Tire/wet road friction depends on two road-surface texture scales: the macrotexture (centimeterto millimeter dimensions) is responsible for the speed dependency of friction, and the microtexture (submillimeter dimensions) is responsible for the friction level at any speed. This paper deals firstly with the description of road-microtexture, the macrotexture scale being well documented. Consideri...

This paper presents experimental measurements of the approach and rebound of a particle colliding obliquely with a wall in a viscous fluid. Steel and glass particles 12.7mm in diameter were used. The experiments were performed using a thick Zerodur wall (a glass-like material) with various mixtures of glycerol and water. Normal and tangential coefficients of restitution were defined from the ra...

We consider two perfectly smooth featureless surfaces at T = 0, defined only by their respective dielectric functions, separated by a finite distance, and ask the question of whether they can experience any friction when sheared parallel to their interface. We find large frictional effects comparable to everyday frictional forces provided that the materials have resistivities of the order of 1 ...

An enhanced dynamic force model of a type of small and soft McKibben-type pneumatic muscle (PM) actuator has been developed. This model takes the factor of external loads and a more sophisticated form of friction into account, and is presented as a polynomial function of pressure, contraction length, contraction velocity and external load. The coefficients in this model are determined from a se...

AWH-Tk paper tre8ts the bramission of wave motion from one solid to rnotber when the bodies ue hitially spurted by I: small pp. If a pulse of elastic waves strikes the surface of one of the solids and the rmplitude of the pulw ir iaqe enough, I& solids can come into con&t and interact locally. The dynamic interaction is treated using Coulomb’s friction law, and a method is presented for finding...

We define a set of orthogonal functions on the complex projective space CPN−1, and compute their Clebsch-Gordan coefficients as well as a large class of 6–j symbols. We also provide all the needed formulae for the generation of high-temperature expansions for U(N)-invariant spin models defined on CPN−1.

Nowadays titanium alloys are extensively used for aerospace and biomedical applications. However, despite good mechanical properties and excellent corrosion resistance they possess poor wear resistance and a tendency to galling and seizure. In this study the tribological properties of experimental Ti-Si-Zr based alloys were studied using a standard ball-on-disc wear testing system. The wear and...

Here we demonstrate the effectiveness of an electroresponsive aqueous silk protein polymer as a smart mechanical damping fluid. The aqueous polymer solution is liquid under ambient conditions, but is reversibly converted into a gel once subjected to an electric current, thereby increasing or decreasing in viscosity. This nontoxic, biodegradable, reversible, edible fluid also bonds to device sur...