Reviewing Older Calcs (AISC 9th ED) question

[PSSC]

I have a copy of some calculations done by another engineer.
Anytime I can get calculations to look and learn from I try to get most I can from it.
I have a lot of respect for this engineer, and sadly he has passed away since the calculations were done so I can't ask him about this.
So I hope some one here can answer a question I have.

The calculation was using AISC 9the Ed Table J3.3 for Allowable Tension Stress Ft.
Here is what I am confused about.

for A325 from the table.
The calcs I am looking at show this;
Ft = [sqrt((44000^2)-4.39fv^2)]*area

The area is of the bolt.
fv is the shear stress on the bolt (psi).

I thought that the 44000 was psi, and (fv) was in psi so if you multiply by the area of the bolt you were getting a force.
The calcs then compare Ft to actual tension stress(ft) which is a psi.
So was multiplying by the area a mistake or am I missing something?

Thanks

 

[JedClampett]

I don't have the calculation in front of me, but it looks like a minor typo by the original engineer. Sometimes, at about 3:30 in the afterrnoon, things start to blur. If he multiplied a stress times an area, it's a force.
If that was the worse mistake I ever made, I would be very satisfied with myself.

 

[Hokie93]

If the calculations did indeed multiply the equation from Table J3.3 by the bolt area and then compare the allowable tensile stress, F_t, to the actual tensile stress, f_t, then that is a mistake. You are correct that multiplying F_t by the bolt area results in the allowable tensile force, not stress. Note that the AISC 9th edition steel manual, and all previous editions, was based on allowable STRESSES so it would have been likely that the engineer intended to compare bolt stresses (F_t versus f_t) rather than bolt forces.

Interestingly, the equation you quoted uses psi whereas the AISC Specification in the 9th edition manual uses ksi. I am guessing this engineer practiced before AISC switched from using psi to ksi in the Specification and preferred to work in psi rather than ksi.