huangyhg

hss local bending check
i have a situation where a hss6x2x1/4 horizontal outrigger is welded between a hss12x2x1/4 stair stringer and a hss6x6x3/8 building column. the hss6x2x1/4 is welded all around at each end. i am very concerned about the connection of the hss6x2x1/4 to the building column becuase of local distortion that could take place. what would be the correct way to analyze such a situation. i have looked thru the hss connections manual, but does not address this situation exactly. the reaction from the stringer to the hss6x2 is 6 kips and the hss6x2 is approximately 9 in; therefore, you would have a 54 k-in moment at the face of the building column.
thank you,
val
yield line theory is only way that i know of how to analyze this situation. there is an example of this in "design of welded structures" by blodgett, page 3.6-7 thru 3.6-9.
if a 6x6 outrigger is used, would this prevent the distortion by taking the moment directly into the sidewalls of the column?
yes, the 6x6 would work. the problem is that the fabricator took it upon himself to go ahead and fabricate and install the hss6x2x1/4. what i am trying to say is that everything is installed and now i have to provide damage control.
is the hss6x2x1/4 horizontal or vertical? is the 6 kip load vertical or horizontal? if the load is vertical and the 6" dimension is vertical and the weld is centered on the column then the 3/8" wall is receving a 9kip push and 9 kip pull at the center of a 6" column face. my "back of envelope" calculations says 0.04" deflection in at the push location and 0.04" deflection out at the top location for a maximum rotation of almost one degree and yielding of the column face ,(ng). weld angles, (2x2x1/4 by 10" long), stiffeners on both long sides of the hss6"x2"x1/4" to bring the force out to the walls of column.
how did you check the yielding of the column face? i looked at the blodgett formula as discussed above and got an allowable force of 10.5 kips. i could be missing something though. the force is vertical. the hss6x2 is llv.
weld a 6" wide horizontal plate to the top and bottom of the beam to transfer the flange forces out to the column walls.
then just check the resultant bearing stresses on the walls with the standard code formulii.
courtnvm,
accodring to "hollow structural section- connections and trusses" by: j.a. packer and j.e. henderson,
this connection can resist up to 190 kip.in before the failure occurs by yieldig the face of the hss column.
prof packer is 'the man' when it comes to hss connections.

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