Answer:
The correct answer is "[tex]K_c=6.0369 \ MPa\sqrt{m}[/tex]".
Explanation:
Given:
Maximum load,
P = 50,000 N
Crack length,
a = 3mm
or,
= 3×10⁻³ m
Diameter,
d = 32 mm
As we know,
⇒ Maximum stress, [tex]\sigma=\frac{P}{A}[/tex]
[tex]=\frac{50000}{(\frac{\pi}{4}\times 32^2)}[/tex]
[tex]=62.20 \ N/mm^2[/tex]
Now,
⇒ Fracture tougness, [tex]K_c=Y \sigma\sqrt{\pi a}[/tex]
On substituting the values, we get
[tex]=1\times 62.20\times \sqrt{3.14\times 3\times 10^{-3}}[/tex]
[tex]=6.0369 \ MPa\sqrt{m}[/tex]