Determination of the stress intensity factor based on thermodynamic parameters
https://doi.org/10.52170/1815-9265_2024_71_66
Abstract
The paper considers an approach to determining the stress intensity factor (SIF) in the fatigue crack tip based on the principles of thermodynamics. The proposed approach is based on the Vestergaard model – the change in the SIF ΔKI value per observation cycle (e.g., during the time a train passes over a bridge) is determined from the data on the stress state around the crack tip. Such data are obtained by infrared thermography using the Kelvin relationship between the change in the sum of principal stresses and the change in surface temperature near the crack tip. Knowledge of the crack length is not required to calculate the SIF.
The paper presents the results of experimental studies of fatigue crack development on a specimen simulating the operation of a section of a beam wall of a metallic span structure supported by a stiffener with a notch at the top of the weld. Such sections are characterized by the development of fatigue cracks of T-9 and T-10 types.
The paper discusses the conditions of application of infrared thermography method for determining the stress field around the crack tip, defined the boundaries of the stress selection area for calculating the SIF, as well as the requirements for improving the signal-to-noise ratio when using thermography.
The results of the study are presented in the form of comparison of SIF values for experimental specimen at different length of fatigue crack, calculated by the known method of linear fracture mechanics and the developed method based on thermodynamic approach, their good coincidence is shown.
About the Authors
L. Yu. Solovyov
Siberian Transport University
Russian Federation
Russian Federation
Leonid Yu. Solovyov, Associate Professor of the Bridges Department, Head of the Automated Control Systems and Design Department of the Siberian Research Institute of Bridges, Candidate of Engineering
Novosibirsk
R. V. Chernavin
Siberian Transport University
Russian Federation
Russian Federation
Roman V. Chernavin, Lecturer of the Graphics Department
Novosibirsk
References
1. Paris P. C., Erdogan F. Critical Analysis of Crack Propagation Laws. Journal of Basic Engineering; Transaction, American Society of Mechanical Engineers. 1963;(85):528–534.
2. Sedov L. I. Mechanics of Continuous Medium. Vol. 3. Moscow: Nauka; 1970. 568 p. (In Russ.).
3. Tikhomirov V. M., Tyrin V. P. Use of the method of scattered light for determination of the stress intensity factor K III in three-dimensional problems. Applied Mechanics and Technical Physics. 1990;31(3):167–170. (In Russ.).
4. Tikhomirov V. M. Determination of the stress intensity coefficients by the photoelasticity method in three-dimensional problems of fracture mechanics. Problems of Mechanical Engineering and Machine Reliability. 2004;(2):94–100. (In Russ.).
5. Lurie A. I. Theory of Elasticity. Moscow: Nauka; 1970. 940 p. (In Russ.).
6. Zarubin V. S., Kuvyrkin G. N. Mathematical Models of Continuous Medium Mechanics and Electrodynamics. Moscow: Bauman MSTU ed. N. E. Bauman; 2008. 512 p. (In Russ.).
7. Instruction on maintenance of artificial structures. Approved by the order of Russian Railways dated 02.10.2020 Nо. 2193/r. URL: https://mintrans.gov.ru/file/473937. (In Russ.).
8. Malikov M. Yu., Solovyov L. Yu., Nerovnykh A. A. Experimental studies of fatigue crack growth rate in welded structures of railway bridgesю. Bulletin of Siberian Transport University. 2023;(65):82–90. (In Russ.).
9. Solovyov L. Yu., Fedorenko V. A. Application of the thermal method of fatigue damage control in the welded structures of the road bridge spans. Roads and Bridges. 2022;(47):187–209. (In Russ.).
10. Solovyov L. Yu., Fedorenko V. A. Improvement of the method of fatigue crack characteristics estimation in the welded metal bridge structures by the thermal method. Roads and Bridges. 2022;(48):113–139. (In Russ.).
11. Solovyov A. L., Solovyov L. Yu., Fedorenko V. A. Certificate of Registration of Computer Programme RU. Programme for processing of thermographic records for detection of fatigue damage in welded structures of metal bridges IRWS: No. 2022610420: applied. 23.12.2021: published 12.01.2022. (In Russ.).
12. Diaz F. A., Patterson E. A., Tomlinson R. A., Yates J. R. Measuring stress intensity factor during fatigue crack growth using thermoelasticity/ Fatigue & Fracture of Engineering Materials & Structures. 2004;27(7):571–573.
13. Iziumova A. Yu., Plekhov O. A., Vshivkov A. N. [et al.]. Investigation of energy dissipation rate in the fatigue crack tip. Letters to the Journal of Technical Physics. Perm: A. F. Ioffe Physical-Technical Institute; 2014. Vol. 40, Iss. 18. P. 72–77. (In Russ.).
14. Fedorova A. Yu., Bannikov M. V., Plekhov O. A. Applications of the infrared thermography method for determination of the linear crack mechanics parameters. Vestnik of Perm National Research Polytechnic University. Mechanics. 2012;(2):214–225. (In Russ.).
15. Plekhov O., Palin-Luc T., Naimark O. [et al.]. Fatigue crack initiation and growth in a 35CrMo4 steel investigated by infrared thermography. Fatigue and Fracture of Engineering Materials and Structures. 2005;(28):169–178.
16. Chernavin R. V., Zharlikova S. S., Solovyov L. Yu. Experimental investigation of a stress field in a crack tip on the basis of thermodynamic parameters. Fundamental and Applied Problems of Transport. 2023;(9):63–71. (In Russ.).
17. Ito Y., Murakami Y., Hasebe N. [et al]. Ed. by Murakami Y. Handbook of stress intensity factors. Translation from English. Moscow: Mir; 1990. Vol. 1. 448 p. Vol. 2. 568 p. (In Russ.).
Review
For citations:
Solovyov L.Yu., Chernavin R.V. Determination of the stress intensity factor based on thermodynamic parameters. Bulletin of Siberian State University of Transport. 2024;(4):66-73. (In Russ.) https://doi.org/10.52170/1815-9265_2024_71_66
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