Answer:
The answer is below
Explanation:
Assuming that Y = 1.35
[tex]The\ plane\ strain\ fracture\ toughness\ K_{IC}= 24\ MPa ,stress(\sigma)=yield\ strength/2\\=495\ MPa/2=247.5\ MPa\\\\The\ maximum\ internal\ crack\ length\ allowable\ is\ calculated\ using:\\a_c=\frac{1}{\pi}(\frac{K_{IC}}{Y*\sigma} ) ^2=\frac{1}{\pi}(\frac{24\ MPA}{1.35*247.5\ MPA} )^2= 0.00164\ m\\\\a_c=1.64\ mm\\\\If\ the\ crack\ is\ internal\ then\ The\ maximum\ internal\ crack\ length\ allowable=2a_c=2*1.64\ m=3.28\ mm[/tex]