Experiments:

  • Difference between static and dynamic friction
  • Friction forces as a function of
    * normal force
    * sliding velocity (relative velocities of the
    friction partners)
    * Material pairing
    * Surface properties of the friction partners
    * Size of the contact area
  • Determination of friction coefficients

Specifications:

  • Mechanical friction between 2 solid bodies
  • Friction body stationary, support friction
    surface in a moving carriage
  • 4 friction bodies with 2 different surfaces
  • Different support friction surfaces with a total
    of 4 different surfaces
  • Carriage driven by cable pulley and motor
  • 2 driving velocities via a graduated cable drum
  • Force measuring unit: force gauge
  • Force measuring unit height-adjustable
  • Lines of action of friction force and tensile
    force always paralle

Friction is a key factor in mechanical engineering. Static friction needs to be adequate to fix components to each other, such as parking brakes, self-locking threads and frictionally engaged connections. Dynamic friction needs to be kept as low as possible, such as on bearings, in guideways or in shaping tools. Consequently, great attention is paid to the topic in engineering mechanics, and understanding of it is enhanced by clearly laid-out experiments. TM-1344 provides a broad range of experiments relating to static and dynamic friction between solid bodies which are in contact with each other and moving relative to each other. Various influences on friction can be investigated, such as surface properties and material pairing. A support friction surface slides beneath the stationary friction body. The support friction surface is held in a carriage which is drawn along by a motor at uniform velocity by a motor. The friction body is connected to a height-adjustable force measuring unit. This ensures that the lines of action of friction force and tensile force are parallel. The force measuring unit is essentially a force gauge which is fitted independently to compensate as far as possible for slip/stick effects and so indicate a mean friction force (with no spiking). Different support surfaces and four friction bodies are available. The normal force can be varied by adding weights. Experiments can be performed at two constant velocities.