Experimental investigation of viscoelastic rolling contacts: a comparison with theory

We present a detailed experimental investigation on viscoelastic rolling contacts. The tests focus on contact area, penetration and viscoelastic dissipation measurements between a nitrile rubber ball rolling on a glass disc. Each of the measured parameters is shown to be dependent on the rolling speed and normal load and has, therefore, been used to assess the main differences between viscoelastic and linear elastic rolling contacts. Experimental outcomes are compared with numerical predictions of the theory proposed by Carbone and Putignano (J Mech Phys Solid, 2013). A good agreement is found between experiments and theoretical predictions, thus demonstrating the validity of the numerical approach. This has important implications for modelling the behaviour of real viscoelastic materials, whose response is characterised by a wide distribution of relaxation times. The presented methodologies and results can be applied directly or are of relevance to a number of engineering components, such as tires and seals.