Resistance Welding Strength

[Baffled Engineer]

I wanted to check the connection strength of an existing OWSJ with resistance welded web to chord connection as shown below.

Can anyone provide a reference (preferably Canadian Code) of how to calculate the strength of the connection?

Would the fused area be the only variable here? It seems difficult to measure. Thanks.

 

[canwesteng]

Do you have drawings calling out the truss manufacturer? Maybe someone here can help you with an old truss catalogue for capacities.

 

[Baffled Engineer]

I do have the truss catalogue supplied by an Eng-Tips member. It's from Dominion Bridge Company (of Canada), but the load tables in the catalogue doesn't indicate which is the critical structural element that would require reinforcing if the load tables are exceeded.

 

[jayrod12]

If I'm reinforcing webs on old steel joists I find it substantially easier to just provide enough reinforcing for the entire load going through the member and connect it to the chords at each end for the new load. Trying to troubleshoot old connections like that aren't worth the 5 lbs in steel you might be saving.

 

[Baffled Engineer]

If I'm reinforcing webs on old steel joists I find it substantially easier to just provide enough reinforcing for the entire load going through the member and connect it to the chords at each end for the new load. Trying to troubleshoot old connections like that aren't worth the 5 lbs in steel you might be saving.

Thanks for the response jayrod12. I don't know if you recall but you were the one who provided me the catalogues...much appreciated.

I have the OWSJ modelled in a structural analysis software, and I find the members (chords and webs) are structurally adequate based on the geometric and material properties indicated in the catalogue, and loading that is not uniformly distributed from snow drift effects.

The only thing I can't confirm is the welded connections. Reinforcing every joint in every truss may not be economical and practical due to the existing mechanical systems and fire separation within the truss space (not shown in the picture), albeit a fillet weld on both sides of the web to develop 100% of the connection force may not be so bad...I just thought there is an easy way to determine the connection resistance of fusion welded members knowing that it's widely utilized in the pre-engineered industry.