PSI - Issue 50

I.G. Emel’yanov et al. / Procedia Structural Integrity 50 (2023) 57–64 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Therefore, as an illustrative example in Fig. 4 shows the falling curves of the ultimate strength depending on the operating time for different indicators of the kinetic coefficient m ∈ [2; 4; 8].

Fig. 4 Service life of metal structure in cycles: 1 – service life according to the linear hypothesis; curves 2 – 4 are constructed for m ∈ [2; 4; 8], respectively

Thus, using the model of cyclic degradation during the operation of this shell in contact with the support of the lodgment type, the service life of the shell is 142.7 · 10 7 cycles. And according to the hypothesis of linear damage summation, the service life is 151 · 10 7 cycles. 5. Conclusion The use of the contact problem to determine the maximum stresses in the zone of contact of the pipeline with a rigid cradle and the calculation for fatigue according to the model of cyclic degradation of the material makes it possible to estimate the service life of the pipeline structure. The use of the model of cyclic degradation of the material in comparison with the hypothesis of linear summation makes it possible to obtain a refined value of the service life of the metal structure. References Abdullah, L., Singh, S.S.K., Abdullah, S., Azman, A.H., Ariffin, A.K., 2021. Fatigue reliability and hazard assessment of road load strain data for determining the fatigue life characteristics. Engineering Failure Analysis 123, 105314, DOI: 10.1016/j.engfailanal.2021.105314. Callins, J.A., 1984. Failure of Materials in Mechanical Design: Analysis, Prediction, Prevention [in Russian], World, Moscow, pp. 624. Chang, K., 2015. Chapter 9 - Fatigue and Fracture Analysis, Computer-Aided Engineering Design, pp. 463-521, DOI: 10.1016/B978-0-12 382038-9.00009-0. D'Angela, D. , Ercolino, M., 2021. Acoustic emission entropy: An innovative approach for structural health monitoring of fracture-critical metallic components subjected to fatigue loading. Fatigue and Fracture of Engineering Materials and Structures 44, 4, pp. 1041-1058. DOI: 10.1111/ffe.13412. Emelianov I.G., Mironov, V.I., 2012. Durability of Shell Structures [in Russian], UrO RAN Publishing, Yekaterinburg, pp. 217. Emelyanov, I.G., 2009. Contact problems of the theory of shells [in Russian], Ural Branch of the Russian Academy of Sciences, Yekaterinburg, pp. 185. Grigorenko, Ya.M., Vasilenko, A.T., 1981. Theory of Shells of Varying Stiffness, Vol. 4 of the five-volume series Methods of Shell Design [in Russian], Naukova Dumka, Kyiv. Gusenkov, A.P., Kotov, P.I., 1988. Long-term and non-isothermal low-cycle strength of structural elements [in Russian], Mashinostroenie, Moscow, pp. 264. Li, S., Xie, X., Tian, Q., Zhang, Z., Cheng, C., 2021. A proposal on ultra-low cycle fatigue damage evaluation of structural steels. Theoretical and Applied Fracture Mechanics, 102973 In Press, Journal Pre-proof. DOI: 10.1016/j.tafmec.2021.102973. Manai, A., Al-Emrani, M., 2019. Fatigue assessment of metallic structures under variable amplitude loading. Procedia Structural Integrity 19, 12 18, DOI: 10.1016/j.prostr.2019.12.003. Manson, S.S., 1966. Thermal stress and low - cycle fatigue. McGraw - Hill Inc., US, pp. 404. Mironov, V.I., Emelyanov, I.G., Vichuzhanin, D.I., et al, 2019. A Method for Experimental Investigation of Degradation Processes in Materials [in Russian]. Diagnostics, Resource and Mechanics of materials and structures 2, pp. 16-27, DOI: 10.17804/2410-9908.2019.2.016-027.