Members required to resist both bending moments and an axial tensile force shall be proportioned such that:

1. $\frac{T_u}{T_r}+\frac{M_u}{M_r}\le 1.0$

   where

   Mr

   =

   ϕMp for class 1 and class 2 sections = ϕMy for class 3 and class 4 sections

2. $\frac{M_u}{M_r}-\frac{T_u{Z}_{pl}}{M_{r}A}\le 1.0$ for class 1 and class 2 sections,

   $\frac{M_u}{M_r}-\frac{T_u{Z}_e}{M_{r}A}\le 1.0$ for class 3 and class 4 sections

   where

   Mr

   =

   as defined in 13.5 or 13.6