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Mechanics of Materials Lab. Lecture 15 Fatigue Mechanical Behavior of Materials Sec. 11.1-11.3 Jiangyu Li University of Washington. S-N Diagram. Safety Factor. Example.
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Mechanics of Materials Lab Lecture 15 Fatigue Mechanical Behavior of Materials Sec. 11.1-11.3 Jiangyu Li University of Washington Jiangyu Li, University of Washington
S-N Diagram Jiangyu Li, University of Washington
Safety Factor Jiangyu Li, University of Washington
Example 9.10 For AISI 4340 steel in Table 9.1, a life of 1.94x105 cycles to failure is calculated for the stress amplitude of sa=500 Mpa. Suggestion is made that parts of this type be replaced when the number of cycles applied reach 1/3 of the life. • What is the safety factors in life and in stress • Is the suggestion good? Jiangyu Li, University of Washington
Facture Mechanics Method of Fatigue Jiangyu Li, University of Washington
Crack Growth > > Jiangyu Li, University of Washington
Fatigue Life Jiangyu Li, University of Washington
Fatigue Crack Growth Rate Jiangyu Li, University of Washington
Crack Grow Rate Jiangyu Li, University of Washington
Crack Growth Rate Jiangyu Li, University of Washington
Effect of R Ratio Jiangyu Li, University of Washington
Example • For a bar subjected to 0<M<1200lb · in, Sut=185kpsi, Sy=170kpsi, Kic=74kpsi·in1/2, C=3.8 10-11 (in/cycle)/(kpsi·in1/2)m, m=3.0, a=0.004in. Estimate Nf. Jiangyu Li, University of Washington
Example Initial estimate, F=1 Jiangyu Li, University of Washington
Assignment Mechanical Behavior of Materials 11.3, 11.7 Jiangyu Li, University of Washington