Consider the belt drive having a diameter of $150mm$ that is mounted on the

overhung end of a shaft, $30mm$ from the nearest bearing. The stepped shaft is

made of steel having $Su=965$MPa$(140$ksi$).$ The shaft diameter, d$,$ is $30mm.$

The bearing bore, $D,$ is $36mm.$ The fillet with a machined surface has a radius,

$r,$ of $3mm.$ What is the safety factor with respect to eventual fatigue failure of

the shaft? Ignore yielding.