PSI - Issue 28

J. Serra et al. / Procedia Structural Integrity 28 (2020) 381–392

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Author name / Structural Integrity Procedia 00 (2019) 000–000

5. Conclusions Vibration analysis was performed in a finite element simulation and the vibration modes were identified. A stress linearization was performed for the critical vibration mode and mesh to determine the membrane and bending stresses. The influence of intrinsic manufacturing flaws in the railway gearbox housing durability was studied. Assessing the vibration modes, it was concluded that the component is subject to major deformations, and independently of the principal/ equivalent stress values being quite low, the existence of defects intrinsic to the manufacturing processes, causes serious structural integrity problems. The methodology developed in this work to predict the durability of the component presents excellent results, (these results have been confirmed by the service data available by courtesy of a railway company). It is concluded that the expected lifetime of the body of the gearbox housing is lower than the cover. The SIFR is higher in the body due to the presence of the welding and. The propagation direction of the crack influences highly the total number of cycles. Small differences in initial crack size could change drastically the expected lifetime of a component. From the results, it was also concluded that the values of stress intensity factor are dependent on the, crack propagation direction (θ), flaw position and zone were the cracks are located. And for a critical crack length of 1.75 mm the followed critical stress intensity factors were obtained: embedded flaw (2 mm under the surface) in the zones with welds and without welds were, for θ=85º, K= 125.733 MPam 1/2 and K= 18.895 MPam 1/2 ; a surface flaw in the zones with welds and without welds were, for θ=90º, K= 140.224 MPam 1/2 and K= 21.073 MPam 1/2 , respectively. References BS 7910:2013+A1:2015: BSI Standards Publication Guide to methods for assessing the acceptability of flaws in metallic structures. Darcis P., Santarosa D., Recho N., Lassen T., 2004. A fracture mechanics approach for the crack growth in welded joints with reference to BS 7910,” Eur. Conf. Fract. 15 - Adv. Fract. Mech. Life Saf. Assessments, pp. 1–8. Hu W., Liu Z., Liu D., Hai X., 2017. Fatigue failure analysis of high-speed train gearbox housings, Eng. Fail. Anal., vol. 73, 57–71. Infante, V., Branco, C. M., Brito, A. S., Morgado, T. L., 2003. A failure analysis study of cast Steel Railway Coupling Used for Coal Transportation. Engineering Failure Analysis, Elsevier Science Ltd.,10-4: 475-489. Kumar A., Jaiswal H., Pandey A., Patil P., 2014. Free Vibration Analysis of Truck Transmission Housing Based on FEA, Procedia Mater. Sci., vol. 6, no. Icmpc, 1588–1592. Moolwan C., Netpu S., 2013. Failure Analysis of a Two High Gearbox Shaft, Procedia - Soc. Behav. Sci., vol. 88, pp. 154–163. Morgado T., 2015. Fatigue Life Extension Study in Cast Steel Railway Couplings Used in Freight Trains. International Journal of Mechanical Engineering and Applications. Special Issue: Structural Integrity of Mechanical Components. Vol. 3, No. 2-1: 1-6. Morgado T., 2016. Failure of steel coupling used in railway transport. Handbook of Materials Failure Analysis with Case Studies From the Aerospace and Automotive Industries, chapter 20. Edited by Abdel Salam Hamdy Makhlouf and Mahmood Aliofkhazraei. Elsevier BH, Published: UK, 449-469. Morgado T., Branco C. M., Infante V, 2008. A failure study of housing of the gearboxes of series 2600 locomotives of the Portuguese Railway Company, Eng. Fail Anal., 15(1–2):154–64. Ottersböck M., Leitner M., Stoschka M., Maurer W., 2016. Effect of Weld Defects on the Fatigue Strength of Ultra High-strength Steels, Procedia Eng., vol. 160, no. ICMFM XVIII, pp. 214–222. Paris P.C., Erdogan F., 1963. A critical analysis of crack propagation laws, J. Basic Eng. 85 (4) 528–533. Seko Y., Imai Y., Mitsuya M., Oguchi N., Minami F., 2016. Effects of crack configuration and residual stress on fracture driving force for welded joint with embedded flaw, Procedia Struct. Integr., vol. 2, pp. 1708–1715. Sonsino C. M., 2005. Structural durability of cast aluminium gearbox housings of underground railway vehicles under variable amplitude loading, Int J. Fatigue, vol. 27 (8), 944–953. Zhang B., Tan A. C. C., Lin J., 2016. Gearbox fault diagnosis of high-speed railway train, Eng. Fail. Anal., vol. 66, 407–420. Zyl G. V., Al-sahli A., 2013. Failure analysis of conveyor pulley shaft, Biochem. Pharmacol., vol. 1, no. 2, pp. 144–155.