Question

The plastic modulus of a section is
$4.8\times {10}^{-4}{m}^3$
The shape factor is 1.2. The plastic moment capacity of the section is 120 kNm. The yield stress of the material is ______.

• A. 240 MPa
• B. 300 MPa
• C. 250 MPa
• D. 100 MPa

Answer 1

The correct option is C 250 MPa

$Z_p=4.8\times {10}^{-4}{m}^3$
$M_p=120kNm$

We know that,
$M_p={\sigma }_y\times Z_p$

$\Rightarrow {\sigma }_y=\frac{120\times {10}^6}{4.8\times {10}^{-4}\times {10}^9}=250N/m{m}^2$