8/3/2019 Abstract DefensePatrickSabiniarz 20110304

1/2

MODELLING THE VIBRATIONS ON A ROLLING TYRE

AND THEIR RELATION TO EXTERIOR AND INTERIOR

NOISE

PATRICK SABINIARZ

AKADEMISK AVHANDLING SOM FR AVLGGANDE AV TEKNOLOGIEDOKTORSEXAMEN VID CHALMERS TEKNISKA HGSKOLA FRSVARAS VID

OFFENTLIG DISPUTATION DEN 4 MARS 2011, KL. 10.00 I VG-SALEN, SVEN HULTINSGATA 6, 412 96 GTEBORG.

AVHANDLINGEN FRSVARAS P ENGELSKA. FAKULTETSOPPONENT R DR. INESLOPEZ ARTEGA, EINDHOVEN UNIVERSITY OF TECHNOLOGY.

INSTITUTIONEN FR BYGG- OCH MILJTEKNIKAVDELNINGEN FR TEKNISK AKUSTIK

CHALMERS TEKNISKA HGSKOLA412 96 GTEBORG

TELEFON 031-7721000

8/3/2019 Abstract DefensePatrickSabiniarz 20110304

2/2

MODELLING THE VIBRATIONS ON A ROLLING TYRE AND THEIR RELATION TO

EXTERIOR AND INTERIOR NOISE

Patrick Sabiniarz, 2011Department of Civil and Environmental EngineeringDivision of Applied Acoustics, Vibroacoustics GroupChalmers University of Technology

ISBN 978-91-7385-498-6Doktorsavhandlingar vid Chalmers Tekniska HgskolaNy serie nr 3179ISSN 0346-718X

Abstract

For most modern cars at normal driving speeds, tyre/road interaction is a major source to the exte-rior as well as interior vehicle noise. The interaction between a tyre and a road surface generatestyre structure vibrations, leading to sound radiation into the surrounding air, and to dynamicforces acting on the wheel hub. These forces are transmitted via the suspension system to the carbody, resulting in sound radiation into the passenger compartment. To reduce the exterior andinterior noise produced by rolling tyres, a deep understanding is required of the physics involvedin the excitation, transmission and radiation of tyre structure vibrations. The focus of this thesis is

on modelling of the vibrations on a rolling tyre and their relation to the sound radiation and theforces acting on the wheel hub. To be specific, state-of-the-art simulation tools, involving a tyremodel, tyre/road contact model and radiation model, are used to first identify the modes on a tyreresponsible for the radiation of sound during rolling. It was found that in the critical frequencyrange around 1000 Hz, where maximum radiation occurs, the radiation is mainly due to low-ordermodes. These modes are not the ones with the strongest excitation around 1 kHz, but have highenough radiation efficiency to dominate the sound radiation. The tyre model is then modified toincorporate the air-cavity and wheel, and used in connection with the contact model to simulatethe forces acting on a blocked hub during rolling. It was found that the transmission is stronglyinfluenced by three modes: the radial semi-rigid body mode on the tyre, the first mode inside the

fluid cavity and a wheel mode. Further, the spectra of the hub forces are concentrated to the low-frequency range (up to say 250 Hz). Finally, the thesis is also concerned with the extension of anexisting contact model for tyre/road interaction to encompass the tangential contact forces. Themodel is first validated towards an alternative contact formulation found in the literature. There-after, a minor parametric study is conducted to see the influence of rolling speed, road surfaceroughness and longitudinal slip ratio on the total radial and tangential contact force.