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| Failure Mechanisms | |||||||||||||||||
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mean stress may not be zero for these cyclic loading situations. Some Stress
parameters are defined:
Stress range: σr = (σmax - σmin) Stress amplitude: σa = (σmax - σmin)/2 Mean stress: σm = (σmax + σmin)/2 Stress ratio: R = (σmax / σmin) . · For real-world fluctuating stress situations a random stress/time curve is more probable than the periodic curve. |
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| From: Callister, "Materials Science & Engineering," Wiley (1994) | |||||||||||||||||