A contact solver suitable for tyre/road noise analysis

Road traffic noise is a major environmental problem in modern society. The interaction between tyre and road surface, the major noise source, is non-linear and is best described in the time domain. The currently used contact models for acoustic analyses have problems with either accuracy or calculation speed. At the Structural Dynamics and Acoustics group of the University of Twente an alternative contact algorithm has been developed. The characteristic feature of this algorithm is that, while solving the set of equations, the contact condition, i.e. the condition stating that there is no overlap between the bodies, is satisfied exactly. Hence, there is no need for contact elements or contact parameters. The possibility to optimize and speed up the algorithm, using multigrid is the major advantage of the new approach. In this paper the contact algorithm is applied to a two-dimensional finite element model. Coulomb friction is taken into account. Some test simulations illustrate the ease of the algorithm. The model will be extended and non-linear material behaviour will be added. Multigrid and multilevel will be used to speed up the calculation. The goal is to compute the vibrations and radiated noise pattern of a profiled tyre rolling on a road.