Tribometer managing autumn leaf problem on railways worldwide

Since the 1800s, railway organizations have been struggling with low adhesion on the rail, especially during the Autumn season also known as the “slippery track season”. In Autumn, leaves fall on the rails and when train wheels crush the leaves, they become a layer of oil...Read More »


How can tribology help extend critical machinery service life?

Tribology is the science of interacting surfaces in relative motion. Basically, it studies friction, wear and lubrication – three phenomena linked to surface degradation and, thus, to machine reliability and performance. When machines wear out, they perform worse, are less productive and, finally, begin...Read More »


A Better Way to 3D Print Metallic Glass

In the last several years, 3D printing with plastics has advanced rapidly. Now, a team of researchers have shown that it may soon be as easy and practical to use metals with 3D printing.

Led by Jan Schroers, Yale professor of mechanical engineering & materials science, the research team used a...Read More »


The Evolution of Rotary Lip Seals

In the world of sealing, it seems as though there are as many varieties of pump applications as there are sealing solutions.

Many breakthroughs in technology have aided the evolution from braided packing to advanced mechanical seals, leading to remarkable gains in pump performance, efficiency and safety. Although mechanical seals are certainly...Read More »


Guidance Notes on Friction

In dry sliding between a given pair of materials under steady conditions, the coefficient of friction may be almost constant. This is the basis for two EMPIRICAL Laws of Sliding Friction, which are often known as Amontons’ Laws and date from 1699. They are in fact not...Read More »


Contact Mechanics Book

The Handbook on Contact Mechanics (Handbuch der Kontaktmechanik) co-authored by Honorary Professor of Tomsk Polytechnic University, head of the Department of System Dynamics and Friction Physics at Technical University Berlin, Valentin Popov, a TPU alumnus Emanuel Willert, and Assistant Professor of the Department of System Dynamics and...Read More »


Sharp knives - high friction

Trying to slice a tomato into thin slices with a dull knife can get a little scary. The harder the knife must be pressed downward before the skin is broken is directly related to the acceleration the knife experiences as it passes through the rest of...Read More »


On the history of elastohydrodynamics

Here we present an abstract to a paper devoted to the history of eastohydrodynamic theory and his founder – Alexander Mohrenstein-Ertel. This paper discusses in detailes the peculiar biography of the scientist and the early years of the theory development.

On the history of elastohydrodynamics: The dramatic destiny of Alexander...Read More »


Note on the history of contact mechanics and friction

No future without history! A great article on the history of great discoveries in the field of contact mechanics and friction was recently published by Elena Popova and Valentin L. Popov. Here we present the abstract of the article.

Abstract

Great discoveries are often perceived by subsequent generations as sudden...Read More »


How to get sprayed metal coatings to stick

Micrographs of a metal surface after impact by metal particles. Craters are formed due to melting of the surface from the impact. Image courtesy of the researchers.

“When spraying metal coatings, melting hurts rather than helps”, MIT research reveals.

When bonding two pieces of metal, either the metals must melt a bit...Read More »


Super-ballistic electron flow confirmed

Behaving like particles in a viscous fluid can help bunches of electrons squeeze through a tight space.

When many people try to squeeze through a passageway at the same time, it creates a bottleneck that slows everyone down. It turns out the reverse is true for electrons, which can move through...Read More »


Morphable surfaces could cut air resistance

Adding golf ball-like dimples to surfaces could reduce drag and improve efficiency of vehicles.

There is a story about how the modern golf ball, with its dimpled surface, came to be: In the mid-1800s, it is said, new golf balls were smooth, but became dimpled over time as impacts left permanent...Read More »


The science of slippery bananas

They’re yellow. They’re radioactive. And they’re very slippery. Yes, they’re bananas, and we have just found out why they’re so slippery.

So yellow … yes we all know that. But radioactive? Well yes, bananas are slightly radioactive because of small amounts of the naturally occurring isotope potassium-40. But the rate of...Read More »


Study into the Rheology of Cats wins big at 2017 Ig Nobel Prize

From the brain’s responses to cheese aversion to the fluid dynamics of cats, WIRED picks its favourite Ig Nobel Prize winners for 2017

The winners of the 2017 Ig Nobel Prize, the science awards given to “achievements that first make people laugh then make them think” have been announced, based around...Read More »


The ‘Origami Robot’ that can be ingested

Ever swallowed a button-battery? And wondered how to get it out? Have no fear, the origami robot is here!

That’s right, the Massachusetts Institute of Technology (MIT) has come up with a pill-sized origami robot, which will help motor the unwanted plastic and other non-dissoluble objects safely out of the...Read More »


Concrete strength is determined by internal friction

Cement materials, including cement paste, mortar, and concrete, are the most widely manufactured materials in the world. Their carbon footprint is similarly hefty: The processes involved in making cement contribute almost 6 percent of global carbon emissions.

The demand for these materials is unlikely to decline any...Read More »


Power generating floor from waste - thanks to triboelecric effect

Visitors to UW–Madison’s Union South walk across a section of floor designed and installed by College of Engineering researchers to capture the energy of footsteps and turn it into usable electricity. Photo: Adrienne Nienow

As thousands of visitors each day walk across a new...Read More »


Triboelectric charges on HDPE are strain induced

New research indicates how static electricity puts the charge in material, offering answer to centuries-old question

For centuries, scientists have tried to understand triboelectric charging, commonly known as static electricity.

Triboelectric charging causes toner from a photocopier or laser printer to stick to paper,...Read More »


Vanishing Friction

Illustration: Christine Daniloff/MIT and Alexei Bylinkskii

A new technique tunes friction between two surfaces, to the point where friction can vanish. MIT researchers developed a frictional interface at the atomic level. The blue corrugated surface represents an optical lattice; the red balls represent ions; the springs between them represent Coulomb forces...Read More »


Nanotechnology Flight Test

Mastering the intricacies of controlling matter at the nanoscale level is part of a revolutionary quest to apply nanotechnology to benefit industrial processes. A key element of that technology is the use of carbon nanotubes.

Carbon nanotubes are small hollow tubes with diameters of 0.7 to 50 nanometers and lengths generally...Read More »


Does Friction cause Friction Blisters?

What is friction?

There is more than one definition of friction. And this has confused our understanding of how it is involved in friction blister formation.

The Merriam-Webster Dictionary has two definitions of friction:

  1. the act of rubbing one thing against another
  2. the force that resists relative motion between two bodies in...Read More »

Keeping the Wind in Your Sails

 

Just like any mechanical device, a wind energy system needs timely, appropriate lubrication in order to function reliably and predictably. Wind turbines routinely withstand extremely demanding conditions: vibration, high mechanical loads, contamination and moisture are all potential threats to operational efficiency, especially in critical rotating components such as bearings and gears.

Turbine...Read More »


Friction: The Key to Rock Climbing

This article explains the vital role Friction has to play in Rock Climbing. Thanks to Richard Jones and Glen Harding for their input.

Friction is the magic ingredient in bouldering and rock climbing. It’s what makes the best moves and sequences subtle and surprising. Friction is a variable, some days it’s...Read More »


Modern Applications of Tribology

While Leonardo da Vinci commented on the effects of friction in the 1400s, it wasn’t until the mid-1960s that tribology was coined by Dr. H. Peter Jost and accepted as the term for the study and application of the principles of friction, lubrication, and wear.

In the early 1960s, there was...Read More »


Medical textiles and tribology

NOT LONG BEFORE MY LAST SKI TRIP, I was having a lot of lower back problems stemming from a bad fall years ago. Without getting into too much blood and gore, I have a pinched nerve and the associated arthritis from long-term inflammation. So the fix, at least enough to...Read More »


Tribology at Work on the Strings

There’s something about the moan and wail of a good gut-bucket slide guitar riff that can grab you by the innards and not let go. Any tribologist worth his salt is likely to have another reaction: “A bit high on the tribometer, that.”

Blues, bluegrass, and Hawaiian slide guitar fans know...Read More »


Tribological testing of materials for automotive industry

Quality Magazine have published an article about using benchtop mechanical testing to assess materials in the automotive industry,  saving time and money.

Full scale tests are often used to test the frictional behaviour of materials, to compare their wear characteristics, friction curve and...Read More »


Feeling of a touch for robots through artificial intelligence and contact area patterns

Eight years ago, Ted Adelson’s research group at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) unveiled a new sensor technology, called GelSight, that uses physical contact with an object to provide a remarkably detailed 3-D map of its surface.

Now, by mounting GelSight sensors on the grippers of robotic arms,...Read More »


The correct lubricant: a practical guide to choose lubricating oil

‘The correct lubricant’ covers basic practical information about lubricants in automotive and industrial areas. It is written for users of lubricants, giving only what is essential to know and useful for them. It could also be used by professionals in the field who must explain various aspects of...Read More »


Triboelectricity to collect wave power

Nature provides three sources of energy for free: sunlight, air and gravity. Solar and wind power are increasingly exploited, gravity less so. Hydraulic power plants harvest energy from flowing rivers. Tidal energy can be gathered along some inlets and coasts. But few places are suitable for dams or...Read More »


Grab things like a Gecko: a new gripping system

Researchers at Carnegie Mellon University and Max Planck Institute for Intelligent Systems have developed a soft gripping system that uses differential air pressure and a gecko-inspired adhesive for exceptional bonding to three-dimensional objects. The findings were published in Proceedings of the National Academy of Sciences this week.

A soft gripping system...Read More »


Ice crystals formation is controlled by the surface texture - new study shows

WASHINGTON (May 17, 2017)—A new study examining how ice forms from pure water found that the geometry of the surface that water is on can have an effect on whether or not it freezes, suggesting that surface geometry plays an important role in ice formation. Greater understanding of...Read More »


No Friction - Bad Earthquake

It is a common trope in disaster movies: an earthquake strikes, causing the ground to rip open and swallow people and cars whole. The gaping earth might make for cinematic drama, but earthquake scientists have long held that it does not happen.

Except, it can, according to new experimental research from...Read More »


Impact of water on Grease film thickness in rolling point contacts

In a rolling bearing, the load transmission is often accompanied by high contact stresses which may eventually lead to wear and/or fatigue. In order to ensure separation of moving parts leading to a long life, bearings are usually grease or oil lubricated. The separation of the moving parts in a...Read More »


After the Mystery of Rotary Lip Seals

Lip seals compete with mechanical face seals in sealing oil or grease in rotary shaft applications. Under certain running conditions both kinds of seals can be used however, the latter ones are generally used for applications where a significant pressure difference needs to be preserved. Rotary lip seals are preferred...Read More »


Friction is a possible reason for SpaceX Falcon 9 explosion

September 1 of 2016 at Cape Canaveral SpaceX lost is Falcon 9 rocket on a launch pad due to dramatic explosion. During a routine preflight fueling test, the  rocket and the $200 million Israeli Earth communication satellite Amos-6 were lost. No one was injured.

A...Read More »


Happy New Year and 2016 tribonet Awards

The holidays are here!  And here at tribonet, we would like to wish all our readers the very best for the new year.  Many blessings, love and happiness to the entire tribonet community!

It was a great year for tribonet, thanks to the readers and the authors! With the ending of...Read More »


What contributes to thicker grease films ?

A rolling bearing preferably runs under EHL conditions. The film thickness between the rolling elements and the rings is determined by the lubricant properties, operating conditions and bearing design. During the initial phase of operation, macroscopic flow (churning) of the grease takes place. It is usually during this churning phase...Read More »


Argonne Embraces Concept of "in operando" Formation of Carbon-based Tribofilms

Earlier this month, tribologists and physicists at the U.S. Department of Energy (DOE) Argonne National Laboratory published news of their (self-described) “self-healing diamond-like carbon coating [that] could revolutionize lubrication” in the journal Nature.  The researchers claim...Read More »


Contact Area vs. Load: Simple Scaling Laws

“God made the bulk; surfaces were invented by the devil”, a Nobel prize winning physicist Wolfgang Ernst Pauli said. In tribology, as in many other sciences, surface features (asperities, roughness) play an important role. In many cases, the surface roughness dramatically alters the friction, contact area,...Read More »


Small Particles - Big Problems

Tiny particles are all over around us and sometimes they may create problems. This is especially of concern with metal particles formed due to wear in man-made engineering devices. Particles formed in car disk brakes may harm lung cells, metal particulate limits the service life of artificial hip...Read More »


Determining Fatigue Wear Using Wear Particle Analysis Tools

...Read More »

Nordtrib 2016: conference summary and outlook on the field of tribology 50 years after the Jost report

Nordtrib 2016 came to a close last Friday and I returned home inspired and energized for the next stint in my PhD research. This post is an overview of the conference and summarises the outlook on the field for the years to come based on the round table discussions and...Read More »


Who is The First? Leonardo da Vinci!

Leonardo di ser Piero da Vinci, the famous Italian engineer, architect, painter, musician, mathematician can also be considered as The First Tribologist! Although the term itself was invented approximately 450 years after Leonardo da Vinci (1452-1519), he was the first one to perform the systematic study on friction,...Read More »


Bio-lubricants and Environmentally Acceptable Lubricants (EAL)

The increasing awareness on environmental pollution caused by many chemicals, including lubricants, promotes the use of environmentally friendly products. There is a clear trend towards a more responsible use of lubricants and several legislations already limit the use of certain oils in some applications. Bio-lubricants are present in construction, mining...Read More »


In Situ Nanopolishing (ISN): A New Lubrication Paradigm Aimed at Permanent Surface Perfection

All conventional lubricants borne of classic hydrodynamic theory are designed to provide lubricity. Inherent in the desire to provide lubricity to mechanical systems is the desire to protect the interacting metal surfaces from wear. Much effort in tribology...Read More »


Surface Replication Compounds

The first challenge when measuring a surface topography via optical techniques is getting the sample to the lab. Although optical surface roughness measurement does not damage the component per se (NDT), the fact of fitting it into a microscope generally requires the destruction of the original component. The surface replication...Read More »


Wear in nanoscale: optimum AFM tip roughness

Wear is a gradual removal of the material of the bodies during their interaction. The process appears in many mechanical systems, ranging from large scales, as in wind mills, to nanoscales, as in the AFM tip – substrate contact. The macroscale wear is a relatively well developed field of tribology,...Read More »


"Car 2020" and Tribology Research

Friction has been a challenge for the mankind throughout the whole history since it resists the motion. It resists the transportation of goods. And transportation shares 20% of the global energy consumption and approximately 18% of the greenhouse gas emissions. Out of this share, road transportation builds up to 72%...Read More »


Ice Lubrication and the Forbidden City

Forbidden City is a historical symbol of China, located in the center of Beijing and was constructed between 1406 and 1420 . It served as an imperial palace for almost 500 years and consists of 980 buildings on 180 acres area. Large number of massive buildings required mining and transportation...Read More »


So, what is it, superlubricity?

From the first friction quantitative experiments by Leonardo da Vinci (1452-1519) and most notably from our everyday life experience, it is known that there is an inevitable force opposing to the initiation of motion of one body on the surface of another. This force has to be exceeded, in order...Read More »


Modeling rough adhesive surfaces

Imagine a new type of tyres whose structure has been designed to have greater adhesion on the road. Quite a timely discussion during the long winter nights. French physicists have now developed a model to study the importance of adhesion in establishing contact between two patterned, yet elastic, surfaces. Nature...Read More »