For a given stress range of $700$Mpa, perform tasks below for each material,

Calculate initial stress intensity factor and determine if the crack will grow or not

If the crack will grow, determine if part meets the life requirement of $3,000$ cycles according to

given failure criteria below,

A$.1.$ Ka and $Kc>$ material fracture toughness $)$

B$.2.$ crack depth $>$ Maximum allowable crack depth $20mm$

C$.3.$ crack width $>$ Maximum allowable crack width: $60mm$

Which material do you select and why?

Given Information

Stress range at crack assessment, $()$:$700$Mpa

Crack plane depth : $20mm$

Crack plane width: $60mm$

Initial crack size, $a=c=0\mathrm{.}38mm$

Take $$ angle as $90$deg

Semi$-$elliptical surface crack

Crack Propagation Formulations

$\frac{da}{dN}=c{K}^m,Q=1+1\mathrm{.}464(\frac{a}{c}{)}^{1\mathrm{.}65}$

$K={}_s\sqrt[\phantom{2}]{\frac{a}{Q}f()},{}_z=[1\mathrm{.}13-0\mathrm{.}09(\frac{a}{c})][1+0\mathrm{.}1(1-sin{)}^2]$

$,f()=[si{n}^2+(\frac{a}{c}{)}^{2}co{s}^2{]}^{\frac{1}{4}}$