Effective area of partial penetration weld.

[PBEIT]

I have two steel text books and the steel manual that all refer to R_n for the base metal being F_BM*A_BM where A_BM is the "Cross-sectional area of the base metal". Neither of the text books describe what how to calculate A_BM and in the manual Table J2.5 just refers you back to J4 which is where the equation came from with no explanation of what it is. Help please!

 

[SteelPE]

When using pip welds I refer to AWS to figure the effect throat thickness of a given weld. When calling one out on the drawings I indicate the effect throat thickness on the weld callout.

 

[wannabeSE]

Perhaps you can provide an example. If the weld is 4" long at end of a 1/4"x4" bar, the area of the base metal is 1/4"x4"= 1 in²

 

[PBEIT]

Wannabe,

I'm looking for the area of the base metal when welding something like a 45 degree V with a depth of 1/2" X 4" long.

Thanks

 

[sbisteel]

AISC J2.1a - the effective area of groove welds are considered as the length of the weld times the effective throat.

The effective throat is shown on table J2.1 for groove welds, J2.2 for flare bevels.

 

[PBEIT]

Sbisteel,

I'm looking for the A_BM not A_w.

I think that it is just the thickness of the thinner connecting plate time the length of the weld.

Thanks

 

[sbisteel]

Sorry, totally focused on the title and not the text. It is the cross sectional area of the base metal, like you say.

 

[BUGGAR]

If I understand you, shouldn't the effective throat be specified with the weld callout. It's enclosed in parenthesis.

 

[wannabeSE]

PBedit - It sounds like load path will probably be fairly uniform in the 1/2" x 4' example and the area of the base metal is 2 in². Sometimes I wonder why this requirement is in J.2.5 when it is more thoroughly covered in J.4. Perhaps, this is included for times when the load path does not fit into the neat categories in J.4. You may want to look in the section titled "CONNECTING ELEMENT RUPTURE STRENGTH AT WELDS" in chapter 9 of the Steel Construction Manual (page 9-5 in the 13th and 14th edition). The equations in this section calculate the minimum base metal thickness to prevent shear rupture based on the capacity of fillet welds, but is would be easy to convert these for PJPs.