PSI - Issue 65

D.G. Solomonov et al. / Procedia Structural Integrity 65 (2024) 275–281 D.G. Solomonov and M.Sh. Nikhamkin / Structural Integrity Procedia 00 (2024) 000–000

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Fig. 5. The variation of (a) θ ���� ��� , (b) θ ����� �� , (c) θmid, and (d) θmax with increasing load in a block The results obtained by using four different methods for processing the experimental data are consistent with each other. The discrepancy between the values of ε � obtained from the maximum and average stabilization temperatures is within 9%. Both options provide an overestimation of the values compared to standard fatigue tests. When we calculate using θ ���� � �� , the resulting value of ε � is closer to the fatigue tests. The scatter of the experimental values around the approximation by the coefficient of determination � �� is somewhat less than in the case of using the average temperature θ ���� ��� . The calculation of ε � based on the rate of temperature rise in the loading block for both maximum and average temperatures gives results that differ from standard fatigue tests by 13–14%. The dissipation by the coefficient � �� is somewhat less than in the case of using the average temperature θ ���� ��� . Table 1. The obtained fatigue limit values. Parameter ε � /εst Variance � �� θ ����� �� 0.175 9.4% 1.76 θ ���� ��� 0.190 18.8% 1.69 θmax 0.137 14.4% 1.77 θmid 0.181 13.1% 1.79 Standard fatigue tests 0.16 – – In general, the values ε � obtained by the IRT method are consistent with the results of previously conducted standard fatigue tests. The discrepancy for all the four options for processing the results lies within 18.8%.