All-around welding of HSS Tubes to baseplates

[EngDM]

Hey all,

When modeling an HSS all-around weld to a baseplate in RISA Connection, it appears to be calculating the weld neglecting any of the corners. That is to say, it seems to be only welding the "workable flat" on all sides, and not a true all-around weld. They are taking the workable flat as B-2*(2*t_nom) which is curious, as I've found references where it is B-2*(2.25*t_nom) or even B-2*(3*t_nom).

For instance, when modeling my moment load it is saying I have a 3.94kN/mm force in the weld. Which, if we take my moment of 30.5 and HSS tube of 102x102x6.4, appears to check out:

30.5kN-m/0.1016m/(2(101.6mm-2*6.35mm))=3.94kN/mm

However using the section modulus of the weld method, and taking it as true all-around (neglecting any curvature of the HSS) I get a value of 2.2kN/mm.

I am curious as to if there is any reason why RISA might not be welding to the corner of the tube? The force in the weld is much much higher.

 

[YoungGunner]

I asked this question less than a year ago (link below), and my conclusion is because Risa hasn't gotten that far yet. They've built the easy version of the calc and haven't advanced it yet. I built my own spreadsheet based on the advice to those who responded (thanks to them, really helped me understand the concepts).

https://www.eng-tips.com/viewthread.cfm?qid=500558

 

[EngDM]

https://www.eng-tips.com/viewthread.cfm?qid=500558

Thanks for this.