Loss of braking power and rubber skidding on a wet road is still an open physics problem, as neither the hydrodynamic effects nor the loss of surface adhesion that are sometimes blamed really manage to explain the 20-30% observed loss of low-speed tyre-road friction. Here we report a novel mechanism based on sealing of water-filled substrate pools by the rubber. The sealed-in water effectively ...

Natural contacting surfaces have remarkable surface mechanical properties, which has led to the development of bioinspired surface structures using rubbery materials with strongly enhanced adhesion and static friction. However, sliding friction of structured rubbery surfaces is almost always significantly lower than that of a flat control, often due to significant loss of contact. Here we show ...

Polyvinyl ester green composites were synthesized with walnut shell powder (WSP) by in-situ polymerization technique. The green composites have been evaluated for mechanical properties such as tensile strength, tensile modulus and hardness. Sliding wear loss, specific wear rate and coefficient of friction were investigated by using computerized pin-on–disc machine at normal applied loads of 20,...

The piston ring assembly is one of the key parts of internal combustion engine. Its performance decides engine power loss to over come friction force and determines the performance of the whole engine. As per the literature review it is reported 40 to 50 % of the total mechanical friction losses in piston ring cylinder wall interface. The present work mainly focused on study of basic tribologic...

Friction and wear, often treated as unrelated, distinct phenomena, are manifestations of the same dissipative physical processes occurring at sliding interfaces. Friction force dissipates power and generates entropy. Wear irreversibly changes a material structure, often with loss of material. Associated with both friction and wear is production of irreversible entropy by interfacial dissipative...

Attempts have been made for the first time to produce a friction material with thermal sensitive modulus by the inclusion of combined plastic/rubber properties of thermoplastic elastomers (TPE) as viscoelastic polymeric materials into the formulation for the purpose of increasing the damping behavior. In order to evaluate the viscoelastic parameters such as loss factor (tan δ) and elastic m...

The effect of friction in the thermal convection instability of granular fluids is studied by means of molecular dynamics simulations. It is found that the transitions between different convective states (zero, one, and two rolls) are primarily governed by the average energy loss per collisions and not by the friction and restitution coefficients separately, and can be roughly described in term...

Amber is a fossilized resin with a molecular structure similar to that of o t h e r s s i l hydrocarbons. It displays internal friction peaks similar to those of synthetic polymers and other macromolecular hydrocarbon materials. It is an excellent dielectric, and has a dielectric loss spectrum as well. We have utilized internal friction and dielectric loss spectra to elucidate some features of ...

attempts have been made for the first time to produce a friction material with thermal sensitive modulus by the inclusion of combined plastic/rubber properties of thermoplastic elastomers (tpe) as viscoelastic polymeric materials into the formulation for the purpose of increasing the damping behavior. in order to evaluate the viscoelastic parameters such as loss factor (tan δ) and elastic modul...

In the general framework of tracking control of hydraulic servo systems, this paper presents a comparison between two main possibilities to include friction information in the picture: experimental identification and estimation. Experiments were first conducted in order to find a suitable representation for friction in the system. We then looked at two observers reported in the literature (know...