Fatigue Failure

Fatigue Failure Points : Fatigue Failure Fatigue failure occurs as a result of repeated application of small loads which individually incapable of producing detectable plastic deformation. Eventually repeated loads because a macro cracks to open and spread across the piece. Since intensification occurs and ultimately a sudden, brittle fracture results. Ferrous metals alloys have a limiting value of repeated stress which can be applied and reversed indefinitely large number of cycles without casing failure. This stress is known a limit. Non-ferrous metals and alloys do not have known limiting stress value which failure will not occur if the cycle is repeated often enough. For these fatigue strengths are usually given as stresses for which failure can be expected to at 10, 10 or some other specie number of cycles of loading. The results of tests are usually plotter on semi log plots.