This paper presents the development of a condition monitoring method for wet friction clutches which might be useful for automatic transmission applications. The method is developed based on quantifying the change of the relative rotational velocity signal measured between the input and output shaft of a clutch. Prior to quantifying the change, the raw velocity signal is preprocessed to capture...

We present an entirely analytic, leading log order determination of the friction an electroweak bubble wall feels during a first order electroweak phase transition. The friction is dominated by W bosons, and gives a wall velocity parametrically ∼ αw, and numerically small, ∼ .01 −− 0.1 depending on the Higgs mass.

In this paper, we design an adaptive controller to compensate the nonlinear friction model when the output is the position. First, we present an adaptive differential filter to estimate the velocity. Secondly, the dynamic friction force is compensated by a fuzzy adaptive controller with position measurements. Finally, a simulation result for the proposed controller is demonstrated.

Vortex extrusion (VE) is a severe plastic deformation technique which is based on the synergies between high strain accumulation and high hydrostatic pressure. Such a high amount of pressure, places a mandate to seek the method for investigation of the load under processing conditions. For this, kinematically admissible velocity field and upper bound terms based on Bezier formulation are develo...

-We describe slip-rate dependent friction laws based on the Coulomb failure criteria. Frictional rate dependence is attributed to a rate dependence of cohesion c and friction angle qS. We show that differences in the stress states developed during sliding result in different Coulomb friction taws for distributed shear within a thick gouge layer versus localized shear within a narrow shear band ...

A conventional description of the effect of meniscus friction is based on the concept of the dynamic contact angle u, which depends on the meniscus velocity V according to the Tanner law, u}V. However, recent high-resolution experiments on spontaneous uptake of wetting fluids by capillaries have questioned the universality of the Tanner law. We analyze a mechanism underlying the phenomenologica...

The overall object of this paper is a systematic study of gaseous flows and thermal transport in twodimensional microand nano-channels using direct simulation Monte Carlo (DSMC) method. In the flow study, a validation of DSMC code was conducted by simulating a continuum flow in microchannel and the results show that the discrepancy of friction coefficient from theoretical prediction is well bel...

Experimental investigation of the coefficient of sliding friction in rock at normal stress and sliding velocity of typical earthquakes (10–100 MPa and 0.01–1 m/s) is necessary to develop velocity-dependent constitutive relations useful for earthquake rupture simulations. The velocity dependence of rock friction is best explored in parametric studies of interfacial friction by imposing step-like...

A study of di erent classes of controllers for mechanisms under the in uence of low velocity friction is conducted. Many methods are proposed in the literature for friction compensation, but there has been no signi cant analysis of these methods with respect to each other. Also lacking in the literature is some form of categorization, under which it is possible to describe and study their perfo...

We report on detailed laboratory experiments designed to illustrate the frictional behavior of granular volcanic debris. The materials include pyroclastic flow debris from Soufrière Hills Volcano, Montserrat, and from Stromboli Volcano, Italy, and lahar deposits from Mount St. Helens. Experiments were conducted in a servo-controlled, double-direct shear apparatus under conditions of displacemen...