Problem 10.58

For a W8 x 31 cross section,

A = 9.13 in²

r_y = 2.02 in (I'm using the smaller of r_x and r_y)

Also given are:

E = 29 x 10⁶ psi

L_e = 21 ft

a) For a yield stress of 36 ksi,

The slenderness ratio is . Since this is smaller than C_c, I use

Thus, .

b) For a yield stress of 50 ksi,

Now the slenderness ratio is larger than C_c and so I use

Thus, , not very different from part a.