Stick-Slip / Friction Review

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Stick-Slip / Friction

Stick-slip Friction. To the unaided eye the motion of sliding objects appears steady. In reality this motion is jerky or intermittent because the objects slow during shear periods and accelerate following the shear. This process is continuously repeated while the objects are sliding.

During shear periods, the static friction force F controls the speed. Once shearing is completed, the kinetic friction force F_s controls the speed and F_k the object accelerates. This effect is known as stick-slip.

In well lubricated machinery operated at the proper speed, stick-slip is insignificant, but it is responsible for the squeaking or chatter sometimes heard in machine operation. Machines that operate over long sliding surfaces, such as the ways of a lathe, are subject to stick-slip. To prevent stick-slip, lubricants are provided with additives to make F_s less than F_k .

Related:

• Laws of Sliding Friction Unlubricated Surfaces
• Rolling Friction
• Coefficient of Friction Equation and Table Chart