Adaptation of the high-cycle fatigue model for assessing the service life of metal structures of floating cranes

The article addresses the pressing issue of increasing the reliability of residual service life assessments for metal structures of floating cranes operating for long periods under significant static and cyclic loads.

The aim of the research is to develop and validate a methodology for estimating the residual service life of floating cranes based on an adapted mathematical model, considering the combined action of low- and high-cycle fatigue mechanisms under complex disproportionate loading.

The research is based on an integrated approach, including: analysis of the design features and operating conditions of floating cranes; A generalization of the fundamental principles of damaged environment mechanics and fatigue failure theories; mathematical modeling of damage accumulation processes using evolutionary equations that take into account kinematic hardening and loading history; finite element modeling of the stress-strain state of metal structures; numerical verification of the model based on experimental data for structural steels; and the development of a two-level methodology integrating global structural analysis and local analysis in hazardous areas. The authors prove the need to account for high-cycle fatigue and transient deformation phenomena, which are not considered in traditional elastic analysis models and can lead to non-conservative estimates.

The authors propose an adapted mathematical model of a damaged environment, developed in the works of Yu.G. Korotkikh and his scientific school as a methodological basis. This model, unlike classical approaches, considers the loading history, kinematic hardening, and the combined action of low- and high-cycle fatigue mechanisms. Moreover, the results of model verification using structural steels are presented, demonstrating its high accuracy in describing damage accumulation processes under multiaxial stress conditions.

The article demonstrates a comprehensive service life assessment methodology, integrating finite element analysis of the global floating crane structure and subsequent local stress-strain analysis using an adapted model. Therefore, the authors show that the proposed approach enables a transition from conservative estimates to predictions based on modeling the actual history of operational loads, thereby significantly improving the validity of decisions on extending the service life of critical engineering structures.

1. Volkov I. A., Igumnov L. А., Tarasov I. S. Evaluating fatigue life of materials and structures under low-cycle loading. Computational Continuum Mechanics. 2017;10(1):17–30. https://doi.org/10.7242/1999-6691/2017.10.1.2. EDN: ZEYCOZ. (In Russ.).

2. Cherniavsky O. F., Cherniavsky A. O. Description of the deformation properties of materials in low-cycle fatigue calculations. Bulletin of the South Ural State University. Series: Mathematics. Mechanics. Physics. 2021;13(3):53–61. https://doi.org/10.14529/mmph210307. EDN: GGRBFL. (In Russ.).

3. Volkov I. A., Korotkikh Yu. G. Uravneniya sostoyaniya vyazkouprugo-plasticheskikh sred s~povrezhdeniyami. Moscow, 2008. 424 p. ISBN 978-5-9221-0965-9. EDN: MUWRUX. (In Russ.).

4. Volkov I. A., Igumnov L. A., Kazakov D. A. [et al.]. Defining relations of transient creep under complex stress state. Problems of Strength and Plasticity. 2016;78(4):436–451. EDN: XEGSPD. (In Russ.).

5. Volkov I. A., Igumnov L. A., Kazakov D. A. [et al.]. A damaged medium model for describing the process of long-term strength of structural materials (metals and their alloys). Problems of Strength and Plasticity. 2017;79(3):285–300. EDN: ZGUZCB. (In Russ.).

6. Cao X., Zou L., Lu Ch. Augmentation method of fatigue data of welded structures based on physics-informed CTGAN. Fracture and Structural Integrity. 2025;72:162–178. https://doi.org/10.3221/IGF-ESIS.72.12. EDN: VUUYWV.

7. Kostrub V. A., Miroshnikov A. A. Analysis of stress-strain state of steel structure of cantilever truss crane. Vestnik Luganskogo gosudarstvennogo universiteta imeni Vladimira Dalya. 2022;7(61):81–84. EDN: UGWFUT. (In Russ.).

8. Volkov I. A., Tarasov I. S., Igumnov L. A. [et al.]. State equations of unsteady creep under complex loading. Journal of Applied Mechanics and Technical Physics. 2018;59(3):191–202. https://doi.org/10.15372/PMTF20180320. EDN: URHZBY. (In Russ.).

9. Yablokov A. S., Volkov A. I., Shishulin D. N. Evaluation of the stress-strain state and the fatigue life of metal floating crane KPL 16-30 on its actual, operational loading. Russian Journal of Water Transport. 2017;52:56–70. EDN: ZGPQJD. (In Russ.).

10. Volkov I. A., Ereev M. N., Korotkikh Yu. G., Tarasov I. S. A model of damaged medium for evaluating the durability of structures subjected to combined low- and high-cycle fatigue loading. Computational Continuum Mechanics. 2012;5(1):54–60. EDN: OWGKBL. (In Russ.).

11. Volkov I. A., Igumnov L. A. Vvedeniye v kontinual’nuyu mekhaniku povrezhdennoy sredy. Moscow, 2017. 304 p. (In Russ.).

12. Igumnov L. A., Volkov I. A., Shishulin D. N., Belov A. A. Methodology for substantiating the resource of responsible engineering facilities. Mechanics of Solids. 2026;1:215–231. https://doi.org/10.31857/S1026351926010115. EDN: ZGFUJP. (In Russ.).

13. Ravin A. A., Khrutsky O. V. Engineering methods for predicting the residual resource of the equipment. Vestnik of Astrakhan State Technical University. Series: Marine Engineering and Technologies. 2018;1:33–47. https://doi.org/10.24143/2073-1574-2018-1-33-47. EDN: YOQFAU. (In Russ.).

14. Yu W., Sun X., Chen X. From mechanism empirical to physics-informed: a comprehensive review of multiaxial non-proportional low-cycle fatigue life prediction. International Journal of Structural Integrity. 2025;16(5):1048–1091. https://doi.org/10.1108/IJSI-01-2025-0008.

15. Ge X., Zhang C., Liu G. [et al.]. A Fatigue Damage Accumulation Model Considering Load Interaction and Material Parameters Under Variable Load Conditions. Fatigue & Fracture of Engineering Materials & Structures. 2025;48(6):2518–2539. https://doi.org/10.1111/ffe.14624.

16. Lopez Leon J. M., O’Nora N., Gordon A. P. A Review of Multiaxial Fatigue Life Predictions Methods and a Novel Graphical User Interface. ASME Turbo Expo 2025: Turbomachinery Technical Conference and Exposition. 2025;V008T24A011. https://doi.org/10.1115/GT2025-154093.