Derivation of Table 10-10a of AISC Manual (14th ed.) 1

[Pororo]

I'm trying to derive the values presented in Table 10-10 of the AISC manual. The limit states that I've considered (as stated in the commentary before the table) were bolt shear, bolt bearing, shear yielding, shear rupture, block shear, and weld shear.

The highlighted values in YELLOW below are the ones that I can already derive with the exact values. At those conditions, block shear failure governs. However, when I try to derive the values highlighted in RED, I can't seem to get the values. Since for both 3/8 and 7/16 plate thicknesses, the values are the same, it should mean that the possible governing limit states would only be bolt shear and weld shear (excluding the limit states factoring plate thickness).

Now, for bolt shear, I also considered the eccentricity as stated in 10-9. For weld shear, the values were very far from the values written in the table.

I hope you could help me out. Thank you!

Table 10-10a:

Table 10-9:

My Solution (for n = 12, Group A, Thread N, SSLT, tp = 3/8, ASD):

EDIT: Tabulated values have e = 3 in, giving C = 11.3, still far from tabulated values.

 

[nutte]

The eccentricity should be a/2, or 1.75". That makes C=11.6.

Your 84 ksi bolt shear is wrong. You should be using 54 ksi (for A325 bolts, threads included in shear plane). That will give you 138 kips. Use a=3" and you'll get 139 kips.

Note that these tables do not check weld shear. The weld is sized to develop the full plate strength, so if the plate works, the weld works.

 

[JAE]

Pororo,
I'm just curious. You've posted several of these questions: "I'm trying to derive the values in Table X"

Why are you going through the derivation of all these tables? Just to confirm for yourself that they are reliable? Or are you writing software based on these types of table uses?

Again - just curious.

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[Pororo]

Hello @JAE,

Haha you got me. I'm a Structural Designer trainee for connection design. I was tasked to derive the values of the tables so that I would know how the values were calculated, the limitations of the tables, and the assumptions used in the tables.

 

[Pororo]

Thanks @nutte for your input. Very much appreciated. I very rarely used this forum before 'til now so I don't know how to tag (if ever it's possible).