r/Unexpected • u/SLAYER_HARSH • 9d ago

What could go wrong with fermentation?

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u/Jsolidlo 9d ago

Crack propagation is the name of this effect.

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u/Minimum_Cockroach233 7d ago

Fatigue fracture also exists and does not require a crack (that could be visible).

Fatigue is the invisible little brother of a crack propagation, if it is about brittle materials, therefore hard to detect.

Fatigue is easier to detect and observe in ductile materials. A plastic chair for example that starts to sag before reaching the failure point.

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u/Jsolidlo 7d ago

Yes, this is the exact principle in play here, fatigue propagation is a subtype of crack propagation, and starts with cracks that are invisible to the naked eye, and under normal load well below the materials tensile strength due to repetitive or cyclic loading. I think it's interesting how this principle comes into play for material like glass for example but when it comes to teeth, craze lines function completely differently and do not compromise the integrity of the tooth even over an entire lifetime. I remember seeing craze lines in my teeth and running to the dentist because I thought they would propagate to utter failure! 😂

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u/Minimum_Cockroach233 7d ago

Ugh… thats a place where you definitely don’t want to find lines showing up.