Coping the bottom flange of a beam

[bureqq]

I have noticed that for example, secondary beams (floor beams) of platform decks have coped bottom flange like in attachment, detail 5..does anyone have an idea why is that the case, i doubt that it's only for installing purposes?

 

[Duwe6]

If you are talking about Detail #5, it sure looks like dimensional relief so that the opposite end can be connected, and then the tapered end swung into place without having to force the column/girder it is connecting to outwards to clear a square end. Makes life easier for the erection team.

 

[bureqq]

thank you for your response,

both ends are meant to be tapered, so it seems that it is mainly for installation purposes..because there are a lot of those secondary beams and although i saw that cut even on some big primary beams but they had more complicated stiffeners. is it possible that that cut is also performed for some stress release?

 

[Duwe6]

Nope -- there is no significant stress in those regions. Look at the load paths - nothing comes close to the tips of those flanges at the ends.

 

[racookpe1978]

Detl 5 isn't a plan view of the two other detailed views - proportions are wrong, and the 2:1 taped upper flange on the beam would still hit the horizontal girder on the other two views.

But, in the two other views, the lower plate (part nbr 2) has no weld symbol of instructions.

 

[paddingtongreen]

Detail 5 is for the bottom flange of detail 14. It can only be for clearance. Not sure I'd do it that way but it works.

Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin