Question $1$

For the following two homogeneous sections,

$($a$)$ find the positions of the plastic neutral axis and

$($b$)$ find the plastic moment capacity $($also called resistance$).$

$($c$)$ find the plastic section modulus.

All dimensions in mm $.$ The yield stress of the material is $450($N$)/($m$)$m$^(2).$

$($ii$)$

Answers: $($i$)$ Mp$=1314$kNm$,$S$=292000$mm$^(3)$;

$($ii$)$ Mp$=2722\mathrm{.}5$kNm$,$S$=6050000$mm$^(3)$;