In lab #$6$: Fatigue

Which one is not correct?

When a metal is subjected to repeated cycles of stress, it brakes down and fractures. This is the definition of fatigue.

Fatigue failure is brittle in nature and does not involve gross plastic deformation even in metals that behave in

a ductile manner under static loading

Fatigue starts from microscopic cracks and imperfections on the surface, that increase in size and lead to very high localized stress, and eventually sudden fracture.

When a metal is subjected to repeated cycles of stress, it keeps spinning faster.

In lab #$6$: Fatigue

Experiment was performed for $q,$

a round cantilevered sample with a point load at one end

a round cantilevered sample with distributed load

a round simply supported sample with distributed load

a round simply supported sample with a point load at one end