3. Specific tribological measurement problems

3.1 Vibrations

The dispersion of standardized friction test results is a major obstacle to the use of this type of test, particularly in the industrial world. There are many reasons for this dispersion: the quality of the test specimens, signal acquisition and processing resources, laboratory humidity and the dynamic characteristics of the tribometer. During the first VAMAS test campaign (first round robin test), vibrations were already observed in the wiper during the test. In the case of the steel/steel test, the vibrations were much greater than in the other cases, demonstrating that dynamic stresses at the contacting surfaces can differ from one material to another when the nominal test conditions are identical.

Vibrations generated by friction can be...