From: "Sprague, Harold O." <SpragueHO(--nospam--at)bv.com>
Date: Mon, 7 Feb 2000 09:24:23 -0600
The most effective solution is the increased fillet weld size. Column base
plate to tube steel welds are frequently greater than the wall thickness
because of the relative allowables. It is not unusual. The limitation on
filet weld size in the ASD Sect. J2 is predicated on the ability to inspect
a fillet weld at the edge of a plate (it provides an edge for the fillet
gauge) and does not apply to your case.
It is best to use the E70 rods. They are the most familiar to welders.
Full pen welds can be used by tacking on backer rods, but the preparation
results in a more expensive weld than simply going to a larger fillet weld.
> -----Original Message-----
> From: Kipke, Richard [SMTP:RKipke(--nospam--at)Haden.com]
> Sent: Friday, February 04, 2000 4:18 PM
> To: 'seaint(--nospam--at)seaint.org'
> Subject: Welding Tubes
> I am trying to develop the full strength (actually close to the full
> strength - 25.5 ksi) of a ts14x6x1/4 (Fy=46 ksi) welded onto another
> tubesteel. The support tube steel contains internal stiffeners to address
> the deformation of the top flange.
> My problem is weld size. I would prefer to do this with a simple fillet
> to simplify the calculation:
> 1/4" (tube wall size)x25.5 ksi = 6.375 kip/inch
> 6.3752 kip/inch / 21 ksi (E70 electrode)=.30357"
> .30357/.707 = 7/16"
> and I would prefer some extra so 1/2"
> We have other methods (more intricate) available to make this
> but I would prefer to keep it simple.
> 1. Is this size weld permissible on a 1/4" wall thickness?
> 2. Is using a different electrode an option - our fabricator informed us
> that there is a chemistry problem with using an e80 or other electrode.
> really not familiar with the use of electrodes other than e70. AISC seems
> to simplify it and does not address any issues of chemistry. Does this
> sound correct?
> 3. Another option is a full penetration butt weld (probably difficult to
> back, but possible) for which the AISC allows the full strength of the
> material joined to be used. How is this achieved vs. the fillet weld
> is limited by the electrode?
> I'm using the ASD AISC. The answer may be in the Tube steel connection
> design Manual, but someone swiped it from our office (and I think he's in
> Russia right now)
> Thank in advance,
> Rich Kipke, PE
> > Structural Engineer
> > Haden inc.
> > 1399 Pacific Drive
> > Auburn Hills MI 48326
> > direct:(248)-475-5144 Fax: (248)-475-5227
> > RKipke(--nospam--at)Haden.com