Browse
Submit Data
Databases
API
Help

Dataset Information

24 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Onset of frictional sliding of rubber-glass contact under dry and lubricated conditions.

ABSTRACT: Rubber friction is critical in many applications ranging from automotive tyres to cylinder seals. The process where a static rubber sample transitions to frictional sliding is particularly poorly understood. The experimental and simulation results in this paper show a completely different detachment process from the static situation to sliding motion under dry and lubricated conditions. The results underline the contribution of the rubber bulk properties to the static friction force. In fact, simple Amontons' law is sufficient as a local friction law to produce the correct detachment pattern when the rubber material and loading conditions are modelled properly. Simulations show that micro-sliding due to vertical loading can release initial shear stresses and lead to a high static/dynamic friction coefficient ratio, as observed in the measurements.

SUBMITTER: Tuononen AJ

PROVIDER: S-EPMC4904280 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Onset of frictional sliding of rubber-glass contact under dry and lubricated conditions.

Tuononen Ari J AJ

Scientific reports 20160613

Rubber friction is critical in many applications ranging from automotive tyres to cylinder seals. The process where a static rubber sample transitions to frictional sliding is particularly poorly understood. The experimental and simulation results in this paper show a completely different detachment process from the static situation to sliding motion under dry and lubricated conditions. The results underline the contribution of the rubber bulk properties to the static friction force. In fact, si ...[more]

PMID: 27291939

Similar Datasets

Comparison of Frictional Properties of CVD-Grown MoS₂ and Graphene Films under Dry Sliding Conditions.

Project description:In the present study, dry friction and wear properties of atomically thin CVD-grown graphene and MoS₂ films on SiO₂/Si substrates were compared at low (72 MPa) and high (378 MPa) contact pressures. Analysis of atomic force microscopy images of these films verified that the MoS₂ films, which were directly grown on the SiO₂/Si substrates, had clean surfaces and made conformal contacts with the substrates. In contrast, the graphene film showed many contaminants on its surface and was loosely bonded with its SiO₂/Si substrate due to its wet transfer from a Cu foil to the substrate. The MoS₂ film exhibited friction and wear properties superior to those of the graphene film both at low and high contact pressures. We found that the clean sliding surface and strong bonding with SiO₂/Si were the main causes of the superiority of the MoS₂ film compared to the graphene film. Mild wear occurred in a layer-by-layer fashion at low contact pressure for the MoS₂ film. At high contact pressure, severe wear occurred due to failure at the boundary between the MoS₂ films and the underlying substrates. At both contact pressures, friction did not increase immediately after the removal of the MoS₂ film from the SiO₂/Si substrate because the film transferred onto the counter sliding surface and served as a lubricant.

| S-EPMC6410133 | biostudies-literature

Autonomous nanorobots with powerful thrust under dry solid-contact conditions by photothermal shock.

Project description:Nanorobotic motion on solid substrates is greatly hindered by strong nanofriction, and powerful nanomotors‒the core components for nanorobotic motion‒are still lacking. Optical actuation addresses power and motion control issues simultaneously, while conventional technologies with small thrust usually apply to fluid environments. Here, we demonstrate micronewton-thrust nanomotors that enable the autonomous nanorobots working like conventional robots with precise motion control on dry surfaces by a photothermal-shock technique. We build a pulsed laser-based actuation and trapping platform, termed photothermal-shock tweezers, for general motion control of metallic nanomaterials and assembled nanorobots with nanoscale precision. The thrust-to-weight ratios up to 107 enable nanomotors output forces to interact with external micro/nano-objects. Leveraging machine vision and deep learning technologies, we assemble the nanomotors into autonomous nanorobots with complex structures, and demonstrate multi-degree-of-freedom motion and sophisticated functions. Our photothermal shock-actuation concept fundamentally addresses the nanotribology challenges and expands the nanorobotic horizon from fluids to dry solid surfaces.

| S-EPMC10674020 | biostudies-literature

Superlubricity of Graphite Sliding against Graphene Nanoflake under Ultrahigh Contact Pressure.

Project description:Superlubricity of graphite sliding against graphene can be easily attained at the nanoscale when it forms the incommensurate contact under a low contact pressure. However, the achievement of superlubricity under an ultrahigh contact pressure (>1 GPa), which has more applications in the lubrication of micromachine and nanomachine, remains unclear. Here, this problem is addressed and the robust superlubricity of graphite is obtained under ultrahigh contact pressures of up to 2.52 GPa, by the formation of transferred graphene nanoflakes on a silicon tip. The friction coefficient becomes as low as 0.0003, a state that is attributed to the extremely low shear strength of the graphene/graphite interface in the incommensurate contact. When the pressure exceeds some threshold, the superlubricity state collapses suddenly with the friction coefficient increasing ≈10 times. The failure of superlubricity originates from the delamination of the topmost graphene layers on graphite under ultrahigh contact pressures, which requires the tip to provide additional exfoliation energies during the sliding process. The results demonstrate that the superlubricity of graphite sliding against graphene can exist stably under ultrahigh contact pressure, which would appear to accelerate its application in nanoscale lubrication.

| S-EPMC6247022 | biostudies-literature

Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores.

Project description:When two macroscopic objects touch, the real contact typically consists of multiple surface asperities that are deformed under the pressure that holds the objects together. Application of a shear force makes the objects slide along each other, breaking the initial contacts. To investigate how the microscopic shear force at the asperity level evolves during the transition from static to dynamic friction, we apply a fluorogenic mechanophore to visualize and quantify the local interfacial shear force. When a contact is broken, the shear force is released and the molecules return to their dark state, allowing us to dynamically observe the evolution of the shear force at the sliding contacts. We find that the macroscopic coefficient of friction describes the microscopic friction well, and that slip propagates from the edge toward the center of the macroscopic contact area before sliding occurs. This allows for a local understanding of how surfaces start to slide.

| S-EPMC9531245 | biostudies-literature

Glass Chemistry to Analyze Human Cells under Adverse Conditions.

Project description:Emerging point-of-care diagnostic tests capable of analyzing whole mammalian cells often rely on the attachment of harvested cells to glass surfaces for subsequent molecular characterization. We set out to develop and optimize a kit for the diagnosis of lymphoma in low- and middle-income countries where access to advanced healthcare testing is often absent or prone to error. Here, we optimized a process for the lyophilization of neutravidin-coated glass and cocktails of antibodies relevant to lymphoma diagnosis to establish long-term stability of reagents required for point-of-care cell capture technology. Lyophilized glass slides showed no decline in their performance compared to freshly prepared neutravidin glass and preserved capture efficiency for 5 weeks under easily attainable storage conditions. We demonstrate the successful performance of the low-cost, lyophilized kit in a cell capture assay to enable true point-of-care analyses under adverse conditions. We anticipate that the strategy can be expanded to other cancer cell types or cell-derived vesicle analysis.

| S-EPMC6682085 | biostudies-literature

Tribological Properties of Water-lubricated Rubber Materials after Modification by MoS<sub>2</sub> Nanoparticles.

Project description:Frictional vibration and noise caused by water-lubricated rubber stern tube bearings, which are generated under extreme conditions, severely threaten underwater vehicles' survivability and concealment performance. This study investigates the effect of flaky and spherical MoS2 nanoparticles on tribological properties and damping capacity of water-lubricated rubber materials, with the aim of decreasing frictional noise. A CBZ-1 tribo-tester was used to conduct the sliding tests between rubber ring-discs and ZCuSn10Zn2 ring-discs with water lubrication. These materials' typical mechanical properties were analysed and compared. Coefficients of friction (COFs), wear rates, and surface morphologies were evaluated. Frictional noise and critical velocities of generating friction vibration were examined to corroborate above analysis. Results showed that spherical MoS2 nanoparticles enhanced rubber material's mechanical and tribological properties and, in turn, reduced the friction noise and critical velocity. Flaky MoS2 nanoparticles reduced COF but did not enhance their mechanical properties, i.e., the damping capacity, wear resistance property; thus, these nanoparticles did not reduce the critical velocity obviously, even though increased the frictional noise at high load. The knowledge gained in the present work will be useful for optimizing friction pairs under extreme conditions to decrease frictional noise of water-lubricated rubber stern tube bearings.

| S-EPMC5054368 | biostudies-literature

Durability of Lubricated Icephobic Coatings under Various Environmental Stresses.

Project description:Icephobic coatings interest various industries facing icing problems. However, their durability represents a current limitation in real applications. Therefore, understanding the degradation of coatings under various environmental stresses is necessary for further coating development. Here, lubricated icephobic coatings were fabricated using a flame spray method with hybrid feedstock injection. Low-density polyethylene represented the main coating component. Two additives, namely fully hydrogenated cottonseed oil and paraffinic wax, were added to the coating structure to enhance coating icephobicity. Coating properties were characterised, including topography, surface roughness, thermal properties, wettability, and icephobicity. Moreover, their performance was investigated under various environmental stresses, such as repeated icing/deicing cycles, immersion in corrosive media, and exposure to ultraviolet (UV) irradiation. According to the results, all coatings exhibited medium-low ice adhesion, with slightly more stable icephobic behaviour for cottonseed oil-based coatings over the icing/deicing cycles. Surface roughness slightly increased, and wetting performances decreased after the cyclic tests, but chemical changes were not revealed. Moreover, coatings demonstrated good chemical resistance in selected corrosive media, with better performance for paraffin-based coatings. However, a slight decrease in hydrophobicity was detected due to surface structural changes. Finally, paraffin-based coatings showed better resistance under UV irradiation based on carbonyl index and colour change measurements.

| S-EPMC8779144 | biostudies-literature

Fatigue-Induced Surface Modification of Zr-Based Metallic Glass under Environmental Conditions.

Project description:Metallic glass (MG), an intrinsic heterogeneous structure at the atomic scale, is one of the promising engineering materials with intriguing physical properties. MG often suffers from the fatigue issue caused by the repetitive mechanical loading, but it is still elusive how the local heterogeneity evolves and affects the macroscale fatigue and deformation against bulky external stress. In this study, we investigate the fatigue effect in Zr-Cu-Al ribbon using a bending fatigue method. We used scanning probe microscopy (SPM) in parallel with X-ray diffraction and X-ray photoelectron spectroscopy to figure out the loading effect on the local heterogeneities. The spatially resolved SPM images show that there is a local fluctuation of mechanical and electrical properties on the fatigued side along with morphological deformation compared to the unloaded side. Approaching the broken edge where the fatigue failure occurs, the decaying tendency is not only more dominant but also accelerated by surface oxidation of the fatigued regions. Our study provides a useful guideline on how to monitor structural changes of MGs under fatigue conditions in service and will open a door toward commercialization of high-performance structural engineering materials.

| S-EPMC9670298 | biostudies-literature

The onset of the frictional motion of dissimilar materials.

Project description:Frictional motion between contacting bodies is governed by propagating rupture fronts that are essentially earthquakes. These fronts break the contacts composing the interface separating the bodies to enable their relative motion. The most general type of frictional motion takes place when the two bodies are not identical. Within these so-called bimaterial interfaces, the onset of frictional motion is often mediated by highly localized rupture fronts, called slip pulses. Here, we show how this unique rupture mode develops, evolves, and changes the character of the interface's behavior. Bimaterial slip pulses initiate as "subshear" cracks (slower than shear waves) that transition to developed slip pulses where normal stresses almost vanish at their leading edge. The observed slip pulses propagate solely within a narrow range of "transonic" velocities, bounded between the shear wave velocity of the softer material and a limiting velocity. We derive analytic solutions for both subshear cracks and the leading edge of slip pulses. These solutions both provide an excellent description of our experimental measurements and quantitatively explain slip pulses' limiting velocities. We furthermore find that frictional coupling between local normal stress variations and frictional resistance actually promotes the interface separation that is critical for slip-pulse localization. These results provide a full picture of slip-pulse formation and structure that is important for our fundamental understanding of both earthquake motion and the most general types of frictional processes.

| S-EPMC7306773 | biostudies-literature

100 km wear-free sliding achieved by microscale superlubric graphite/DLC heterojunctions under ambient conditions.

Project description:Wear-free sliding between two contacted solid surfaces is the ultimate goal in the effort to extend the lifetime of mechanical devices, especially when it comes to inventing new types of micro-electromechanical systems where wear is often a major obstacle. Here we report experimental observations of wear-free sliding for a micrometer-sized graphite flake on a diamond-like-carbon (DLC) surface under ambient conditions with speeds up to 2.5 m/s, and over a distance of 100 km. The coefficient of friction (COF) between the microscale graphite flake, a van der Waals (vdW) layered material and DLC, a non-vdW-layered material, is measured to be of the order of [Formula: see text], which belongs to the superlubric regime. Such ultra-low COFs are also demonstrated for a microscale graphite flake sliding on six other kinds of non-vdW-layered materials with sub-nanometer roughness. With a synergistic analysis approach, we reveal the underlying mechanism to be the combination of interfacial vdW interaction, atomic-smooth interfaces and the low normal stiffness of the graphite flake. These features guarantee a persistent full contact of the interface with weak interaction, which contributes to the ultra-low COFs. Together with the extremely high in-plane strength of graphene, wear-free sliding is achieved. Our results broaden the scope of superlubricity and promote its wider application in the future.

| S-EPMC8776547 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data