PSI - Issue 39

Aljaž Ignatijev et al. / Procedia Structural Integrity 39 (2022) 89 – 97 Author name / Structural Integrity Procedia 00 (2019) 000–000

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work. The experimental testing was done on a custom made back to back gear testing rig. Based on the obtained computational and experimental results the following conclusions can be made: • The existing standardised procedure for determination the load capacity of sintered gears (i.e. AGMA Standard), requires calculation of many influential factors that are mainly dependent on the geometry of a gear. Here, the appropriate computational analysis may be used to replace this procedure and determine the stress and strain field in a gear tooth root numerically. Usually, dies for sinter-press technology are made by wire-EDM and at least a 2D contour exists, which can be used for swift preparation of a FEM model. • Although some fatigue data for sintered steels can be found in the literature, experimental testing of an exact material is preferred, because mechanical properties can be affected significantly by many variables: Density, sintering temperature and time, type and quantity of lubricant, ratio of alloying elements and additional heat treatment. • The obtained computational results for the total fatigue life (a sum of the crack initiation and crack propagation period) were found to be comparable to the available experimental results. However, the proposed computational model was found more conservative which is probably due to the assumed material parameters and precision of the measurements by experimental testing. • If compare the crack path in a gear tooth root, the position of the initial crack in a gear tooth root and the subsequent crack growth path was obtained very similar for both computational and experimental study. Acknowledgements The authors acknowledge the financial support of the Research Core Funding (No. P2-0063) from the Slovenian Research Agency. References Šori M., Vuherer T., Glodež S., Fatigue and fracture parameters of diffusion alloyed Cu –Ni–Mo sintered steel, Engineering Fracture mechanics, vol. 153, pp. 278-288, 2016. Dowling N.E., Mechanical Behaviour of Materials, Prentice Hall, New Jersey, 1999. Dizdar S., High-performance sintered-steel gears for transmissions and machinery: A critical review, Gear Technology, 60 − 65, 2012. Dlapka M., Danninger H., Gierl C., Klammer E., Weiss B., Khatibi G., Fatigue Behaviour and Wear Resistance of Sinter-Hardening Steels, International Journal of Powder Metallurgy, 48, 49–60, 2012. Flodin A., Brecher C., Gorgels C., Rothlingshofer T., Henser J., Designing powder metal gears, Gear Solutions, pp. 26 − 35, 2011. Glodež S., Šori M., Vučković K., Risović S., Determination of Service Life of Sintered Powder Metallurgy Gears in Regard to T ooth Bending Fatigue, Croat. j. for. eng., vol. 39, no. 1, pp. 129 − 137, 2018. Glodež S., Šori M., Verlak T., A Computational Model for Bending Fatigue Analyses of Sintered Gears, Journal of Mechanical En gineering, vol. 60, no. 10, pp. 649 − 655, 2014. Glodež S., Flašker J., Dimenzioniranje na življenjsko dobo: znanstvena monografija. Maribor: University of Maribor Press, 2006. (In Slovene) Lawcock R., Rolling-contact fatigue of surface-densified gears, International Journal of Powder Metallurgy, 42, 17–29, 2006. Straffelini G., Benedetti M., Fontanari V., Damage evolution in sinter-hardening powder-metallurgy steels during tensile and fatigue loading, Materials & Design, 61, 101–108, 2014. Šori M., Computational model for bending strength determination of sintered gears, doctoral dissertation. Maribor: University of Maribor Press, 2015.