13th International Conference on Fracture June 16-21, 2013, Beijing, China 10,000 100,000 1,000,000 1E7 100 1000 10000 100000 1000000 E (J.m-3.cycle-1) N f (cycle) Constant fatigue test stop without failure R2=0.94 log(Em d 1 )=-0.77log(Nf )+8.33 Em d 1 Figure 8: Em d1 -N curve by dissipated energyEm d1 method of 316L material (Rσ=0.2, f=14Hz). 4. Conclusion In conclusion, dissipated energy per cycle Em d1 is constant under traction-traction cyclic loadings during constant and various stress amplitude high cycle fatigue tests of 316L stainless steel while the material reached a stabilized thermo-mechanical state (5% of total fatigue lifetime). Dissipated energy versus fatigue lifetime fitting curve shows the same pattern as the traditional stress versus fatigue lifetime curve. Further studies and specific microstructural analysis are still required to better understand the correlation between the dissipated energy and the microstructural material state. Acknowledgements The work is partially supported by CSC(visiting scholarship) and NSFC(51175160). And I also especially acknowledge the supervision of Prof. Fabrice PIERRON and Dr. Francois MAQUIN in LMPF, ENSAM in France. 9
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