Formulas: effective net area

Formula 1

plastic section modulus of the entire section, $Z=\Sigma\left|A_{i} d_{i}\right|$.

Formula 2

The area above the plastic neutral axis is $A / 2$; therefore, by definition $\bar{x}_{1}=Z_{x} / A$.

Formula 3

Thus, for use in calculating $U$, $\bar{x}_{1}=d / 2-Z_{x} / A$.

Formula 4

Using the definitions just discussed, but related now to the y-axis, yields $\bar{x}=Z_{y} / A$.

Found in

• EFFECTIVE NET AREA