Problem 8.32

Moving the 6 kip force to point b, I have to display a moment:

The 6 kip force itself can be broken into components, one of which results in a normal stress and the other a shearing stress:

I'll also compute the properties of the cross section, so that they are available later when I need them:

The area A_Q is that of half of the cross section - the part above the N.A.

At the top and bottom of the cross section (a and c), the normal stress arises from two terms and the shearing stress is zero (Q = 0):

At the center of the cross section (point b) only the P/A term applies: 2.05 ksi.

The shearing stress at b is:

Alternatively, the approximate relation could have been used.