Answer:
length of starter crack = 1.056
Explanation:
given data
temperature = 425 C
yield strength = 60%
Y parameter = 2.5
solution
we use here A 20 table so we get here value that is
Sy = 1360 MPa
Kic = 117.5 MPa [tex]\sqrt{m}[/tex]
so length of starter crack will be
a = [tex]\frac{1}{\pi } (\frac{Kic}{Y\times \sigma max})^2[/tex] .....................1
put here value and we will get
a = [tex]\frac{1}{\pi } (\frac{117.5}{2.5\times 0.6 \times 1360})^2[/tex]
solve it we get
length of starter crack = 1.056