Question $2$

A solid square rod is cantilevered at one end. The rod is $0\mathrm{.}6$ m long and supports a completely reversing transverse load at the other end of $F=+-2kN.$ The material is AISI $1080$ hot$-$rolled steel.

a $-$ Evaluate the fatigue strength $Sf=$aNb if the rod must support the load for $104$ cycles $($take $kb=0\mathrm{.}85).$

b $-$ What dimension should the square cross section have for a factor of safety of $1\mathrm{.}5?($We neglect any stress concentrations at the support end$).$