7 shows the static friction
dragging power and the positive conveying power as a function of rotor angle and eccentricity.
Different ways of pushing and pressing on the blocks can change the coefficient of static friction
by as much as a factor of about two, they found.
Anomalous Density Dependence of Static Friction
in Sand, Physical Review E 54(2): 2005-2009.
In practice, the static friction
of a cylinder has an uneven distribution along the cylinder and varies with the environment changes .
Tests were conducted to determine the coefficient of static friction
at three load stress levels for maple bearings treated with eight types of lubricant.
The peak of maximum torque corresponding with static friction
is well represented in figure 4a.
The roller/rail combination suffers from having to overcome static friction
to get it moving.
The coefficient of static friction
is the tangent of the angle of a ramp on which a block just starts to slide down.
Algor adds that the new capabilities also allow for the consideration of static friction
effects by simply specifying a static friction
coefficient or by using the default.
Physically, at this point the static friction
has become greater than the restoring spring force and thus prevents the block from moving.
Since the bearing surface is a pressurized fluid film, it has virtually zero static friction
and is free from the small disturbances of slide movement typical with precision rolling and slide bearings.
For contacting surfaces at rest, the initial coefficient of friction was defined as the coefficient of static friction