Stribeck curve

Stribeck curve with friction µ versus speed v

The Stribeck curve describes the course of the friction force as a function of the friction speed in the case of hydrodynamic friction . It is named after the German researcher Richard Stribeck , who u. a. dealt with problems of material hardness and shaft bearings and published this curve in 1902.

properties

The main areas of the Stribeck curve are:

• Static friction (v = 0)
• Boundary friction (1 in the diagram)
• Mixed friction (2 in diagram)
• Fluid friction (3 in the diagram)

If there is no relative movement, there is static friction. As soon as a force acts that is greater than the static friction force F _H , the contact points break open and the relative movement begins. The friction is high and initially little dependent on the speed, as long as the molecules of the lubricant can be completely displaced at the newly formed contact points - solid-state or boundary friction prevails. If this is no longer the case at higher relative speeds, i.e. at least a few molecules of the lubricant separate the base body from the counter body even on the roughness hills, then the friction drops drastically. The friction within the lubricating film (hydrodynamic or elasto-hydrodynamic friction) increases approximately linearly with the speed (III). The transition from mixed friction to fluid friction is called the notch point. In principle, the wear is lowest in the area of ​​fluid friction.

See also

• Stick-slip effect
• Hydrodynamic plain bearing

Individual evidence

1. ↑ Richard Stribeck: The essential properties of plain and roller bearings . In: Journal of the Association of German Engineers , vol. 46 (1902), pp. 1341–1348, 1432–1438 and 1463–1470.

Web links

• Tribology on surfaces with tailor-made topographical design (accessed October 11, 2019)
• Stribeck curves: A powerful tool for tribology briefly explained (accessed October 11, 2019)
• Determination of the lubrication and friction conditions in the contact between the piston ring and the cylinder liner of combustion engines in a model tribometer (accessed on October 11, 2019)
• Tribological investigations on the friction and wear behavior of model greases on a ball-disc tribometer (accessed October 11, 2019)
• For the modeling and compensation of dynamic friction in actuator systems (accessed on October 11, 2019)