TIG Welding Design Strength

[amecENG]

Can anyone provide me with an online resource for the strength of fillet welds made by TIG welding?

 

[connectegr]

Design strength will depend on base and filler metals. The technical name is GTAW - Gas Tungsten Arc Welding. What are you welding and what wire are you using?

http://www.FerrellEngineering.com

 

[amecENG]

I am trying to specify a weld to join a 3/16" thick steel angle to a 1/4" thick steel plate to transfer approx 40 kN parallel to the weld axis.

All the contractor has available at the site is a TIG (GTAW) machine. I am not sure what filler metal he has available but for now I am just looking for some design references/table similar to what is available in the steel code for arc welding for some common types of filler material.

Is there a way to pro-rate the weld shear resistance tables of the code for GTAW welds?

Thanks.

 

[Duwe6]

If he uses E-70S wire, with a 70,000# min. tensile [VERY standard c/s filler wire] the strength of the filler will be:

928# * [fillet size in 1/16's of an inch] * [length in inches] = 'working' of fillet. -formula from the AISC Structural Handbook-

Thus, a 1/4" fillet 2 inches long calcs as 4/16" in size =
928 * 4 * 2 = 7424# = 7.4 kips. Sorry, but i don't typically work in MKS; typical American in lbs-inches.

 

[connectegr]

General angles to plates, implies certain connection eccentricities. Duwe6's response is the straight shear capacity of a fillet weld. The design of the weld is independent of the welding process. GTAW is an acceptable process if the appropriate filler metal is used. For A36 or A572-50, 70ksi filler is correct as Duwe6 has stated.

http://www.FerrellEngineering.com

 

[amecENG]

OK Thanks for all your help.

I didn't realize that the design of the weld was independent of the welding process. I'll have to look into this some more but thanks again.

 

[Guest102023]

It is also independent of the actual strength of the deposited filler. It is based on the specified minimum strength of the filler metal classification, as given in AWS A5.xx standards. In this way additional conservatism is built in to structural design.

 

[Ron]

On-site GTAW welding can be problematic. You'll have to control wind conditions particularly, since shielding gas tends to get blown about in windy conditions, resulting in a poor quality weld.

Strength design of the weld is essentially independent of the process; however, constructability is affected by the selected process. Your application would likely be better served using SMAW. Check to see if your intended weld joint is pre-qualified under the process and that the welders are qualified under the process and conditions.