Mean Stress Effect Correction in Frequency-domain Methods for Fatigue Life Assessment

Two fatigue life calculation methods are presented. One defined in the time domain and the second one defined in the frequency domain – both supplemented with a mean stress effect correction. The method is verified on the basis of own results for the S355JR steel. The authors analyze six models for the designation of the probability density function (PDF) of stress amplitudes used in the calculation process. The results are presented in the form of probability distributions before and after PSD transformation and the calculated fatigue life's are being compared with the experimental ones in fatigue comparison graphs.