Formulas: Strength Reductions for Members with Bolt Holes in the Tension Flange

Formula 1

(a) When $F_{u} A_{f n} \geq Y_{t} F_{y} A_{f g}$, the limit state of tensile rupture does not apply.

Formula 2

(b) When $F_{u} A_{f n}<Y_{t} F_{y} A_{f g}$, the nominal flexural strength, $M_{n}$, at the location of the holes in the tension flange shall not be taken as greater than

Equation F13-1

where

$\begin{aligned} A_{f g} & =\text { gross area of tension flange, calculated in accordance with Section B4.3a, } \\ & \text { in. }^{2}\left(\mathrm{~mm}^{2}\right)\end{aligned}$

$\begin{aligned} A_{f n} & =\text { net area of tension flange, calculated in accordance with Section B4.3b, in. }^{2} \\ & \left(\mathrm{mm}^{2}\right)\end{aligned}$

$F_{u}=$ specified minimum tensile strength, ksi (MPa)

$S_{x}=$ minimum elastic section modulus taken about the x-axis, in. ${ }^{3}\left(\mathrm{~mm}^{3}\right)$

$\begin{aligned} Y_{t} & =1.0 \text { for } F_{y} / F_{u} \leq 0.8 \\ & =1.1 \text { otherwise }\end{aligned}$

Found in

• PROPORTIONS OF BEAMS AND GIRDERS