Numerical analysis of lubrication in an artificial hip joint

dc.contributor.advisorDe Vaal, Philip L.en
dc.contributor.emails22187822@tuks.co.zaen
dc.contributor.postgraduateRamjee, Shatish
dc.date.accessioned2013-09-07T12:39:18Z
dc.date.available2008-09-23en
dc.date.available2013-09-07T12:39:18Z
dc.date.created2008-04-11en
dc.date.issued2008-09-23en
dc.date.submitted2008-09-15en
dc.descriptionDissertation (MEng)--University of Pretoria, 2008.en
dc.description.abstractThe ageing population has become more active and live longer, these patients require hip replacement surgery at a younger age. Artificial hip implants, consisting of the acetabular cup and femoral head, affect the lives of many people, and the longevity of these implants pose significant concerns (rarely longer than 17 years). To help understand the lubricating performance of such a system, a hip joint model was built based on the Reynolds equation; the model developed simulated hydrodynamic lubrication. A steady-state angular rotation model was built whereby it was concluded that such motion would not support any load due to the anti-symmetric nature of the resultant pressure distribution (anti-symmetric about the axis of rotation). The pressure distribution from the steady-state rotation simulation contained a pressure source and sink which converged to the centre of the cup and whose pressure value increased in magnitude, as the eccentricity ratio increased. Infeasible results were obtained when the intermediary pressure constraint, allowing only positive pressure values, was implemented. The results obtained were not representative of the problem and it is recommended that this constraint not be implemented. The transient walking cycle model showed that a fluid with viscosity of 0.0015Pa.s is not sufficient to support a load in the walking cycle under conditions representative of hydrodynamic lubrication. Increasing the fluid viscosity promoted better results in the hydrodynamic model. Increasing the femoral head radius and decreasing the radial clearance between the components also improves the possibility of hydrodynamic lubrication. It is recommended that the model should be extended to investigate elasto-hydrodynamic lubrication. If possible, the effects of a boundary lubrication model should be investigated, as it is believed to be a major contribution to the lubrication of hip joints.en
dc.description.availabilityunrestricteden
dc.description.departmentChemical Engineeringen
dc.identifier.citationa 2008en
dc.identifier.otherE1061/gmen
dc.identifier.upetdurlhttp://upetd.up.ac.za/thesis/available/etd-09152008-133304/en
dc.identifier.urihttp://hdl.handle.net/2263/27954
dc.language.isoen
dc.publisherUniversity of Pretoriaen_ZA
dc.rights© University of Pretoria 2008 E1061/en
dc.subjectHip jointen
dc.subjectTransient modelen
dc.subjectHydrodynamic lubricationen
dc.subjectSteady-state modelen
dc.subjectReynolds equationen
dc.subjectBiotribologyen
dc.subjectUCTDen_US
dc.titleNumerical analysis of lubrication in an artificial hip jointen
dc.typeDissertationen

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