Tribology 2 – Friction and Wear

Tribology is the science that deals with every problem of friction, wear and lubrication. Tribology is of fundamental importance for understanding what happens at the interfaces of every articulated coupling in machines as well as in the human body.

The Tribology Group of the University of Pisa is involved in studies on friction and wear related to environmental and human aspects (green tribology, biotribology). Experimental activity is usually combined with numerical and theoretical studies (see Activity on Wear prediction).

Despite being a well-known concept of mechanics, friction still deserves many research aspects. In order to investigate some of the factors affecting both static and dynamic friction coefficients, a simple modular experimental apparatus has been specifically designed and built (Fig.1). Arbitrary motion laws can be defined and both conformal and non-conformal contacts can be tested by using specifically designed specimens. The apparatus can be used in two different configurations, alternatively controlling the displacement of the upper specimen or lower specimen to estimate the influence of the inertial actions. A sample results is shown in Fig. 2.

Fig. 1 – Friction test rig.
Fig. 2 – Sample trends of measured force and displacement.

Research group
Enrico Ciulli, Francesca Di Puccio, Lorenza Mattei

External collaborations:
AC2T research GmbH (


PRA 2015

Main publications:

  • L. Mattei, F. Di Puccio, E. Ciulli, “A comparative study of wear laws for soft-on-hard hip implants using a mathematical wear model“, Tribology International, Vol. 63, 66-77, 2013.
  • E. Ciulli, L. Mattei, F. Di Puccio, “Friction and wear comparison tests on different surface coatings and shapes”, Proceedings of the 14th World Congress in Mechanism and Machine Science, IFToMM, Taipei, Taiwan, 25-30 October, 2015, ISBN 978-986-04-6098-8, p.1-8, DOI 10.6567/IFToMM.14TH.WC.OS18.022
  • F. Di Puccio, E. Ciulli, “Theoretical and Experimental Investigation on Friction in Lubricated Line Contacts with Different Materials and Textures in Presence of Wear“, Key Engineering Materials, Vol. 681, Wear and Contact Mechanics II, 142-154, Feb. 2016, ISBN-13: 978-3-03835-745-2, ISSN: 1662-9795, DOI 10.4028/
  • Ciulli E (2019) Tribology and Industry: From the Origins to 4.0. Front. Mech. Eng. 5:55.