Open Access. Powered by Scholars. Published by Universities.®

Tribology Commons

Open Access. Powered by Scholars. Published by Universities.®

80 Full-Text Articles 138 Authors 29,754 Downloads 20 Institutions

All Articles in Tribology

Faceted Search

80 full-text articles. Page 2 of 4.

Application Of Ultrasound In The Measurement Of Lubricant Fluid Film Thickness In The Piston-Cylinder Interface Of An Axial Piston Pump, Dhruv Subramaniam, Dan Mizell, Monika Ivantysynova 2015 Purdue University

Application Of Ultrasound In The Measurement Of Lubricant Fluid Film Thickness In The Piston-Cylinder Interface Of An Axial Piston Pump, Dhruv Subramaniam, Dan Mizell, Monika Ivantysynova

The Summer Undergraduate Research Fellowship (SURF) Symposium

In this paper a feasibility study has been conducted to determine a technique for the measurement of lubricant fluid film thickness in the piston-cylinder interface of an axial piston pump. The thickness of the lubricant film has a significant impact on the efficiency of the piston pump yet it still remains an uncertainty. If the lubricant film is too thin then friction will cause excessive damage resulting in deformation of interacting surfaces resulting in further uncertainty in thickness measurement. If the lubricant film is too thick then there is excessive leakage which will compromise the efficiency of the system. Acoustic ...


Characterization Of Nano-Porous Si-Cu Composites To Enhance Lubricant Retention Impacting The Tribological Properties Of Sliding Surfaces, Julius Sheldon Morehead 2015 University of Arkansas, Fayetteville

Characterization Of Nano-Porous Si-Cu Composites To Enhance Lubricant Retention Impacting The Tribological Properties Of Sliding Surfaces, Julius Sheldon Morehead

Theses and Dissertations

As the expectations for modern machinery's tribological and thermal performances continue to rise, the retention of lubricant on the contact surfaces of their sliding components becomes an increasingly important issue. Friction and wear cause heat-related failures which lead to catastrophic damage to machinery. Evaporation of a lubricant's volatile constituents as well as lubricant migration leads not only to a reduction in lubricant quantity but also in its quality, thus facilitating component failures. In order to enhance component reliability, the surface should incorporate features that actively retain lubricants. The unique properties of nano-porous topographies such as their high surface ...


Skin Tribology Phenomena Associated With Reading Braille Print: The Influence Of Cell Patterns And Skin Behavior On Coefficient Of Friction, Matthew A. Darden, Christian J. Schwartz 2015 Iowa State University

Skin Tribology Phenomena Associated With Reading Braille Print: The Influence Of Cell Patterns And Skin Behavior On Coefficient Of Friction, Matthew A. Darden, Christian J. Schwartz

Mechanical Engineering Publications

Efficient transmission of tactile information is vital for individuals who rely on their sense of touch to interact with and navigate their surroundings, including visually impaired persons. Somatosensory phenomena have been investigated with respect to surface topologies and neuron sensitivities in the skin, but there is little knowledge of the specific skin tribology when reading tactual-coded information such as braille. Braille is a tactual code that employs raised dome-shaped dots in six-position cells (2 columns by 3 rows per cell), with various dot patterns representing individual text characters, punctuation or mathematical operators. Due to the hypothesized significance of friction on ...


Magnetic Bearings For Non-Destructive Health Monitoring Of Rotating Machinery Supported In Conventional Bearings, M. Kasarda, D, Quinn, T. Bash, D. Inman, R. Kirk, Jerzy Sawicki 2015 Virginia Tech

Magnetic Bearings For Non-Destructive Health Monitoring Of Rotating Machinery Supported In Conventional Bearings, M. Kasarda, D, Quinn, T. Bash, D. Inman, R. Kirk, Jerzy Sawicki

Dr. D Dane Quinn

This paper describes initial results from a project expanding the field of rotor health monitoring by using Active Magnetic Bearings (AMBs) as actuators for applying a variety of known force inputs to a spinning rotor in order to monitor and evaluate response signals resulting from these inputs on-line. Similar to modal analysis and other nondestructive evaluation (NDE) techniques which apply input signals to static structures in order to monitor responses; this approach allows for the measurement of both input and output response in a rotating system for evaluation. However, unlike these techniques, the new procedure allows for multiple forms of ...


In-Vivo Corrosion And Fretting Of Modular Ti-6al-4v/Co-Cr-Mo Hip Prostheses: The Influence Of Microstructure And Design Parameters, Jose Luis Gonzalez Jr 2015 Florida International University

In-Vivo Corrosion And Fretting Of Modular Ti-6al-4v/Co-Cr-Mo Hip Prostheses: The Influence Of Microstructure And Design Parameters, Jose Luis Gonzalez Jr

FIU Electronic Theses and Dissertations

The purpose of this study was to evaluate the incidence of corrosion and fretting in 48 retrieved titanium-6aluminum-4vanadium and/or cobalt-chromium-molybdenum modular total hip prosthesis with respect to alloy material microstructure and design parameters. The results revealed vastly different performance results for the wide array of microstructures examined. Severe corrosion/fretting was seen in 100% of as-cast, 24% of low carbon wrought, 9% of high carbon wrought and 5% of solution heat treated cobalt-chrome. Severe corrosion/fretting was observed in 60% of Ti-6Al-4V components. Design features which allow for fluid entry and stagnation, amplification of contact pressure and/or increased ...


A Comparison Between Graphene And Ws2 As Solid Lubricant Additives To Aluminum For Automobile Applications, Sara Rengifo 2015 Florida International University

A Comparison Between Graphene And Ws2 As Solid Lubricant Additives To Aluminum For Automobile Applications, Sara Rengifo

FIU Electronic Theses and Dissertations

The purpose of this thesis was to compare graphene nanoplatelets (GNP) and WS2 as solid lubricant additives to aluminum in order to reduce friction and wear. The central hypothesis of this work relied on lubricating properties of 2D materials, which consist layers that slip under a shear force.

Two aluminum composites were made (Al-2 vol.% GNP and Al-2 vol.% WS2) by spark plasma sintering. Tribological properties were evaluated by ball-on-disk wear tests at room temperature (RT) and 200°C.

WS2 not only presented the lowest COF (0.66) but also improved the wear resistance of aluminum by ...


Assessment Of The Wear Effects Of Alumina-Nanofluids On Heat-Exchanger Materials, FNU Aktaruzzaman 2015 Georgia Southern University

Assessment Of The Wear Effects Of Alumina-Nanofluids On Heat-Exchanger Materials, Fnu Aktaruzzaman

Electronic Theses and Dissertations

Nanofluids are nano-size-powder suspensions in liquids that are mainly studied for their abnormal thermal transport properties, and hence as enhanced alternatives to ordinary cooling fluids. The tribological effects of nanofluids are, however, largely unknown, in particular their likely wear and/or erosion effects, because of their interaction with cooling-system (heat-exchanger) materials. The thesis presents research to establish methodologies for testing and evaluating surface-change by nanofluid impact. The work is presented on development of novel test rigs and testing methodologies, and on the use of typical surface analysis tools for assessment of wear and erosion that may be produced by nanofluids ...


Investigation Of The Effect Of The Normal Load On The Incidence Of Friction Blisters In A Skin-Simulant Model, Geetha Chimata, Christian J. Schwartz 2015 Iowa State University

Investigation Of The Effect Of The Normal Load On The Incidence Of Friction Blisters In A Skin-Simulant Model, Geetha Chimata, Christian J. Schwartz

Mechanical Engineering Publications

A laminar skin simulant was constructed to study the incidence of friction blisters. The skin simulant consists of a thin polyurethane top layer and textured gum foam rubber bottom layer adhered to an acrylic-backing plate to emulate the layered structure of the human skin. Friction blisters were produced on the skin simulant by using a dual-axis tribometer. The effect of the applied normal load on the number of cycles required to produce a blister was investigated. The skin simulant was also analyzed as an adhesive-bonded laminar composite to determine the relationship between the applied normal load and the number of ...


Wear Resistant Polydopamine/Ptfe Nanoparticle Composite Coating For Dry Lubrication Applications, Samuel George Beckford 2014 University of Arkansas, Fayetteville

Wear Resistant Polydopamine/Ptfe Nanoparticle Composite Coating For Dry Lubrication Applications, Samuel George Beckford

Theses and Dissertations

This dissertation presents an investigation into the effect of nanoparticle fillers and a polydopamine adhesive primer on the tribological performance of thin PTFE films. The principal objective of this investigation was to reduce wear in PTFE films, an issue which precludes the use of PTFE films in tribological applications requiring high durability. The friction and wear of the composite films were evaluated using a ball-on-flat configuration in linear reciprocating motion. It was found that the use of a polydopamine adhesive primer reduces the wear of PTFE films more than 600 times. X-ray photoelectron spectroscopy (XPS) results show that a tenacious ...


Surface Modification Of Aluminum Alloys By Plasma Electrolytic Oxidation, Vahid Dehnavi 2014 The University of Western Ontario

Surface Modification Of Aluminum Alloys By Plasma Electrolytic Oxidation, Vahid Dehnavi

Electronic Thesis and Dissertation Repository

Plasma Electrolytic Oxidation (PEO) is a surface treatment for the production of ceramic oxide coatings with great properties, such as high wear and corrosion resistance, on metal substrates, particularly aluminum and magnesium alloys. Formation of PEO coatings involves complex processes and mechanisms that are difficult to study. Currently, the PEO process is in a transition phase from research to commercial application, with a primary focus on the corrosion and wear protection of light alloys, and has recently generated interest as a promising surface treatment for biomedical applications.

To justify the industrial application of PEO, a more systematic and in-depth study ...


Modeling Of Mixed Friction Interactions Occurring In Axial Piston Pumps, Andrew C. Adelsperger, Lizhi Shang, Dan Mizell, Monika Ivantysynova 2014 Purdue University

Modeling Of Mixed Friction Interactions Occurring In Axial Piston Pumps, Andrew C. Adelsperger, Lizhi Shang, Dan Mizell, Monika Ivantysynova

The Summer Undergraduate Research Fellowship (SURF) Symposium

Axial piston pumps are integral to a variety of hydraulic systems due to their versatility and reliability, but most attempts to model them for design purposes have failed. However, software which fully models the fluid structures within these pumps, such as the FSTI gap design program, has improved significantly. Unfortunately, current discrepancies between simulated and measured friction forces on the cylinder due to the fluid drag and piston movement need to be eliminated so that more accurate simulation of these pumps in operation is possible. Friction measurements and FSTI simulation outputs were analyzed with MATLAB filters and graphs, resulting in ...


Micropillar Sequence Designs For Fundamental Inertial Flow Transformations, Daniel Stoecklein, Chueh-Yu Wu, Keegan Owsley, Yu Xie, Dino Di Carlo, Baskar Ganapathysubramanian 2014 Iowa State University

Micropillar Sequence Designs For Fundamental Inertial Flow Transformations, Daniel Stoecklein, Chueh-Yu Wu, Keegan Owsley, Yu Xie, Dino Di Carlo, Baskar Ganapathysubramanian

Mechanical Engineering Publications

The ability to control the shape of a flow in a passive microfluidic device enables potential applications in chemical reaction control, particle separation, and complex material fabrication. Recent work has demonstrated the concept of sculpting fluid streams in a microchannel using a set of pillars or other structures that individually deform a flow in a predictable pre-computed manner. These individual pillars are then placed in a defined sequence within the channel to yield the composition of the individual flow deformations – and ultimately complex user-defined flow shapes. In this way, an elegant mathematical operation can yield the final flow shape for ...


Peek Wear Test System, Michael Brown, Mason Chellemi, Allian Roman 2014 California Polytechnic State University - San Luis Obispo

Peek Wear Test System, Michael Brown, Mason Chellemi, Allian Roman

Mechanical Engineering

The wear characteristics of PEEK carbon fiber composites are not well understood in comparison to high strength materials in common use such as steel, aluminum, and carbon fiber epoxy. This lack of understanding limits the applications in which the superior strength to weight ratio and stiffness of PEEK carbon fiber composites may be utilized with confidence to situations in which there are no significant bearing surface interactions between nearby components. The objective of this project was to design, build, and test a machine that is capable of evaluating the behavior of PEEK carbon fiber composites in a long term, high ...


Prediction Of Tribological Behavior Of Candidate Materials For Rotor Seals, John W. Franzino, Will F. Michul 2014 California Polytechnic State University - San Luis Obispo

Prediction Of Tribological Behavior Of Candidate Materials For Rotor Seals, John W. Franzino, Will F. Michul

Materials Engineering

To reduce high costs associated with manufacturing and testing materials for rotor seals, a procedure needs to be developed to quickly and accurately test candidate materials as they are released. The test should reduce the amount of fabrication required and model working conditions in order to accurately assess the tribological behavior of candidate materials. A possible solution was examined that utilized a rig meant to model operational stresses and wear. Compression modulus data was then taken in order to quantify the accumulation of damage due to microcracking, the primary mode of failure, through a damage index parameter. Testing results concluded ...


Phase Transformation In Monolayer Molybdenum Disulphide With And Without Defects Under Tension Predicted By Atomistic Simulations, Khanh Quoc Dang 2014 University of Arkansas, Fayetteville

Phase Transformation In Monolayer Molybdenum Disulphide With And Without Defects Under Tension Predicted By Atomistic Simulations, Khanh Quoc Dang

Theses and Dissertations

In addition to its use as a solid lubricant, molybdenum disulphide (MoS2) has gained recent attention as a possible substitute for silicon as it is increasingly difficult to keep shrinking down electronic devices made of silicon, the conventional electronic material. When thinned down to atomic thickness, monolayer MoS2 possesses very unique and promising electronic and electrical properties. Unlike electronic and electrical properties, knowledge of the mechanical properties and role of structural defects on these properties of monolayer MoS2 is unexplored. For this thesis, the two main objectives are (1) to gain insight about the failure mechanism of monolayer MoS2 by ...


Nanofragmentation Of Ferroelectric Domains During Polarization Fatigue, H.Z. Guo, Xiaoming Liu, Jürgen Rödel, Xiaoli Tan 2014 Iowa State University

Nanofragmentation Of Ferroelectric Domains During Polarization Fatigue, H.Z. Guo, Xiaoming Liu, Jürgen Rödel, Xiaoli Tan

Materials Science and Engineering Publications

The microscopic mechanism for polarization fatigue in ferroelectric oxides has remained an open issue for several decades in the condensed matter physics community. Even though numerous models are proposed, a consensus has yet to be reached. Since polarization reversal is realized through ferroelectric domains, their behavior during electric cycling is critical to elucidating the microstructural origin for the deteriorating performance. In this study, electric field in situ transmission electron microscopy is employed for the first time to reveal the domain dynamics at the nanoscale through more than 103 cycles of bipolar fields. A novel mechanism of domainfragmentation is directly visualized ...


Trampoline And Bungee Fatigue-Test Machine, Andy Brock, Christopher D'Elia, Ryan Murphy 2013 California Polytechnic State University - San Luis Obispo

Trampoline And Bungee Fatigue-Test Machine, Andy Brock, Christopher D'Elia, Ryan Murphy

Mechanical Engineering

JumpSport, a Saratoga based recreational and fitness trampoline company, sponsored this senior project team towards the development of a fatigue-testing machine. The goal of this project was to iterate the previous machine JumpSport used for bungee cord, spring, and trampoline fatigue testing. Since minimal study had been conducted on these specific bungee cords, the fixture was designed to confirm the theoretical correlations for rubber and perform the final tests according to a strict protocol. Operating with a specific test protocol in mind will allow the data from multiple tests to be combined and analyzed statistically. With a design concept in ...


Experimental And Theoretical Investigations Of Lube Oil Performance And Engine Friction, William Fredrick Rohr 2013 University of Tennessee, Knoxville

Experimental And Theoretical Investigations Of Lube Oil Performance And Engine Friction, William Fredrick Rohr

Doctoral Dissertations

The feasibility of using a motored small, single-cylinder 517 cc Hatz 1D50 diesel engine to evaluate lube oil performance and engine friction at conditions typical for a fired engine is investigated in the present study. In addition a commercial engine modeling software, AVL Excite Power Unit, is used to predict the effects of lube oil formulations on the engine friction of the same engine. The motored engine can be operated with and without compression and with and without the engine oil pump. Lube oil performance is evaluated for 19 different lube oils by using either instantaneous motoring torque (motoring torque ...


Surface Layer Plastic Deformation As A Mechanism For Uhmwpe Wear, And Its Role In Debris Size., Kevin G. Plumlee, Christian J. Schwartz 2013 Oklahoma Christian University

Surface Layer Plastic Deformation As A Mechanism For Uhmwpe Wear, And Its Role In Debris Size., Kevin G. Plumlee, Christian J. Schwartz

Mechanical Engineering Publications

Ultra-high molecular weight polyethylene (UHMWPE) remains the primary bearing material for use in artificial joints, but the longevity of these implants is still hindered by an osteolytic immune system response initiated by sub-micron sized wear debris released from the UHMWPE bulk component. Studies have shown that the severity of the immune system response is linked to particle size. Current treatments for reducing this effect focus on reducing the total volume of wear, but do not directly address particle size due to a limited understanding of the mechanisms involved in producing such small debris. Directly observing these mechanisms is inherently challenging ...


Influence Of Linear Reciprocating And Multi-Directional Sliding On Peek Wear Performance And Transfer Film Formation, Kevin A. Laux, Christian J. Schwartz 2013 Texas A&M University

Influence Of Linear Reciprocating And Multi-Directional Sliding On Peek Wear Performance And Transfer Film Formation, Kevin A. Laux, Christian J. Schwartz

Mechanical Engineering Publications

Because of their light weight, chemical resistance, and self-lubricating properties, polymers are used in applications ranging from biomedical to aerospace. Some polymers exhibit significant differences in wear resistancebased on whether they are in unidirectional or multidirectional sliding. Shear induced polymer chain orientation is believed to be responsible for this behavior. Polyetheretherketone (PEEK) has excellent wear resistance, but its multidirectional sliding behavior has not been thoroughly investigated. A factorial multidirectional pin-on-plate wear study of PEEK was conducted with a focus on molecular weight and sliding path directionality. These factors were studied for their correlation to over all wear performance. Additionally ...


Digital Commons powered by bepress