7. Contacts with Elastomers

Rubber and other elastomers play a large role in many tribological applications. They are used where large frictional forces or large deformations are needed. These materials are especially used for tires, transportation rollers, shoes, seals, rubber bands, in electronic devices (e.g., contacts for keyboards) as well as applications for adhesion. When compared to purely elastic contacts, the calculation of elastomer contacts is made more difficult by the fact that they exhibit a time-dependent behavior, which is also normally characterized by a large spectrum of relaxation times. The correct mechanical description must, therefore, take several orders of magnitude in characteristic times into account. The multi-scalar properties of the surface roughness are supplemented here by the multi-scalar character of the relaxation of the material, which makes the numerical simulation of elastomers especially complicated. It is, therefore, important to develop fast simulation methods for the calculation of contact and frictional properties for this class of materials. In this chapter, we will show how the method of dimensionality reduction can be generalized to contacts of elastomers with arbitrary linear rheology.