Patrick Moldenhauer

Simulation and Experimental Investigations of the Dynamic Interaction between Tyre Tread Block and Road

The dynamic behaviour of a tyre tread block is described by a modularly arranged model with a high numerical efficiency. Special emphasis is laid on the interaction between structural dynamics and contact mechanics. Parameter-dependent friction is implemented as well as a non-linear contact stiffness to consider the properties of the rough surface. The model includes local wear which influences the dynamic behaviour. The relevant parameters are obtained by experimental investigations. High-frequency stick-slip vibrations of the tread block occur e.g. on a corundum surface within a certain parameter range which are compared to simulation results. Furthermore, the model includes the rolling process of the tyre: the tread block follows a trajectory which is obtained from the deformation of the tyre belt. The results from simulations with a single tread block provide a deeper insight into highly dynamic processes that occur in the contact patch such as tyre squeal, run-in or snap-out effects.

Local effects between the tyre and the road

The tyre is the integral part of the vehicle that transmits all normal and tangential forces between the vehicle and the road. The tyre tread block is the only tyre component that is in direct contact with the road surface and is thus of special interest. However, the contact situation between the tyre and the road is a very complex one, and therefore all its details are usually unknown. The Institute of Dynamics and Vibration Research at Leibniz University Hanover (Germany) and the Insitute of Machine Elements, Design and Production of the Technical University Freiberg (Germany) investigate the local contact phenomena in the tyre/road contact and developed a modular model that describes the dynamic behaviour of tyre tread blocks, taking into account the contact effects.

Dynamic systems with rubber contacts in technical applications

Abstract This work deals with the experimental investigation and modelling of adhesion and friction of rubber. With the recently developed adhesion test rig, the contact partners can rapidly be separated while the contact force is measured. The results reveal a strong influence of the preload duration and preload level. Furthermore, a modular modelling concept for dynamic systems with rubber components undergoing sliding friction is presented and exemplified by a tyre tread block. The model considers the geometry of the rubber component, the parameter dependent friction, the roughness induced non-linear contact stiffness and the wear effects. The measurements of high frequency, self-excited tread block vibrations are performed on a tribometer test rig and compared to corresponding simulations with the proposed model.

Lokale Effekte zwischen Reifen und Fahrbahn

Der Reifen als integraler Bestandteil des Fahrzeugs ubertragt alle erforderlichen Normal- und Tangentialkrafte zwischen Fahrzeug und Fahrbahn. Der Reifenprofilblock ist die einzige Reifenkomponente mit direktem Kontakt zur Fahrbahn und ist somit von besonderem Interesse. Die genaue Kontaktsituation zwischen Reifen und Fahrbahn ist sehr komplex und deshalb in der Regel nicht im Detail bekannt. Das Institut fur Dynamik und Schwingungen der Leibniz Universitat Hannover und das Institut fur Maschinenelemente, Konstruktion und Fertigung der TU Bergakademie Freiberg untersuchen lokale Kontaktphanomene zwischen Reifen und Fahrbahn und stellen ein modular aufgebautes Modell vor, das unter Berucksichtigung der Kontakteffekte eine Beschreibung des dynamischen Profilblockverhaltens liefert.

Simulation of tire tread block dynamics with respect to complex contact phenomena

Vibrations of the tire structure are caused by the interaction between the rolling tire and the road surface. The tread block is the only tire component which is directly in contact with the cleft road surface texture and therefore of special interest. The contact due to the rough surface leads to complex contact phenomena e.g. friction characteristics depending on normal contact pressure and relative velocity, non-linear contact stiness and wear eects changing the tread block geometry and in hence the local contact forces. These contact phenomena strongly influence the dynamical behaviour of the tread block and the whole tire. A modular model based on a modal reduction method will be presented to investigate the tread block dynamics under consideration of the local friction characteristic, the non-linear contact stiness and wear which are also analyzed experimentally on a concrete road surface to identify the model parameters.