Shear Studs Welding enquire 1

[tristan861]

Hello Guys…
I’m using shear studs for an embedded plates (Steel to pre cast concrete connections) but it happens that the beams have high moments end forces. So I have to use large diameter shear studs (up to 1’’ or more).

The problem here is they told me that the welding gun available in the shop can weld up to ¾’’ only. So for larger stud diameters they will use normal welding (maybe fillet I’m not sure).

So my question is: Is it ok to use other kinds of welding the diameter of studs other than the Nelson gun? Or is it like the gun guarantees full bonding between the plate and the studs?

And in case if it is not OK. What is my alternative option? I checked the capacity of the regular anchor rods in tension and its way less than the shear studs capacity. So it is not an option in my opinion.

Your help would be so much appreciated.

 

[tristan861]

I'm not using this detail anymore but out of curiosity:

The thickness used in this was 1.18'' and was checked due to flexural yielding due to tension and bearing in the minor axis. Is that not enough to consider the plate '' rigid enough''?

 

[Huevo]

strength ≠ rigidity

The great Hardy Cross said "strength is essential but otherwise unimportant".

 

[sandman21]

The assumption Hilti makes is that the plate is sufficiently stiff to transfer tension forces without the plate deforming. A 1.18" thick plate will not be sufficient to accomplish that goal. A flexible plate will not have the force transfer desired, resulting in load being concentrated in the top anchors.

 

[KootK]

Is that not enough to consider the plate '' rigid enough''?

I would consider it rigid enough. For strong axis bending in the cross section, the web of the supported member itself stiffens the connection plate and makes it rather rigid. It's not as though it's a concentrated moment located at the middle of an isolated, bendy plate.

Either the connection works or it doesn't. I see no reason that the numbers cannot be our definitive guide on that. Plenty of things have been moment connected to concrete via stud groups. I'll usually switch to DBA's on the tension side but that's mostly just a personal preference. And no, based on the information available, I do not expect that the connection would work to develop anything close to the plastic moment of the cross section. A designer is never born with intuition however. It has to be developed through trial and error. Or passed on from those with more experience.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.