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The analysis of dynamically loaded flexible journal bearings using higher-order finite elements

An efficient and robust predictive technique has been developed for the analysis of dynamically loaded, flexible journal bearings using the finite element method. The work is in two parts. In the first part a fast predictive technique is developed for the analysis of dynamically loaded, rigid journal bearings. The finite element formulation of Reynolds equation is presented using both 3-node triangular and 8-node isoparamteric elements to model the lubricant film. The latter are shown to approximate the problem more closely using fewer nodal points and hence requiring fewer equations. The Gauss-Seidel over-relaxation method is used to solve the resulting system equations and the sparseness of these equations is exploited. Comprehensive results are presented for the Ruston and Hornsby 6VEB Mk ifi marine diesel engine connecting rod bearing. Two different time stepping methods are considered and the effects of incorporating various oil feed features in the analysis are also presented. The second part of the work deals with the flexible bearing problem. The method of carrying out the structural modelling and the way in which the structural compliance relationships are obtained is described. A fast matrix inversion technique used to obtain these relationships is also described. Based on the rigid bearing work 8-node isoparametric elements are used to model the lubricant film. Two methods are presented for coupling the structural and lubrication analysis. The first method, the under-relaxation method, although proving straightforward to implement is shown to be unsatisfactory for this particular problem due to to convegnence problems. The second method is the Newton-Raphson method which is shown to be highly convergent. The Newton-Raphson method is subsequently highly modified to produce a fast solution method. This is shown to be several orders of magnitude faster than any previously developed method making this technique viable as a general design tool rather than just providing benchmarks against which to compare simpler analysis techniques. Again results are presented for the Ruston bearing showing the effect upon the predicted performance of incorporating elasticity into the analysis.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:265309
Date January 1988
CreatorsMcIvor, James David Colin
PublisherKing's College London (University of London)
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttps://kclpure.kcl.ac.uk/portal/en/theses/the-analysis-of-dynamically-loaded-flexible-journal-bearings-using-higherorder-finite-elements(8cb1e4bc-41a7-4a66-bf72-5b5e93668509).html

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