PSI - Issue 48

V.M.G. Gomes et al. / Procedia Structural Integrity 48 (2023) 142–148 Gomes et al/ Structural Integrity Procedia 00 (2023) 000–000

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4. Conclusions The quantification of the residual stress state in UIC parabolic leaf springs applied in freight wagons was carried out in this investigation. Two types of stresses were analyzed, assembly stresses and residual stresses by stress shot peening at two different points on the master leaf. The stress relief method together with electric extensometry was used to assess the level of stress due to the assembly of the leaf springs. According to the data collected by the acquisition system and strain gauges, the area closest to the ends is less stressed than the area located in the middle of the leaf. The same trend was found in the residual stress profiles obtained by the X-ray diffraction method. According to the depth profiles obtained, higher residual stresses are found in the middle zone of the master leaf. The obtained data were used to estimate a fatigue limit stress corrected for the compressive state due to the observed residual and assembly stresses. Considering the superposition principle increases in fatigue resistance of up to 56.4 % were obtained for the middle zone of the leaf and 31.4 % for the ends. Acknowledgements The authors thank MEDWAY (Maintenance and Repair), Research Projects: FERROVIA 4.0, with reference POCI-01-0247-FEDER-046111, co-financed by the European Regional Development Fund (ERDF), through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020), under the PORTUGAL 2020 Partnership Agreement; SMART WAGONS - DEVELOPMENT OF PRODUCTION CAPACITY IN PORTUGAL OF SMART WAGONS FOR FREIGHT with reference nr. C644940527-00000048, investment project nr. 27 and PRODUCING RAILWAY ROLLING STOCK IN PORTUGAL, with reference nr. C645644454 00000065, investment project nr. 55 from the Incentive System to Mobilising Agendas for Business Innovation, funded by the Recovery and Resilience Plan and by European Funds NextGeneration EU, and Doctoral Programme iRail - Innovation in Railway Systems and Technologies funding by the Portuguese Foundation for Science and Technology, IP (FCT) through the PhD grant (PD/BD/143141/2019). Additionally, the authors would like to express an acknowledgement to the technical team of the laboratory of mechanical tests, LET at FEUP, and the CFisUC, at UC, and express a special acknowledgement to the Python, Julia, and ANSYS community. References UIC, I. U. of Railways, Wagons – suspension gear – standardisation. 2007. D. Petrovic, Bizic, M. Gasic, and M. Savkovic, “Increasing the efficiency of railway transport by improvement of suspension of freight wagons.,” Promet-Traffic and Transportation, vol. 24, no. 6, pp. 487–493, 2012. DOI:10.7307/ptt.v24i6.1202 Gomes, V.M.G., De Jesus, A.M.P., Figueiredo, M., Correia, J.A.F.O., Calcada, R, Fatigue Failure of 51CrV4 Steel Under Rotating Bending and Tensile. In: Lesiuk, G., Duda, S., Correia, J.A.F.O., De Jesus, A.M.P. (eds) Fatigue and Fracture of Materials and Structures. Structural Integrity, vol 24. Springer, 2022, Cham. https://doi.org/10.1007/978-3-030-97822-8_36 Kaiser, B., The Effect of Shot Peening on The Fatigue Strength Of Spring Elements, Technical Article 87169, 1987 E. Mueller, Stress Peening – A Sophisticated Way of Normal Shot Peening, Journal of Materials and Engineering A, vol 9, 56-63, 2019, doi: 10.17265/2161-6213/2019.3-4.002. Malikoutsakis, M., Gakias, C., Makris, I., Kinzel, P, Müller, E., Pappa, M., Michailidis, N., and Savaidis, G., “On the effects of heat and surface treatment on the fatigue performance of high-strength leaf springs”, MATEC Web of Conference 349, 04007, 2021, doi:10.1051/matecconf /202134904007. Y. Yamada, Materials for Springs. Springer-Verlag Berlin Heidelberg, 2007, doi:10.1007/978-3-540-73812-1. Lawerenz, M. D., “Shot peening and its effect on gearing,” SAE: 841090, pp. 56–67, 1995, doi:10.4271/71028. Ammar, S., Ramesh, K. , Ma, I., Farah, Z., Vengadaesvaran, B., Ramesh, S., Arof,, A., Studies on SiO 2 -hybrid polymeric nanocomposite coatings with superior corrosion protection and hydrophobicity,” Surface and Coatings Technology, vol. 324, pp. 536–545, 2017. Huang, H., Niu, J., Xing, X., Lin, Q., Chen, H. and Qiao, Y. “Effects of the shot peening process on corrosion resistance of aluminum alloy: A review,” Coatings, vol. 12, no. 5, 2022, doi: 10.3390/coatings12050629. Wang, T., Tinsley, B., Patel, M., Shabana, A. A., “Nonlinear dynamics analysis of parabolic leaf springs usinc ANCF geometry and data acquisition.” Nonlinear Dyn 93, 2487–2515 (2018). https://doi.org/10.1007/s11071-018-4338-3. ASTM E860-07, “Standard test method for residual stress measurement by- X-ray diffraction for bearing steels”, 2020. Noyan, I. C., Cohen, J. B., Determination of strain and stress fields by diffraction methods, pp. 117–163, 1987, doi:10.1007/978-1-4613-9570 6_5.