1. Mechanics of Materials Lab
Lecture 23
Fatigue
Mechanical Behavior of Materials Sec
Jiangyu Li
University of Washington 1
Jiangyu Li, University of Washington

2. Facture Mechanics Method of Fatigue2
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3. Jiangyu Li, University of Washington
Crack Growth
>
> 3
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4. Jiangyu Li, University of Washington
Fatigue Life 4
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5. Fatigue Crack Growth Rate5
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6. Jiangyu Li, University of Washington
Crack Grow Rate 6
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7. Jiangyu Li, University of Washington
Crack Growth Rate 7
Jiangyu Li, University of Washington

8. Jiangyu Li, University of Washington
Example
For a bar subjected to 0<M<1200lb · in, Sut=185kpsi, Sy=170kpsi, Kic=74kpsi·in1/2, C= (in/cycle)/(kpsi·in1/2)m, m=3.0, a=0.004in. Estimate Nf. 8
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9. Jiangyu Li, University of Washington
Example
Initial estimate, F=1 9
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10. Jiangyu Li, University of Washington
Assignment
Mechanical Behavior of Materials
11.3, 11.7 10
Jiangyu Li, University of Washington