Flare-Bevel Groove Weld-AISC 13th ed.

[bdlc2k]

I am designing the exact weld shown on Pg 8-61 of 13ed of AISC manual. The load is a torsion of a HSS8x4x1/4, and I need to design the top weld for tension. From what I understand, equation Rn=0.6*F(EXX)*.7071*(D/16)*l is only for fillet welds. Anyone know what the tension weld strength equation is for Flare-Bevel Weld? Thanks.

 

[DWHA]

pg 16.1-100, eq J2-4 & j2-5. I normally take the (1.0 + sin^1.5x) as 1.0 conservatively.

For flare bevel, the difficulty is often determning the effective throat.

 

[nutte]

DWHA, the equation you reference is for fillet welds, not flare bevel groove welds.

The tensile strength of the flare bevel groove weld is found in Table J2.5. Rn=0.6*Fexx*Area of weld (don't forget to multiply by phi or divide by omega). The effective throat of the weld is figured in Table J2.2.

 

[dhengr]

The tension force is M/3.6" +/-, and this is divided by the length of your weld, to get a shear flow of lbs./inch on the weld. The tensile strength of the weld is {.6*F(EXX)}{the weld throat} and the weld throat for a fillet is {.707(D/16)}. Draw a full scale detail of your weld in that groove btwn. the plate and the HSS, and you can measure the throat, it is the shortest cross sectional dimension through the weld. Keep in mind that your welder will not likely get all the way down in that groove with good sound weld, and he has trouble getting good penetration into either piece of parent metal down there. The difficulty or uncertainty is that you tend to get a very poor weld quality at the root of the weld in that detail. A second poor condition is at the start and stop points in the length of the weld where weld quality can be inferior, and you may have some prying (stretching, twisting action) of the weld at this high stress location with the stress raisers caused by the inferior weld. It’s one thing if this is a static problem and quite another if it is a fatigue sensitive detail, but you must pay particular attention to the quality of the weld root in that detail, which leads to your effective weld throat, and account for it in your design. You can get cracking starting from the poor root condition.

 

[NS4U]

Be Careful- im not sure this is a prequalified weld by AWS