Specific crack enthalpy as material characterization parameter

Abstract In this study, the specific crack enthalpy (damage), considered a material characterization parameter according to crack layer theory, is discussed. The crack region and its accompanying damage become a crack layer. Fatigue crack propagation experiments were conducted on HT60 and HT80 steel. The specific enthalpy γ* of fracture due to ductile crack propagation in steel HT60 and HT80 has been calculated. The energy release rate and damage coefficients were determined at different stress ratios varying from R = 0.04 to 0.8. The crack layer translational resistance moment R1 has been determined. Because interpreting the data of crack propagation on two types of steel in the light of this theory reveals reasonable similarity, the need to set up experiments specifying the limitations and applicability of the theory is essential.