounted for considering thread exclusion. Furthermore, the authors of the article state, under the section titled But are my Designs Safe, "We do not know of any structural failure that can be attributed to this issue."
I find this interesting because I just finished coding a program for the detailers to use, so they order the proper bolt length. For years, we've heard from our erectors that the TC bolt assemblies have been "shanking out" and the bolts have had to be adjusted and re-purchased, at my company's expense. If the stance in Steelwise is adopted, it will result in longer bolts, with additional washers. I contend their recommendations don't have a strong enough historical precedent and I don't expect any change in the specification. We'll see what happens. Either way, it can't be worse than using the 13th Edition of AISC 360. ha.
