Surface Temperature Of Running Tires Using Infrared Scanning,
2015
The University Of Akron
Surface Temperature Of Running Tires Using Infrared Scanning, F. Conant, Joseph Walter
Dr. Joseph D. Walter
An infrared line scanning system has been used to measure surface temperatures of automobile tires under operating conditions. A designed experiment was employed to demonstrate statistically the individual and interaction effects on tire temperature profiles of changes in tire speed, inflation pressure, and wheel load. These effects are different at different radial positions on a given tire and are quite dependent on tire construction, as illustrated by application to bias, belted-bias, and radial tires of comparable sizes.
Centrifugal Effects In Inflated, Rotating Bias-Ply Tires,
2015
The University Of Akron
Centrifugal Effects In Inflated, Rotating Bias-Ply Tires, Joseph Walter
Dr. Joseph D. Walter
An equation is derived which governs the dynamic equilibrium contour taken by an inflated and rotating, but otherwise unloaded, bias-ply tire. This equation, which is in the form of a hyperelliptic integral, is based on the membrane theory of shells and the netting analysis of composite materials. Results are obtained for the meridional geom etry of a typical two-ply automobile tire, which are in reasonable agreement with ex perimental measurements. This integral, which describes the dynamic equilibrium contour of the tire, is then used to obtain an algebraic cord load formula. The formula shows how the cord tension at any …
Pneumatic Tire,
2015
The University Of Akron
Pneumatic Tire, Alan Neville Gent, Joseph D. Walter
Dr. Joseph D. Walter
For many years, tire engineers relied on the monograph, 'Mechanics of Pneumatic Tires', for detailed information about the principles of tire design and use. Published originally by the National Bureau of Standards, U.S. Department of Commerce, in 1971, and a later (1981) edition by the National Highway Traffic Safety Administration (NHTSA), U.S. Department of Transportation, it has long been out of print. No textbook or monograph of comparable range and depth has appeared since. While many chapters of the two editions contain authoritative reviews that are still relevant today, they were prepared in an era when bias ply and belted-bias …
Cord—Rubber Tire Composites: Theory And Applications,
2015
The University Of Akron
Cord—Rubber Tire Composites: Theory And Applications, Joseph Walter
Dr. Joseph D. Walter
The stiffness and strength behavior of the constituent cord and rubber components of the pneumatic tire have been studied in detail by investigators in the industry since the early days of tire production. For example, the effect of twist on the stress-strain properties of cotton tire cord and the reinforcing effect of carbon black on the modulus of natural rubber were well known phenomena many decades ago. Similarly, differences between the elastic and viscoelastic behavior of cord and rubber have been well documented since the 1940's. On the other hand, the material properties (specifically, the elastic constants) of the cord-rubber …
Radial Tire Cord-Rubber Composites,
2015
The University Of Akron
Radial Tire Cord-Rubber Composites, H. Patel, J. Turner, Joseph Walter
Dr. Joseph D. Walter
Experimental and theoretical results are presented in terms of the elements of the compliance matrix for the material properties which are needed to characterize a calendered ply of various cord-rubber composites commonly used in the body and belt of radial tires. It is shown that a single ply can be represented as a linear, elastic, homogeneous, orthotropic material to a level of accuracy sufficient for modeling inflated, but otherwise unloaded, radial tires. Cord load distributions in the body, belt, and turnup ply endings are predicted and plotted from the bead to the crown of inflated radial tires using principles of …
Interlaminar-Shear-Strain Measurements In Cord-Rubber Composites,
2015
The University Of Akron
Interlaminar-Shear-Strain Measurements In Cord-Rubber Composites, A. Lou, Joseph Walter
Dr. Joseph D. Walter
The present work is an experimental study using an X-ray technique to measure directly the internal distribution of interlaminar-shear deformations which occur during uniaxial extension of two-ply, cord-rubber, angle-ply laminates—both balanced and unbalanced. Significant interlaminar-shear strains were developed between the two generally orthotropic layers of one-inch-wide specimens, which decreased almost linearly from a maximum at the edges to zero at the center line. These measurements, and those as a function of cord angle, were in good agreement with predictions obtained from various theories of laminated shear-flexible composites.
A Tirecord Tension Transducer,
2015
The University Of Akron
A Tirecord Tension Transducer, Joseph Walter
Dr. Joseph D. Walter
A transducer is described which can directly measure the cord tension at any point in an arbitrarily loaded tire. Cord force data obtained at the crown and in the sidewall for a typical two-ply automobile tire are presented for: (1) the inflation problem, (2) the static deflection problem, and (3) the rolling tire. Agreement between theory and experiment is good for the inflation problem, which is the only case where a cord load formula exists to allow comparison.
Approximate Expressions For The Elastic Constants Of Cord-Rubber Laminates,
2015
The University Of Akron
Approximate Expressions For The Elastic Constants Of Cord-Rubber Laminates, Joseph Walter, H. Patel
Dr. Joseph D. Walter
The relatively simple equations given herein for the four independent elastic constants of a single ply of cord and rubber and for the three independent elastic constants of a cord-rubber angle-ply laminate can be used to assess with sufficient accuracy for many purposes the effect of changes in constituent material properties and/or ply geometry on the stiffness characteristics of unidirectional, filamentary composites used in pneumatic tires.
The Effect Of Cutting Blade Geometry And Material On Carbon Fiber Severing As Used In High-Volume Production Of Composites,
2015
The University of Western Ontario
The Effect Of Cutting Blade Geometry And Material On Carbon Fiber Severing As Used In High-Volume Production Of Composites, Michael Francis Anthony Adamovsky
Electronic Thesis and Dissertation Repository
Automotive manufacturers have started to actively look into weight savings options for mass production of vehicles that meet new government regulations. Falling prices of carbon fibers have made carbon fiber composites a promising material to be used. The study has focused on the fiber-severing unit incorporated in a high-volume composite production line in an attempt to better define the impact of blade geometry and material on the wear as experienced while cutting carbon fiber. A method to quantify the effect of usage on the cutting ability of a blade has been developed, as well as methods to measure blade wear. …
Investigation Of Synthesis And Processing Of Cellulose, Cellulose Acetate And Poly(Ethylene Oxide) Nanofibers Incorporating Anti-Cancer/Tumor Drug Cis-Diammineplatinum (Ii) Dichloride Using Electrospinning Techniques,
2015
Georgia Southern University
Investigation Of Synthesis And Processing Of Cellulose, Cellulose Acetate And Poly(Ethylene Oxide) Nanofibers Incorporating Anti-Cancer/Tumor Drug Cis-Diammineplatinum (Ii) Dichloride Using Electrospinning Techniques, Saheem Absar, Mujibur R. Khan, Kyle Edwards, Jeffrey Neumann
Department of Mechanical Engineering Faculty Publications
A model anti-cancer/tumor drug cis-diammineplatinum (II) dichloride (cisplatin) was loaded into micro- and nanofibers of cellulose, cellulose acetate (CA) and poly(ethylene oxide) (PEO), using various electrospinning techniques. Single-nozzle electrospinning was used to fabricate neat fibers of each category. Drug loading in cellulose fibers was performed using single-nozzle electrospinning. Encapsulation of cisplatin in CA and PEO-based fibers was performed using coaxial electrospinning. Morphological analysis of the fibers was performed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The various categories of fibers exhibited diverse morphological features depending on the material compositions and applied process parameters. The drug-loaded cellulose …
Isolation And Dissociation Of Immune Complexes From Pleural Effusions Of Lymphoma Patients,
2015
The University Of Akron
Isolation And Dissociation Of Immune Complexes From Pleural Effusions Of Lymphoma Patients, Geeta V. Patel, Mangesh N. Satam, Gopal Nadkarni
Dr. Gopal Nadkarni
Immune complexes (IC) isolated from pleural effusions of lymphomas with favorable and unfavorable prognoses were of IgG type. These IC were further dissociated by ion exchange chromatography using 8 M urea. The antibody was found to be a high molecular weight protein (1.5 x l0 s daltons) and reacted with antihuman IgG immunologically while a second peak obtained on ion exchange chromatography may be an antigen moiety with a molecular weight of 3.2 × 10 4 daltons as it reacted immunologically with the antibody. Strong cytoplasmic fluorescence was observed with various cell suspensions of lymphomas when reacted with the antibody …
Accelerating Technology Commercializationuniversity Of Akron (Ohio) Using The Nsf I-Corps Model,
2015
The University Of Akron
Accelerating Technology Commercializationuniversity Of Akron (Ohio) Using The Nsf I-Corps Model, Gopal Nadkarni, Elyse Ball, Daniel Hampu
Dr. Gopal Nadkarni
The paper explores the new technology commercialization model being followed at The University of Akron (UA).UA has implemented the National Science Foundation (NSF)Innovation ICorpsTMmodel since 2013. This paper describes how the NSF I-Corps model has changed the innovation culture at UA and allowed the academic faculty to explore the business potential of their intellectual property.Differences in implementation across several I-Corps Sites are explored. The lessons from UA's experience show that the I-Corps Sites program has been a resounding success and helped faculty and students to become more entrepreneurial in exploring the commercial value and demand drivers of technologies invented at …
Thermal Activation In Atomic Friction: Revisiting The Theoretical Analysis,
2015
The University of Akron, Main Campus
Thermal Activation In Atomic Friction: Revisiting The Theoretical Analysis, Yalin Dong, D. Perez, H. Gao, A. Martini
Dr. Yalin Dong
The effect of thermal activation on atomic-scale friction is often described in the framework of the Prandtl–Tomlinson model. Accurate use of this model relies on parameters that describe the shape of the corrugation potential β and the transition attempt frequency f0. We show that the commonly used form of β for a sinusoidal corrugation potential can lead to underestimation of friction, and that the attempt frequency is not, as is usually assumed, a constant value, but rather varies as the energy landscape evolves. We partially resolve these issues by demonstrating that numerical results can be captured by a model with …
Atomic Friction Modulation On The Reconstructed Au(111) Surface,
2015
The University of Akron, Main Campus
Atomic Friction Modulation On The Reconstructed Au(111) Surface, Qunyang Li, Yalin Dong, Ashlie Martini, Robert Carpick
Dr. Yalin Dong
Friction between a nanoscale tip and a reconstructed Au(111) surface is investigated both by atomic force microscopy (AFM) and molecular statics calculations. Lateral force AFM images exhibit atomic lattice stick–slip behavior with a superstructure corresponding to the herringbone reconstruction pattern. However, the superstructure contrast is not primarily due to variations in the local frictional dissipation (which corresponds to the local width of the friction loop). Rather, the contrast occurs primarily because the local centerline position of the friction loop is periodically shifted from its usual value of zero. Qualitatively, similar behavior is reproduced in atomistic simulations of an AFM tip …
Atomic Roughness Enhanced Friction On Hydrogenated Graphene,
2015
The University of Akron, Main Campus
Atomic Roughness Enhanced Friction On Hydrogenated Graphene, Yalin Dong, Xiawa Wu, Ashlie Martini
Dr. Yalin Dong
Atomic friction on hydrogenated graphene is investigated using molecular dynamics simulations. Hydrogenation is found to increase friction significantly, and the atomic-level information provided by the simulations reveals that atomic roughness induced by hydrogenation is the primary cause of the friction enhancement. Other proposed mechanisms, specifically adhesion and rigidity, are excluded based on the simulation results and analyses performed using the Prandtl–Tomlinson model. In addition, it is found that friction does not monotonically increase with hydrogen coverage on the graphene surface; instead, a maximum friction is observed at a hydrogen coverage between 5 and 10%.
Analytical Models For Atomic Friction,
2015
The University of Akron, Main Campus
Analytical Models For Atomic Friction, Yalin Dong, Ajay Vadakkepatt, Ashlie Martini
Dr. Yalin Dong
In this methods article, we describe application of Prandtl–Tomlinson models and their extensions to interpret dry atomic-scale friction. The goal is to provide a practical overview of how to use these models to study frictional phenomena. We begin with the fundamental equations and build on them step-by-step—from the simple quasistatic one-spring, one-mass model for predicting transitions between friction regimes to the two-dimensional and multi-atom models for describing the effect of contact area. The intention is to bridge the gap between theoretical analysis, numerical implementation, and predicted physical phenomena. In the process, we provide an introductory manual with example computer programs …
Reinterpretation Of Velocity-Dependent Atomic Friction: Influence Of The Inherent Instrumental Noise In Friction Force Microscopes,
2015
The University of Akron, Main Campus
Reinterpretation Of Velocity-Dependent Atomic Friction: Influence Of The Inherent Instrumental Noise In Friction Force Microscopes, Yalin Dong, Hongyu Gao, Ashlie Martini, Philip Egberts
Dr. Yalin Dong
We have applied both the master equation method and harmonic transition state theory to interpret the velocity-dependent friction behavior observed in atomic friction experiments. To understand the discrepancy between attempt frequencies measured in atomic force microscopy experiments and those estimated by theoretical models, both thermal noise and instrumental noise are introduced into the model. It is found that the experimentally observed low attempt frequency and the transition point at low velocity regimes can be interpreted in terms of the instrumental noise inherent in atomic force microscopy. In contrast to previous models, this model also predicts (1) the existence of a …
Friction, Slip And Structural Inhomogeneity Of The Buried Interface,
2015
The University of Akron, Main Campus
Friction, Slip And Structural Inhomogeneity Of The Buried Interface, Yalin Dong, Q. Li, A. Martini
Dr. Yalin Dong
An atomistic model of metallic contacts using realistic interatomic potentials is used to study the connection between friction, slip and the structure of the buried interface. Incommensurability induced by misalignment and lattice mismatch is modeled with contact sizes that are large enough to observe superstructures formed by the relative orientations of the surfaces. The periodicity of the superstructures is quantitatively related to inhomogeneous shear stress distributions in the contact area, and a reduced order model is used to clarify the connection between friction and structural inhomogeneity. Finally, the movement of atoms is evaluated before, during and after slip in both …
Suppression Of Atomic Friction Under Cryogenic Conditions: The Role Of Athermal Instability In Afm Measurements,
2015
The University of Akron, Main Campus
Suppression Of Atomic Friction Under Cryogenic Conditions: The Role Of Athermal Instability In Afm Measurements, Yalin Dong, H. Gao, A. Martini
Dr. Yalin Dong
A theoretical investigation of the behavior of atomic friction at low temperatures is performed using a master equation method with a two-mass, two-spring Prandtl-Tomlinson model of an atomic force microscope experiment. A novel approach is taken in which two distinct instability mechanisms are introduced into the model: thermal activation is described by transition state theory with a prefactor associated with the frequency of the tip apex, and athermal instability is introduced by an Arrhenius-like equation with a prefactor associated with the characteristic frequency of the cantilever. Thermal instability causes the often reported decrease of friction with temperature followed by a …
Variation Of Friction With Number Of Graphene Layers,
2015
The University of Akron, Main Campus
Variation Of Friction With Number Of Graphene Layers, Zhijiang Ye, Chun Tang, Yalin Dong, Ashlie Martini
Dr. Yalin Dong
The article focuses on a research that explains the variation of friction in lubricated system by using graphene layers. It mentions that graphite is widely used in lubricated system as it has weak interlayer interaction strength that cause low friction. It reflects on the use of friction force microscopy (FFM) to study the nanostructure of graphene and mentions that graphene explains the phenomenon of wrinkle formation in lubricants and impact of layers or sheet size on friction.
