Values for small a $/$ b and limits for $10\%$ accuracy:

$)(0\mathrm{.}4)(0\mathrm{.}6)(1\mathrm{.}5)(2)(1$

Fig. $1$: Stress intensity factors for three cases of cracked plates under tension

A tension member has width $b=40mm$ and thickness $t=10mm.$ An axial force $P$ is applied. The

member may contain an edge crack as deep as $a=8mm$ as in fig. $1$C$.$

a$)$ Estimate the force P at failure if the material is ASTM A$517-$F Steel

$)=187$Mpa$\sqrt[\phantom{2}]{m},{}_{YS}=(760$Mpa

b$)$ Estimate the force P at failure if the Material is AISI $4130$ Steel

$)=110$Mpa$\sqrt[\phantom{2}]{m},{}_{YS}=(1090$Mpa

c$)$ Which material is a better choice if the material was to be used in an engineering

application? Why?