"Walking-Mode Maps", based on Slip/Non-Slip criteria, are proposed. Slip/Non-Slip criteria are expressed as follows: for a slip to occur: |F(h)/F(n)|(h) > or = mu(s) or |F(h)/F(n)|(t) > or = mu(s); for no slip to occur: |F(h)/F(n)|(h) < mu(s) or |F(h)/F(n)|(t) < mu(s). |F(h)/F(n)|(h) and |F(h)/F(n)|(t) are the maximum peak value of the traction coefficient at heel-strike and toe-off respectivel...

Introduction: When using sliding mechanics for space closure during orthodontic treatment, friction occurs at the bracket-wire interface. The aim of this study was to evaluate the frictional resistance between monocrystalline (ICE) brackets and Stainless Steel, Beta TMA and NiTi wires. Methods: In this experimental study, we used 5 different types of orthodontic wires. Brackets and wires wer...

In the discrete element simulation of granular materials, the modelling of contacts is crucial for the prediction of the macroscopic material behaviour. From the tribological point of view, friction at contacts needs to be modelled carefully, as it depends on several factors, e.g. contact normal load or temperature to name only two. In discrete element method (DEM) simulations the usage of Coul...

The frictional resistance on a fault during slip controls earthquake dynamics. Friction dissipates heat during an earthquake; therefore, the fault temperature after an earthquake provides insight into the level of friction. The Japan Trench Fast Drilling Project (Integrated Ocean Drilling Program Expedition 343 and 343T) installed a borehole temperature observatory 16 months after the March 201...

The quasi-static mechanical response of grains under cyclic loading is studied in this contribution by means of a three-dimensional Molecular Dynamics scheme. The response of the system is characterized by an accumulation of plastic deformation with the number of cycles. For the deviatoric stress and strain, a quasi-periodic ratchet-like behavior is observed. Results are presented for different...

Cf = skin friction coefficient CD = drag coefficient CDf = friction drag coefficient CDp = pressure drag coefficient h = step height M0 = freestream Mach number Patm = atmospheric pressure Pi = stagnation pressure Re = freestream Reynolds number Ti = stagnation temperature U = velocity U = normalized velocity Uτ = friction velocity X = longitudinal coordinate Z = vertical coordinate Z = normali...

The widely used PASCO laboratory equipment is an excellent way to introduce students to many topics in physics. In one case, PASCO’s equipment may be too good! Various experiments exist for calculating the kinetic coefficient of friction by measuring the acceleration of a sliding object under some constant force. With ever more accurate equipment, such as electronic motion sensors, students are...

tan films with different n2 partial pressure were deposited on 304 stainless steel using the magnetron sputtering method. the effect of gas pressure on the mechanical property, morphology and phase structure of the films is investigated by x-ray diffraction (xrd), atomic force microscopy (afm), microhardness testing, friction coefficient measurements, and wear mechanism study. the xrd results c...