ABSTRACT
To determine the influencing parameters on tire tread properties and in particular the friction behaviour, it is necessary to investigate the contact conditions between rubber and rough substrates. The contact properties between two materials are affected by a large number of extrinsic and intrinsic factors such as substrate roughness, surface energy, temperature, load, sliding speed, lubrication and elastomeric material properties. In this work, the gap between a model substrate (multi-indenter) and contacting tire tread compounds with varying viscoelastic properties as a function of the normal load and sliding speed is investigated. Therefore, a new experimental technique based on laser distance measurements is used to determine the relaxation of a rubber block into cavities of a model substrate and thus the depth of rubber indentation depending on sliding distance. In this way, a validation of the contact theories and FEM simulations concerning crucial parameters such as the indentation depth and contact area could be carried out.
