Eccentric Weld Shearing

[KZSteel]

I'm trying to find the resistance of the welds on a shear tab. Table 3-34 of the CISC Handbook seemingly gives me exactly what I am looking for, but I have also seen the resistance calculated by using table 3-27 and setting k=0. This is what is done in the AISC Manual. Unfortunately, I do not acheive the same result. For example. For a length of weld l=152mm, size D=6mm, and a 12mm thick plate, eccentricity to bolt lines e/l=a=0.4, table 3-34 gives C'=0.935, which gives a resistance of P=0.925x152mm= 142kN. Table 3-27 gives C=0.222 which gives a resistance of P=0.222*6mm*152mm= 202kN.

Which is actually giving me the resistance of the welds?

-K

 

[BAretired]

Table 3-34 is the correct reference. According to my book, C'=0.941, so P = 143 kN, close enough to what you found.

Table 3-27 is for a different situation where the eccentricity of load is measured normal to the plates.

BA

 

[KZSteel]

Yes, but in the AISC Manual, the exact equivalent of table 3-27, has a note that says "Special Case: (Load not in plane of weld groups) Use C-Values for k=0" And shows a diagram exactly like the diagram portraying the shear tab case in the CISC Manual table 3-34; a pair of vertical welds with a load P at an eccentricity normal to the plane of the welds.