Please enable JavaScript.
Coggle requires JavaScript to display documents.
Fatigue Failure (How to avoid it? (Uniform pieces, Avoiding stress…
Fatigue Failure
-
How to avoid it?
-
Avoiding stress concentrators, discontinuities
-
-
-
Cross section
Typical Macro-structure
The fatigue fracture start in a puntual point where the stress increase and produce a local overeffort traspasing the yield strenght with cycle work who increase the stress continuosly.
-
-
-
-
-
There is a region emanating from the site of the original microcrack that appears burnished and a separate that appears dull and rough looking like a brittle fracture.
The burnished region was the crack and often shows beachmarks. They are due to a starting and stoping of the crack growth and they surround the origin of the crack, usually at a notch of internal stress-raiser.
-
Griffith criteria
It states that a cyclic stress multiplied by the local stress concentration coefficient at the end of a crack will cause it to propagate with two conditions:
If the crack size is smaller than the critical size, the crack will grow steadily due to fatigue, until it reaches a critical size where it will collapse
-
-
Fracture Toughness
-
It is a very important material property since the occurrence of flaws is not completely avoidable in the processing, fabrication, or service of a material/component.
-
-
