A metal rod, 20 mm diameter, is tested in tension (force applied axially). The total extension over a length of 80 mm is 3.04 x 102 mm for a pull of 25 kN. Calculate the normal stress, normal strain and modulus of elasticity (Young's modulus), assuming the rod is linear elastic over the load range.

Respuesta :

Answer:stress=79.56MPa

strain=[tex]3.8\times 10^{-4}[/tex]

Young Modulus=209.36 GPa

Explanation:

Given data

d=20 mm

Length[tex]\left ( L\right )[/tex]=80mm

[tex]\Delta {L}[/tex]=[tex]3.04\times 10^{-2}[/tex]mm

Load=[tex]25\times 10^{3}[/tex]N

[tex]\left ( i\right )[/tex]

Stress=[tex]\frac{Load\ applied}{cross-section}[/tex]

Stress=[tex]\frac{25\times 10^{3}}{314.2}[/tex]

Stress=79.56MPa

[tex]\left ( ii\right )[/tex]

Strain=[tex]\frac{Change\ in\ length}{Length}[/tex]

Strain=[tex]\frac{3.04\times 10^{-3}}{80}[/tex]

Strain=[tex]3.8\times 10^{-4}[/tex]

[tex]\left ( iii\right )[/tex]

young modulus[tex]\left ( E\right )[/tex]=[tex]\frac{Stress}{Strain}[/tex]

E=[tex]\frac{79.56\times 10^{6}}{3.8\times 10^{-4}}[/tex]

E=209.36GPa