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Cumulated Microslip in Component Assembly of Engine and Gearbox
Technical Paper
2015-01-1737
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Today new automotive engine design is optimized in terms of mass. However, in terms of structural stiffness, optimizations mainly consider eigenfrequency criteria. But in assembly components with very low stiffness, cumulated microslip phenomena can occur when the structures are subject to cyclic loadings. In time and after a large number of cycles, macro-displacements can be observed between assembly components and then assembly failures will occur. Bush, plain bearing, roller bearing in conrod or in gearbox can be subject to this kind of problem.
In this paper, after a short description of various mechanisms which can cause microreptation phenomena, two types of cumulated microslip occurring in the engine and the gearbox are presented. Behavior specificities will be highlighted to remind how unusual cumulated microslips are. Based on field data, it appears that the probability of both phenomena occurring is extremely low. This implies that it is not appropriate to use devices concerned by this problem in order to reproduce and to investigate the phenomenon. Moreover, to assess the phenomenon sensitivity with respect to certain parameters, it follows that specific test rigs have to be developed. To cope with the problem for gearbox and conrod, two specific test rigs have been designed and finalized. Their schematic description will allow to assess the delicate points of the tests.
Some results obtained on test rigs are detailed and demonstrate that the mechanical behavior of cumulated microslip is quite complex. Friction phenomena in interface assembly appear to be a key characteristic. For example, significant friction variations with respect to time and slip displacement have been observed.
Authors
Citation
Ligier, J., Benoit, M., and Damaz, S., "Cumulated Microslip in Component Assembly of Engine and Gearbox," SAE Technical Paper 2015-01-1737, 2015, https://doi.org/10.4271/2015-01-1737.Also In
References
- Merritt , D. and Zhu , G. The Prediction of Connecting Rod Fretting and Fretting Initiated Fatigue Fracture SAE Technical Paper 2004-01-3015 2004 10.4271/2004-01-3015
- Sadwinsli M.P. , Farris T.N. Mechanics of Fretting Fatigue Crack Formation Wear 198 1996
- Hupperich P. The Development of the General Electric GEVO Engine CIMAC Congress Kyoto (Japan) 2004
- Antoni N. Phénomène de microreptation des assemblages mécaniques Thèse de l'Université de Savoie Chambéry France Novembre 2005
- Ligier J.-L. , Baron E. Acyclisme et Vibrations Technip 2002
- Antoni N. , Nguyen Q.-S , Ligier J.-L. On the cumulative microslip phenomenon European Journal of Mechanics A/Solids 26 2007 626 646
- Antoni N. , Ligier J.-L. Asymmetric friction: Modelling and experiments Int. J. Eng. Sci. 2007
- Ligier J.-L. , Antoni N. Cumulative microslip in conrod big end bearing system ASME May 8-10 2006
- Liang J. , Fillmore S. , Ma O. An extended bristle friction force model with experimental validation Mechanism and Machine Theory 56 October 2012 91 100
- Ferrero J. F. , Barrau J.-J. Study of dry friction under small displacements and near-zero sliding velocity Wear 209 1-2 322 327 1991
- Berthoud P. , Baumberger T. Shear stiffness of a solid-solid Multicontact interface Proc. R. Soc. Lond. A 454 1998 1615 1634
- Marmorini L. , Baldini A. , Bertocchi E. , Giacopini M. , Rosi R. al. On the loosening mechanism of a bush press-fitted in the small end of a connecting rod Proc. IMechE Part D. J. Automobile Engineering 2011 226 312 324
- Timoshenko S. P. , Goodier J. N. Theory of Elasticity McGraw-Hill 3rd 1970
- Stievenard A. , Ligier J-L. A simplified approach to predict sensitivity factors for the small end conrod of sports car engines 12th EDF/Pprime Workshop: Futuroscope October 6 & 7 2013
- Damaz S. Analyse d'un phénomène de microreptation et élaboration d'un banc d'essai dédié Internal report, Engineering school Mines de Douai 2014