An Experimental Study of Friction and Lubrication in Hip Prostheses

1979 ◽  
Vol 8 (3) ◽  
pp. 153-159 ◽  
Author(s):  
J O'Kelly ◽  
A Unsworth ◽  
D Dowson ◽  
V Wright
Keyword(s):  
Experimental Study ◽  
Total Joint Replacement ◽  
Frictional Resistance ◽  
Clinical Situation ◽  
Hip Prostheses ◽  
Hip Function ◽  
Lubricant Viscosity ◽  
Film Lubrication ◽  
Fluid Film Lubrication

McKee-Farrar, Charnley and Muller prostheses have been studied in a hip function simulator using a range of silicone fluids as lubricants. Frictional resistance was measured continuously while the joints were subjected to dynamic loading. It was observed that the lubricant viscosity was very important to the mode of lubrication prevailing and that for viscosities in excess of 0.1 Pas, full fluid film lubrication was achieved. At viscosities which were less than this, mixed lubrication resulted These results can be extrapolated to the clinical situation where it was found that after hip surgery for total joint replacement, the synovial fluid produced around the prosthesis had a viscosity which was less than 0.1 Pas, and therefore could not give the most advantageous lubrication in these joints in vivo.

scholarly journals State of the art of friction modelling at interfaces subjected to elastohydrodynamic lubrication (EHL)

Friction ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 207-227
Author(s):  
Zhuming Bi ◽  
Donald W. Mueller ◽  
Chris W. J. Zhang
Keyword(s):  
State Of The Art ◽  
Computational Modelling ◽  
Elastohydrodynamic Lubrication ◽  
Contact Surfaces ◽  
Friction Prediction ◽  
Hydrodynamic Behaviors ◽  
Lubricant Viscosity ◽  
Film Lubrication ◽  
Friction Modelling ◽  
Fluid Film Lubrication

AbstractElastohydrodynamic lubrication (EHL) is a type of fluid-film lubrication where hydrodynamic behaviors at contact surfaces are affected by both elastic deformation of surfaces and lubricant viscosity. Modelling of contact interfaces under EHL is challenging due to high nonlinearity, complexity, and the multi-disciplinary nature. This paper aims to understand the state of the art of computational modelling of EHL by (1) examining the literature on modeling of contact surfaces under boundary and mixed lubricated conditions, (2) emphasizing the methods on the friction prediction occurring to contact surfaces, and (3) exploring the feasibility of using commercially available software tools (especially, Simulia/Abaqus) to predict the friction and wear at contact surfaces of objects with relative reciprocating motions.

The Effect of Bearing Properties on the Eigenvalues of a Rotordynamic System

2005 ◽  
Author(s):  
Jerry H. Ginsberg ◽  
Benjamin B. Wagner
Keyword(s):  
Rotation Rate ◽  
Damping Ratio ◽  
Cross Sectional ◽  
Campbell Diagram ◽  
Bearing Clearance ◽  
Modal Damping Ratio ◽  
Modal Damping ◽  
Lubricant Viscosity ◽  
Film Lubrication ◽  
Fluid Film Lubrication

This work examines how the natural frequencies and modal damping ratios of a shaft/rotor system are affected by changes in lubricant viscosity and bearing clearance. The analysis considers a uniform elastic shaft with a single rigid rotor mounted away from mid-span, and supported by fully cavitated, π-film, short-length, plain journal bearings. The transverse displacements and cross-sectional rotations are described by Ritz series, and standard fluid film lubrication theory is used to describe the forces generated by the bearings. The clearance and lubricant viscosity are independently adjustable at each bearing. A Campbell diagram, which depicts the imaginary part of the systems eigenvalues as a function of rotation rate, is used to identify critical speeds for the nominal system. With the rotation rate held fixed at a critical value, lubricant viscosity and bearing clearance are allowed to vary, and the fluctuations of natural frequency and modal damping ratio are evaluated.

Synergistic Effects of Implant Macrogeometry and Surface Physicochemical Modifications on Osseointegration: An In Vivo Experimental Study in Sheep

2019 ◽  
Vol 29 (4) ◽  
pp. 295-302 ◽  
Author(s):  
Edmara T. P. Bergamo ◽  
Paula G. F. P de Oliveira ◽  
Ryo Jimbo ◽  
Rodrigo Neiva ◽  
Nick Tovar ◽  
...  
Keyword(s):  
Experimental Study ◽  
Synergistic Effects

Bone heating and implant removal using a high‐frequency electrosurgical device. An in vivo experimental study

2021 ◽  
Author(s):  
Atsushi Kawamura ◽  
Yosuke Akiba ◽  
Masako Nagasawa ◽  
Makiko Takashima ◽  
Yoshiaki Arai ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Frequency ◽  
Implant Removal

The Effect of Irrigation Power and Ureteral Access Sheath Diameter on the Maximal Intra-Pelvic Pressure During Ureteroscopy: In Vivo Experimental Study in a Live Anesthetized Pig

2019 ◽  
Vol 33 (9) ◽  
pp. 725-729 ◽  
Author(s):  
Yasser A. Noureldin ◽  
Panagiotis Kallidonis ◽  
Panteleimon Ntasiotis ◽  
Constantinos Adamou ◽  
Evangelos Zazas ◽  
...  
Keyword(s):  
Experimental Study ◽  
Ureteral Access Sheath ◽  
Access Sheath ◽  
Pelvic Pressure

Preparation of Protamine Cationic Nanobubbles and Experimental Study of Their Physical Properties and In Vivo Contrast Enhancement

2013 ◽  
Vol 39 (11) ◽  
pp. 2147-2157 ◽  
Author(s):  
Hai-Peng Tong ◽  
Luo-Fu Wang ◽  
Yan-Li Guo ◽  
Lang Li ◽  
Xiao-Zhou Fan ◽  
...  
Keyword(s):  
Experimental Study ◽  
Physical Properties ◽  
Contrast Enhancement

Mechanism of Boundary Lubrication and the Edge Effect

1965 ◽  
Vol 87 (3) ◽  
pp. 735-739 ◽  
Author(s):  
Y. Tamai ◽  
B. G. Rightmire
Keyword(s):  
Thin Film ◽  
Acid Solution ◽  
Palmitic Acid ◽  
Boundary Lubrication ◽  
Frictional Resistance ◽  
Copper Surface ◽  
Bulk Liquid ◽  
Attraction Force ◽  
Thin Film Lubrication ◽  
Film Lubrication

Experimental work was carried out on the boundary lubrication of a copper-copper couple with pure cetane, palmitic acid solution of cetane, and some other organic materials. The purpose was to get information about α and μlube, which appear in the friction equation: μ=αμsolid+(1−α)μlube, by using two different kinds of copper surface, a clean surface, and an oxidized surface. α was found to be small with palmitic acid solution, and the estimated shear strength of palmitic acid was high under the examined condition. α and μlube seemed to be properties which are independent of each other. α is closely related to the attraction force between the lubricant and the substrate, whereas μlube is related to the complexity of molecular structure of the lubricant. A comparison was made of bulk-liquid and thin-film lubrication. μlube was smaller in thin-film lubrication than it was in bulk-liquid lubrication. This suggests that the frictional resistance may be partly contributed by liquid in the edge space around the real contact.

Paper 3: Recent Developments in Fluid Film Lubrication Theory

1967 ◽  
Vol 182 (1) ◽  
pp. 36-50 ◽  
Author(s):  
T. Lloyd ◽  
H. McCallion
Keyword(s):  
Finite Difference ◽  
High Speed ◽  
Lubrication Theory ◽  
Fluid Film ◽  
Special Topic ◽  
Finite Difference Schemes ◽  
Great Activity ◽  
Wide Range ◽  
Film Lubrication ◽  
Fluid Film Lubrication

Developments in high-speed electronic computers have greatly influenced the progress in fluid film lubrication over the past ten years. Static and dynamic oil film parameters have been computed for a wide range of finite geometries, for hydrostatic and hydrodynamic bearings lubricated by compressible and incompressible lubricants. These are either sufficient in themselves or else act as a yardstick against which approximate formulas may be tested. Much use has been made of iterative finite difference schemes, which are particularly well suited to digital computers, and these methods are now more fully understood. Other methods of solution include direct inversion of finite difference matrices and solution by expression of the pressure by some infinite series, a finite number of terms of which give adequate representation. Besides the increase in design data available, there has been substantial progress through a re-examination of the effects of modifying some of the assumptions inherent in most of the available solutions of the Reynolds equation. These include the assumption of constant lubricant viscosity, of rigid surfaces and of laminar flow. Major progress has been witnessed in two fields. The interaction of the lubricant film with elastic boundaries has been shown to be of prime importance in highly loaded contacts such as gears. This has led to the development of the special topic of elastohydrodynamic lubrication theory. The applicability of gas bearings in such growing industries as computers, space vehicles and nuclear reactors has resulted in great activity and progress in this field.

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