A new dynamic friction model for modeling of elliptical vibration assisted turning (EVAT) was developed in this research. The periodic change of the friction force direction is known to be one of the most important causes of this phenomenon. In modeling of machining processes (including the EVAT process), static Coulomb friction model was employed by most of the researchers. Because of the peri...

We have been developing a process design CAE system to predict die wear life in the process design stage for the hot forging of steel. Our goal is to reduce production costs by shortening the development period, while maximizing the life of the die. In our system, we use an expression that defines the relationship between die wear, die strength, and friction factors, such as die pressure, slidi...

Friction was measured on a single molybdenum disulfide (MoS2) nanotube and on a single MoS2 nano-onion for the first time. We used atomic force microscopy (AFM) operating in ultra-high vacuum at room temperature. The average coefficient of friction between the AFM tip and MoS2 nanotubes was found considerably below the corresponding values obtained from an air-cleaved MoS2 single crystal or gra...

Aim of this study is to evaluate a new three-equation turbulence model applied to flow and heat transfer through a pipe. Uncertainty is approximated by comparing with published direct numerical simulation results for fully-developed flow. Error in the mean axial velocity, temperature, friction, and heat transfer is found to be negligible. Keywords—Heat Transfer, Nusselt number, Skin friction, T...

Articles you may be interested in Velocity dependence of friction and Kramers relaxation rates Is slow thermal isomerization in viscous solvents understandable with the idea of frequency dependent friction? We present new data on the ground state isomerization rate of DODeI and compare our results to previously obtained excited state data. We find that the one-dimensional Kramers expression doe...

In the present work the influence of a LuGre type friction law [cf. to C. Canudas de Wit, H. Olsson, K.J. Aström, P. Lischinsky, A new model for control of systems with friction, IEEE Transactions on Automatic Control 40 (1995) 419] on the fundamental mechanisms resulting in linear instability of steady sliding in point contacts is investigated. Both a velocity-dependent kinetic friction coeffi...

The Alpine Fault, New Zealand, is a major plate-bounding fault that accommodates 65-75% of the total relative motion between the Australian and Pacific plates. Here we present data on the hydrothermal frictional properties of Alpine Fault rocks that surround the principal slip zones (PSZ) of the Alpine Fault and those comprising the PSZ itself. The samples were retrieved from relatively shallow...

Metal forming processes, compared with machining ones, reduce production steps and increase manufacturing speed in addition to saving raw material. In this paper, forming process of column of a steering mechanism is investigated by finite element analyses and experimental tests; and optimum die design parameters are found. Forming process parameters including die opening angle, bearing length, ...

Atomic force microscopy has been used to study the effect of temperature on normal forces and friction for the room temperature ionic liquid (IL) ethylammonium nitrate (EAN), confined between mica and a silica colloid probe at 25 °C, 50 °C, and 80 °C. Force curves revealed a strong fluid dynamic influence at room temperature, which was greatly reduced at elevated temperatures due to the reduced...