Period I, when the cutting distance is less than half of the size of the abrasive particle, the friction coefficient fluctuates violently in certain range due to surface effect of the material; while in period II, all the friction coefficients fluctuate in very small range, and the friction coefficients remains steady state at different angles.
At least for the range of this study, while increasing the amount of fluorine incorporated in both network series, dynamic friction is reduced due to surface migration of fluorine species during polymerization.
where τ is the shear strength, c' is the effective cohesion, σ is the total normal stress, u a is the pore air pressure due to surface tension, φ′ is the effective friction angle, u w is the pore water pressure, and φ b is the angle expressing the rate of the increase in strength related to matric suction.
The efficiency drops with increase in surface roughness due to surface roughness effect, flow losses and external disc friction.
The possible two mechanisms are friction reduction by pore-fluid pressure increase and elastic stress change due to surface load on faults.
Friction coefficient decreases with increasing temperature at high sliding velocities (from 0.79 to 1.96 m/s) due to surface lubrication.
That increasing pad thickness protected the head without increasing neck loads suggests that the increased cervical spine injury incidence previously observed in cadaveric impacts to padded surfaces relative to lubricated rigid surfaces was due to increased surface friction rather than pocketing of the head in the pad.
We noticed that non-uniform double helices can be produced due to the surface friction induced by the self-contact.
(iii) The non-specific adhesion forces (due to static friction, surface tension, Van-der-Waals forces of the semiconductor chips on the polyimide web is important since these forces impacts the amount of spreading of the chips.
Finally, the viscous shear force, term (v) in Equation (2), represents drag on the control surface due to fluid friction.
