Aerospace Engineering:

Problem $1(15$ Points$)$

You are conducting the failure analysis of a fatigue test article. In a complex part that broke during the test you see the photo below in the scanning electron microscope. Assuming the Paris equation is valid, what is the Beta factor for the part at the crack length given. $($For the scale on the photo, the $2$ U bar is $2$ micro inches $(2$xx$10-6$ inches$)$ long.$)$

Max stress is $20$ Ksi $,$ min stress is $5$ Ksi

m$=3\mathrm{.}0$

C$=2\mathrm{.}95$ xx$10-12($based on stress input in Ksi units, not psi$)$ a$=1\mathrm{.}5$

inches