welding plate on existing wf

[edwin17th17]

q= VQ/ I is the computation of stitch weld for bottom plate.. is V the actual max vertical shear?

am confused what if i have a frame no vertical shear
only horizontal force due to wind.. if i need to add plate at the bottom of wide flange.. how would i compute the welding..

i am confused.. can someone explain this to me..

thanks,

 

[dgkhan]

See if wind load can be taken by beam (acting as column) as an axial load. Than go with 3" in 12 " staggered weld. If beam cannot take it and needs cross-sectional area of plates also, than provide continuous weld. In AISC 13th edition, there is a section addressing welding of built up section subject to compression. It allows you to take as built sections as one , if they are welded continuously I guess. Have a look please.

 

[edwin17th17]

so V is actual max vertical shear, for plate welding right?
just want to be clear on that..

 

[dgkhan]

yes

 

[edwin17th17]

what if it's a column that need additional plate?
do i weld the plate all the way or get the max V and stitch weld it?

 

[dgkhan]

check if column needs plate for moment, axial force or shear and design weld accordingly

 

[JAE]

edwin17th17

For an axial column-type member, the added plate is there for two reasons:

1. Adding cross sectional area, A, to minimize the compressive stress in the shape, and

2. Adding cross sectional properties of Ix and Iy to increase the Euler buckling capacity and this increase the column axial capacity.

You are essentially doing both when you add the plate.

Now to be able to count on the increased Euler buckling, you need to connect the plate with enough capacity so that the buckling load can be taken without the welds between the plate and column failing first.

AISC, in the 13th Edition Manual, has section E6 that covers this issue. Good luck!

 

[edwin17th17]

if i add wt on the flange of the web to increase axial.. does the wt need to go all the way to the base plate?

am confused i have a beam connecting to column web..
if i add wt to column flange am i actually increasing the axial capacity of column per that beam connection..

i know in staad i can fool that but in reality the beam is only connected to column web and will not be connected to wt