thermo-mechanical analysis of stationary rolling tires

• Applicant: Professor Dr.-Ing. Udo Nackenhorst
• Subject Area: Mechanics
• Term: from 2010 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 189716259

The thermo-mechanical tire model developed during the first funding period shall be extended by a detailed model for the hysteretic loss which results from the local asperity contact of the tread rubber with the rough surface. These research activities are motivated by the hypothesis that the dissipative effects caused by the asperity contact of the soft inelastic tread rubber with the rough road surface causes a mentionable contribution to the total rolling loss of tires. In a first working package finite element models for detailed studies of the contact of soft rubber with rough road surfaces will be developed. The road is described as rigid body for simplicity; the rough-ness will be modeled via a spectral description. For the tread rubber the sophisticated thermo-mechanical inelastic constitutive models derived in the first funding period will be assumed. The ther-mo-mechanical response will be studied under tire typical operational conditions. Based on these detailed studies at the mesoscopic length-scale a constitutive contact law for macro-scopic simulations shall be derived. A surface free energy density function will be developed from which the surface traction and the related tangent operators can be derived. Motivated by the physics of the asperity contact we will not follow the classical concept that splits normal and tangential contact traction a priory. In addition a dissipation function will be developed, from which the global heat production due to the inelastic effects in the asperity contact can be derived. The parameters for these functions, e.g. road surface texture characteristics and road temperature, will be identified from the detailed contact investigations performed in step one. In a third working package the developed constitutive contact laws will be implemented for a macro-scopic simulation of stationary rolling tires. Goal of this research is to provide a powerful simulation technique which enables studies on the contribution of different assembly parts to the total rolling loss of stationary rolling tires.

• DFG Programme: Research Grants