4-sided HSS column connection
4-sided HSS column connection
(OP)
Hi all,
I have question about connection like showed in attachment. I used to work with EC codes so for AISC I need support :) I have two HSS cantilevers attached to HSS 6x6x5/8 column and two HSS beams which are extension for cantilevers to create kind of overhanged beams. On cantilevers there is bending momement 410 kip-in and shear force ~8.5 kip. My first question is can I use in this case 1+0.5sinθ factor for designing welds to column? Because by Chapter K in AISC it is prohibited but I would like to know Your opinion. Second question is do You think differences in outriggers depths will be problematic to transfer bending moments from cantilever to second side? I've checked plastification of HSS wall via chapter K3.2 but I am wondering what can happend on side walls if there are also welded outriggers to post. Thanks for answer.
I have question about connection like showed in attachment. I used to work with EC codes so for AISC I need support :) I have two HSS cantilevers attached to HSS 6x6x5/8 column and two HSS beams which are extension for cantilevers to create kind of overhanged beams. On cantilevers there is bending momement 410 kip-in and shear force ~8.5 kip. My first question is can I use in this case 1+0.5sinθ factor for designing welds to column? Because by Chapter K in AISC it is prohibited but I would like to know Your opinion. Second question is do You think differences in outriggers depths will be problematic to transfer bending moments from cantilever to second side? I've checked plastification of HSS wall via chapter K3.2 but I am wondering what can happend on side walls if there are also welded outriggers to post. Thanks for answer.






RE: 4-sided HSS column connection
Dik
RE: 4-sided HSS column connection
RE: 4-sided HSS column connection
RE: 4-sided HSS column connection
For your first question, I think it's reasonable to prohibit the use of 1+0.5sinθ factor on column face weld, since the faces of HSS won't be stiff enough to provide a uniform stress distribution along the weld length. However, I tried to find this in Chapter K of AISC, both in 2010 and 2016 version, and just can't find it... Could you please provide me the page or anything about this?
Thanks
RE: 4-sided HSS column connection
Your moment is not very high ~50% stressed I do not see an issue with the HSS transferring the load between the offsets.
RE: 4-sided HSS column connection
Dik
RE: 4-sided HSS column connection
I thought about this what is described in definition of Fnw like sandman21 said.
@dik
I've checked this plastification and the ratio is something about 40% so you are right it is stiff :) However welds will be the biggest issue. I used to design welds with directional method (von Mises) and with 12" depth outrigger they are too weak, maybe I will use higher outrigger or try "Black Book" tabular method.
RE: 4-sided HSS column connection
RE: 4-sided HSS column connection
You welded angles (Am I right?) to beam on workshop and then to column on site or everything on site?
RE: 4-sided HSS column connection
And yeah...HSS6x6x5/8 is pretty thick, but comparing to the in-plain stiffness of the beam top flange, it will be nothing. Then the top flange tension will go to the stiffer part of the HSS column--the two faces that parallel to the beam longitudinal direction, which probably will result in higher stresses at two ends of the fillet weld? But it's definitely better than the longitudinally loaded fillet weld = =... So I guess some kind of directionality increase but smaller than 1+0.5sinθ^2 will be reasonable.
RE: 4-sided HSS column connection
RE: 4-sided HSS column connection
RE: 4-sided HSS column connection
Do You suggest to reinforce somehow corners of column? About what cleaner options You are talking?
RE: 4-sided HSS column connection
RE: 4-sided HSS column connection
Not at all an answer to your question, but you might find interesting this software:
https://www.ideastatica.com/steel/ (there is option to calculate either accord to EC or AISC)
For me it would take ~10min to model and run check on connection like this
For the first time user of course it would take more , but still you would find this very easy to use.
Best Regards
RE: 4-sided HSS column connection