Generalization of Coffin-Manson relation in connection with the low-cycle fatigue in the temperature range 20-300 o C

The low-cycle fatigue phenomenon in the framework of plastic deformation is studied considering the temperature parameter. The experimental results obtained for the plastic strain Δεp (1-7%), in the temperature range 20-300 o C are examined. The conclusion is that the lifetime, expressed by the number of stress cycles, Nf, is given by the relation Nf = C exp(-A/T)(Δεp)β+αΔT, where T is the absolute temperature, Δεp is double of plastic deformation amplitude, and C, A, β, and α are material constants. This relation can be interpreted as being the generalization of a relation, known in literature as the 'Coffin-Manson relation', but which does not include the temperature parameter. The validation of this relation can be done either on the results presented in this paper or an those published in literature. (Author)