Alternate Weld Type for Weld Between Round Toe of Rolled Section & Plate

[Eng_Struct]

Hi Group,

I need to reinforce the bottom chord of an existing OWSJ and I am considering a steel plate welded to the bottom chord. The plate will extend past the toe of the existing angle toe on both sides so that a weld can be made from above. For fillet welds between the round toe of rolled section and the plate, the code allows you to consider only 3/4 of the thickness of the rolled section for weld size (see image below). My challenge is that the resulting fillet weld thickness based on this requirement does not get me the strength I need for the weld.

I guess I can always increase the length of the fillet weld to compensate for the reduction of weld thickness but want to know if there are any other types of welds that can be specified for this particular application.

Thanks!

 

[dik]

Those would both be fillet welds... if on the radius of the HSS, then possibly flare bevel welds... I'm not so generous on the amount of 'space' left at the top of the weld... Sorry... the 1.5mm is approx 1/16", which I use...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[SJBombero]

It would be an overhead weld but the cover plate could be narrower than the width of the existing truss bottom chord.

 

[dhengr]

StrucEng1992:
Those don’t look like overhead welds to me. As long as the cover/reinforcing plate is sufficiently wider than the bot. chord on the stl. jst., they would be downhand welds, the easiest weld to make. The need for both of those details is that it is difficult to determine/verify the throat size (the important design size/dimension) for those fillet welds when: (a) you burn the top square edge off the flg. tip; or (b) you run the fillet weld well up onto a rounded flg. tip. Without member sizes, thicknesses, shear flows, loads, allowable weld stress, etc., it’s tough to comment further. Your max. weld throat would be (.707)(.75t) per inch of weld, and if I could make it work, I would use a slightly smaller continuous fillet. That’s really easier weld to make and a better weld than a stitch weld.

 

[bugbus]

Perhaps some amount of grinding of the edge of the flange would allow you to turn this into a larger groove-type weld?

 

[desertfox]

Hi StrucEng1992

I think the fillet in this case is probably your best option and increasing the weld length as you suggested, unless you want to use the option posted by gusmurr.

I looked at this website for w3ld options

https://www.millerwelds.com/resourc...of-weld-joints-and-tips-for-improving-results

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Eng_Struct]

Thanks all for the comments!

grinding the edge is too much work that the owner may not be willing to go for. I think I will stick with increasing the weld length.