Welded beam splice - partial pen weld?
Welded beam splice - partial pen weld?
(OP)
I have a contractor requesting to splice a beam with a partial pen weld at the flanges (as opposed to full pen). If the full capacity of the section is not required is this allowed?






RE: Welded beam splice - partial pen weld?
"CONCLUSIONS
Partial Penetration Splices
A half penetration butt weld connecting two heavy jumbo
steel sections, and tested in pure bending, has been able to
develop and exceed its nominal design capacity. However, it
failed in a very brittle manner partly as a consequence of a
severe stress concentration created by the unwelded part of
the flange, as well as due to a series of concurrent
metallurgical and welding factors inherent to these type of
details when used for heavy steel section splices. Continuous
visual inspection during welding and ultrasonic testing of the
base metal and welds was not sufficient to avoid this
undesirable failure mode.
Where such welds are to be used, care must be taken to
ensure that (1) splices would not be expected to yield under
realistic loading conditions or (2) a brittle failure of the
splice would not impair the stability of the structure."
http://www.eng.buffalo.edu/~bruneau/AISC%20EJ%2019...
I personally would try to avoid the partial penetration flange splices. Ensure that all the combinations and fatigue, stress concentration, size effects etc are well represented in your factored forces -or ASD equivalents- prior to accept the detail.
A normative answer to your question reduces to examination of the ruling code respect welds, normally the weld chapter in AISC 360 and seismic spec ... I have not looked at them at the moment.
RE: Welded beam splice - partial pen weld?
RE: Welded beam splice - partial pen weld?
If designed correctly, a PJP weld can be used for a WF splice.
www.FerrellEngineering.com
RE: Welded beam splice - partial pen weld?
The beam is a 14x120 that only requires about M=175kip-ft (ASD). If I am not missing anything I just check the base metal and the weld based on table J2.5 (13th edition), with tension normal to weld being the controlling condition correct? I am using a 45 degree single bevel with an effective throat of 1/2" (5/8" - 1/8"). Using E70xx this gives me a weld strength of about 160kips for a M = 200 kip-ft, i.e. it works. Anything else I am missing or should be checking? Thanks
RE: Welded beam splice - partial pen weld?
The weld detail is (AWS) BTC-P4. Is this a field weld or shop splice? If field welded the bottom flange weld can be difficult in an overhead position. Welded from the top, consideration needs to be made for the area of the beam web and fillets.
www.FerrellEngineering.com
RE: Welded beam splice - partial pen weld?
So it sounds like I'm not missing anything obvious in the calcs?
RE: Welded beam splice - partial pen weld?
Basically the calc is correct. Is there any shear force? This can be taken in the beam web. A bolted connection in the web may also help with field alignment.
Note that the root opening for the PJP is zero. A tolerance of 1/8 is allowed "as fit-up". This is another reason CJP welds are often used, they allow for increased field tolerances. Just want you to be aware.
www.FerrellEngineering.com
RE: Welded beam splice - partial pen weld?
Thanks for you help connectegr.
RE: Welded beam splice - partial pen weld?
RE: Welded beam splice - partial pen weld?
RE: Welded beam splice - partial pen weld?
Are you painting or galvanizing the steel? I recently consulted on a residential problem with a pool. The $4 million home had a pool built on a cliff side. The concrete patio and pool where supported by steel trusses, which received only primer. After 7 years the trusses deflected 8" as the top chord rusted away. Although the concrete deck was supported by galvanized decking, the salt water pool had no problem reaching the trusses and beams. Thick salt formations showed where the water leaked in and over the steel. Just another consideration.
www.FerrellEngineering.com
RE: Welded beam splice - partial pen weld?
RE: Welded beam splice - partial pen weld?
Just thinking out loud. Thats how the fab shop does it here. Less qualifications required.