THE EFFECT OF THE COEFFICIENT OF FRICTION ON THE BIOMECHANICS OF CONTACT IN HIP ENDOPROSTHESIS

Tribologia ◽  
2017 ◽  
Vol 273 (3) ◽  
pp. 137-146
Author(s):  
Anna M. RYNIEWICZ ◽  
Tomasz MADEJ ◽  
Wojciech RYNIEWICZ ◽  
Łukasz BOJKO ◽  
Mieczysław CHOROMAŃSKI
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Hip Joints ◽  
Hip Endoprosthesis ◽  
Replacement Surgery ◽  
Hip Replacement Surgery ◽  
The Coefficient Of Friction ◽  
Materials Used ◽  
Two Parameters ◽  
Selection Of

Hip replacement surgery, by introducing a specific replacement head on the stem and cup, completely changes the conditions of co-operation typical for the biological correct pair. The clinical selection of endoprosthesis, apart from other conditionings, involves a dilemma between the choice of a rigid tribological node and the selection of a susceptible bearing cushioning the locomotive loads. The aim of the study is to evaluate the coefficient of friction and wear resistance of materials used for sliding contact in the endoprostheses of hip joints. On the basis of the conducted tests, it can be stated that, in the selection of material for cups of endoprosthesis, the wear resistance is important, and the coefficient of friction in contact head and cup in the prosthesis is less important. The presence of significant disproportions between the two parameters of the tribological process proves that the biomaterial is less useful on the cup. In the assessment of cooperation in the endoprosthesis, simulations of the contact of structural elements are useful, because, on that basis, in the correlation with tribological parameters, one can make conclusions about the distribution of stresses and displacements that may determine the lifetime of the implant.

FRETTING CORROSION STUDIES OF MATERIALS USED FOR ELEMENTS OF HIP JOINT ENDOPROSTHESES

Tribologia ◽  
2018 ◽  
Vol 281 (5) ◽  
pp. 143-151 ◽  
Author(s):  
Agnieszka WIELOWIEJSKA-GIERTUGA ◽  
Tomasz WIŚNIEWSKI ◽  
Rafał RUBACH
Keyword(s):  
Corrosion Resistance ◽  
Fretting Corrosion ◽  
Hip Joints ◽  
Hip Endoprosthesis ◽  
Corrosion Studies ◽  
Pin On Disc ◽  
Materials Used ◽  
Damage Processes ◽  
Optimized Conditions ◽  
Selection Of

The operational durability of a hip endoprosthesis depends, among others, on the intensity of the damage processes of kinematic junction elements caused by fretting corrosion processes. In the article, the results of comparative studies on the fretting corrosion resistance of alloys commonly used for hip joints, i.e. Ti6Al4V, CoCrMo, stainless steel M30NW, and 316LVM, are presented. The research was carried out by means of a tribological pin-on-disc tester working in reciprocating motion, integrated with a potentiostat equipped with a triac electrode. The tribosystem was a pin pressed by a constant force to a reciprocating disc with a certain amplitude and frequency. The tests were carried out in a medium of aqueous bovine serum heated to 37°C. The conducted comparative tests of the above mentioned materials will allow selection of the best material combination in terms of tribological and fretting corrosion resistance. Under optimized conditions, the modified oils obtained a needed appropriate viscosity class.

scholarly journals DETERMINING THE COEFFICIENT OF FRICTION OF WOOD-BASED MATERALS FOR FURNITURE PANELS IN THE ASPECT OF MODELLING THEIR SHREDDING PROCESS

Wood Research ◽  
2021 ◽  
Vol 66 (5) ◽  
pp. 789-805
Author(s):  
MATEUSZ KUKLA ◽  
ŁUKASZ WARGUŁA ◽  
ALEKSANDRA BISZCZANIK
Keyword(s):  
Coefficient Of Friction ◽  
Kinetic Coefficient ◽  
Drive Unit ◽  
Base Surface ◽  
The Coefficient Of Friction ◽  
Kinematic Coefficient ◽  
Cutting Processes ◽  
Static Coefficient Of Friction ◽  
Static Coefficient ◽  
Selection Of

In order to improve the power selection of the drive unit for the shredding machines,theauthors determine the values of friction coefficients used in the cutting force models. These values consider the friction between steel and such wood-based materials as chipboard, MDF and OSB. The tests concern laminated and non-laminated external surfaces and surfaces subjected to cutting processes. The value of the coefficient of friction for the tested materials is in the range: for the static coefficient of friction 0.77-0.33, and for the kinetic coefficient of friction 0.68-0.25. The highest values of the static and kinematic coefficient of friction were recorded for MDF (non-laminated external surface) and they were equal respectively: 0.77 and 0.68. In turn, thesmallest values of the discussed coefficients were recorded for chipboard (laminated external wood-base surface), which were at the level of 0.33 and 0.25, resp.

DISPLAZINIŲ KLUBŲ SĄNARIŲ ENDOPROTEZAVIMO ATOKŪS REZULTATAI

2015 ◽  
Vol 25 (1) ◽  
pp. 39-43
Author(s):  
Gediminas Degutis ◽  
Petras Butėnas ◽  
Liudvikas Kervys
Keyword(s):  
Acetabular Component ◽  
Hip Replacement ◽  
Hip Dysplasia ◽  
Lateral Displacement ◽  
Late Results ◽  
Average Response Rate ◽  
Hip Joints ◽  
Replacement Surgery ◽  
Hip Replacement Surgery ◽  
Results Of Treatment

Purpose: To evaluate the late results of the patients undergone total hip replacement surgery for hip dysplasia, implanting acetabular component more proximally than anatomic acetabular center. Patients and methods: In 1997-2004 in the Red Cross Hospital, (later VUHSK CF) hospital 85 hip replacement surgeries for patients with I-IVº hip dysplasia were performed by implanting acetabular component more proximally from anatomic acetabular center. This method was used to perform surgeries to 83 patients (17 men – 18 hip joints, 66 women – 67 hip joints). Prior to the surgeries, the patients responded to the Harris questionnaire on the condition of their hip joints. An average response rate was 42.1 (29- 62) point. In February and May 2013 having regard to the Harris questionnaire and objective tests the late results of treatment were successfully evaluated for 44 (53.01%) patients. Results: The evaluation of the patients’ responses to the Harris questionnaire established the average of 61.7 (26-88) points. Conclusion: Based on our findings, more proximal positioning of the acetabular component from the anatomic acetabular center seeking a more anatomic position without lateral displacement is one of the surgical options for selected patients with hip dysplasia.

Development of Antifriction Materials Based on Polytetrafluoroethylene with Carbon Fibers and Tungsten Disulfide

2020 ◽  
Vol 992 ◽  
pp. 745-750
Author(s):  
A.P. Vasilev ◽  
T.S. Struchkova ◽  
A.G. Alekseev
Keyword(s):  
Wear Resistance ◽  
Polymer Composites ◽  
Carbon Fibers ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Relative Elongation ◽  
Tungsten Disulfide ◽  
Degree Of Crystallinity ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction

This paper presents the results from the investigation of effect the carbon fibers with tungsten disulfide on the mechanical and tribological properties of PTFE. Is carried out a comparison of mechanical and tribological properties of polymer composites PTFE-based with carbon fibers and PTFE with complex filler (carbon fibers with tungsten disulfide). It is shown that at a content of 8 wt.% CF+1 wt.% WS2 in PTFE, wear resistance increases significantly while maintaining the tensile strength, relative elongation at break and low coefficient of friction at the level of initial PTFE. The results of X-ray analysis and investigation of SEM supramolecular structure and friction surfaces of PTFE and polymer composites are presented. It is shown that the degree of crystallinity of polymer composites increases in comparison with the initial PTFE. The images of scanning electron microscope reveal that particles of tungsten disulfide concentrating on the friction surface is likely responsible to a reduction in the coefficient of friction and increase the wear resistance of PTFE-based polymer composites with complex fillers.

The Influence of Nano-Silica on the Wear Resistance of Ceramic – Polymer Composites Intended for Dental Fillings

2009 ◽  
Vol 151 ◽  
pp. 135-138
Author(s):  
Joanna Siejka-Kulczyk ◽  
Joanna Mystkowska ◽  
Małgorzata Lewandowska ◽  
Jan R. Dabrowski ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Wear Resistance ◽  
Polymer Composites ◽  
Coefficient Of Friction ◽  
Volume Fraction ◽  
Tooth Enamel ◽  
Nano Particles ◽  
Human Tooth ◽  
Nano Silica ◽  
The Coefficient Of Friction ◽  
Composite Samples

Ceramic – polymer composites based on acrylic (bis–GMA) and urethane – methacrylate (UM) resins with a 60 % total volume fraction of filler consisting of micro particles of glass and nano-particles of silica were fabricated. The nano-silica contents were: 0, 10, 20 vol. %. The composite samples were subjected to wear tests using an occlusion simulator tester which applies reciprocating movement and cyclic loading on the test material. This method of testing provides some similarity to the masticatory pattern occurring in the mouth during eating. The enamel of a human tooth was used as a counter-sample. The coefficient of friction was determined and the wear resistance of the composite samples containing the various nano-silica contents was established. In addition, the relative influence of the composite composition on the rate of wear of the human tooth enamel was estimated. The results of the study indicate that the addition of nano-silica significantly improves the wear resistance of the ceramic – polymer composites and reduces the wear of enamel. It was found that the addition of nano-silica has no influence on the coefficient of friction. It was also established that composites based on UM resin show better wear resistance than those based on a mixture of bis-GMA and TEGDMA resin.

THE INFLUENCE OF UNIAXIAL COMPRESSION ON THE FRICTION COEFFICIENT (POLYMER–STEEL PAIR), WEAR, AND HARDNESS IN SELECTED THERMOPLASTICS

Tribologia ◽  
2018 ◽  
Vol 279 (3) ◽  
pp. 77-82 ◽  
Author(s):  
Maciej KUJAWA
Keyword(s):  
High Pressure ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Uniaxial Compression ◽  
Elastic Deformation ◽  
Coefficient Of Friction ◽  
Internal Diameter ◽  
Tension And Compression ◽  
The Coefficient Of Friction ◽  
Harsh Conditions

Plastic plain bearings are deformed during assembly. According to one of the leading manufacturers of plastic sliding elements, the bushing’s internal diameter may be reduced by up to 2.5%. Moreover, plastic sliding elements are increasingly used in harsh conditions (e.g., under high pressure). However, there are no papers that describe the influence of deformation under compression on the tribological properties of plastics. Specimens made of PTFE, PA6, and PE-HD were deformed while conducting the current research, and this deformation was maintained during cooperation with steel. The results of microhardness, wear, and the coefficient of friction tests were compared to data gathered during tests of non-deformed specimens. During deformation under compression (e ≈ 6%), microhardness lowered by up to 30% (PTFE). A significant reduction of hardness (by up to 15%) was observed when strain was only 2%, and up to this value of strain, there is mainly elastic deformation in the polymer. Changes of the coefficient of friction values were insignificant. In terms of PTFE and PE-HD, during deformation under compression up to e ≈ 6% , the block scar volumes were 20% and 40% larger, respectively, than the non-deformed form of specimens. In terms of PA6, the change in block scar volume was insignificant. It may seem that tension and compression ought to cause totally different effects. However, the comparison of the current results and the results described in the previous paper exposes that these two different processes led to the same effects – reducing hardness and increasing wear. Deformation of plastic sliding components as an effect of assembly appears to be minor; however, it affects polymer microhardness and wear resistance.

scholarly journals Influence Of Lubricants On Wear Resistance Of Aluminum Alloy Strips Series 2XXX

2015 ◽  
Vol 60 (3) ◽  
pp. 1833-1838
Author(s):  
K. Żaba ◽  
P. Kita ◽  
M. Nowosielski ◽  
M. Kwiatkowski ◽  
M. Madej
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
2024 Aluminum Alloy ◽  
Aluminum Alloy 2024 ◽  
Materials Used ◽  
Oil Company ◽  
Selection Of

Abstract The article presents a properly planned and designed tests of the abrasive wear resistance 2024 aluminum alloy strips under friction conditions involving various lubricants. Test were focused on the selection of the best lubricant for use in industrial environment, especially for sheet metal forming. Three lubricants of the Orlen Oil Company and one used in the sheet metal forming industry, were selected for tests. Tests without the use of lubricant were performed for a comparison. The tester T-05 was used for testing resistance to wear. As the counter samples were used tool steel - NC6 and steel for hot working - WCL, which are typical materials used for tools for pressing. The results are presented in the form of the force friction, abrasion depth, weight loss and coefficient of friction depending on the lubricant used and the type of counter samples. The results allowed for predicting set lubricant-material for tools which can be applied to sheet metal made of aluminum alloy 2024.

scholarly journals Experimental and Analytical Investigations on Tribological Properties of PTFE/AP Composites

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4295
Author(s):  
Hai Wang ◽  
Annan Sun ◽  
Xiaowen Qi ◽  
Yu Dong ◽  
Bingli Fan
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Chemical Structure ◽  
Element Composition ◽  
Support Material ◽  
Test Conditions ◽  
Transfer Films ◽  
The Coefficient Of Friction

The tribological properties of polytetrafluoroethylene (PTFE)/AP (poly(para-phenyleneterephthalamide) (PPTA) pulp) composites under different test conditions (load: 2N, 10N; frequency: 1 Hz, 4 Hz; amplitude: 2 mm, 8 mm) were holistically evaluated. PTFE/AP composites with different AP mass ratios of 3%, 6%, and 12% as a skeleton support material were prepared. The coefficient of friction (COF) and wear rate were determined on a ball-on-disk tribometer. Furthermore, the morphology, element composition, and chemical structure of the transfer membrane were analyzed accordingly. The relationships between load, frequency, amplitude, and tribological properties were further investigated. According to the wear mechanism, AP enables effective improvement in the stiffness and wear resistance, which is also conducive to the formation of transfer films.

scholarly journals Effect of Bulk Current Density on Tribological Properties of Fe-W, Co-W and Ni-W Coatings

2015 ◽  
Author(s):  
S.A. Silkin ◽  
A.V. Gotelyak ◽  
N. Tsyntsaru ◽  
A.I. Dikusar ◽  
R. Kreivaitis ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Current Density ◽  
Dry Friction ◽  
Scratch Test ◽  
Tribological Behaviour ◽  
The Coefficient Of Friction ◽  
Current Densities ◽  
Scratch Tests ◽  
The Given

Evaluation of tribological behaviour of Fe-W, Ni-W and Co-W coatings produced by electrodeposition at various bulk current densities (BCD) was under investigation in the given study. BCD does not have essential effect on the microhardness and wear characteristics of Fe-W and Co-W coatings. But the scratch tests reveal the presence of such influence. These tests showed superior wear resistance for the coatings obtained at low BCD. It was found that BCD has influence on wear resistance of Ni-W coatings under dry friction conditions. The BCD also has an influence on the coefficient of friction of Fe-W and Ni-W coatings at dry friction conditions. However, such an effect is opposite to that, observed at the scratch test.

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