A fatigue damage accumulation method in low – cycle fatigue zone

A summation method of the fatigue damage in a low cycle fatigue zone is proposed in the paper. The method is based on a fatigue curve revolution, with the fatigue curve in the $\epsilon_{ac}-2N_f$ co-ordinate system as a base line. The low-cycle properties and parameters of a loading program are necessary for fatigue life calculations.

Experimental verification of the proposed hypothesis (one material, two types of loading: random and programmed) showed a satisfactory agreement between the test and calculation results. A comparative analysis between the calculation results obtained using the linear damage rule (LDR) and those resulting from the method proposed, showed several advantages of the latter one. These are; e.g., the fact that the results obtained are located in the safe fatigue life area, simplicity of the method and sensitivity to the parameters of a loading program.