Sciences & Société
Soutenance de thèse : Efoé Rodrigue WALLACE
On the rolling contact between multi-layered bodies, application to tire-pavement modelling
Doctorant : Efoé Rodrigue WALLACE
Laboratoire INSA : LaMCoS
Ecole doctorale : ED162 : Mécanique, Energétique, Génie Civil, Acoustique de Lyon
The present work concerns the development of a dimensioning tool for pavement design. In order to better understand the degradations observed at their surface, a modelling study is carried out.
This modelling task has been performed with contact mechanics tools. Particularly, a semi- analytical model has been developed, based on Fast Fourier Transform (FFT) and Conjugate Gradient Method (CGM) algorithms. With view to achieve a more realistic modelling of the tire-pavement contact, the focus has been put on three aspects.
Firstly, the multi-layered aspect of the pavement has been considered. Using the Papkovich- Neuber potentials, the influence coefficients have been found in the Fourier frequency domain. A numerical inversion using FFT algorithms allows to find them in the space domain.
Secondly, the viscoelastic behaviour of asphaltic materials, used in roads construction, has been accounted. To this aim, an Elastic/Viscoelastic correspondence has been proposed. This correspondence imposes to recalculate the influence coefficients at every time step. However, the simulations remain straight and fast. In addition, the proposed correspondence is exact in some cases (especially in steady-state regime); and it is an approximation in the other cases where the committed error has been shown to be marginal.
Thirdly, the effects of the tangential forces have been integrated to the rolling contact. The goal is that the present tool can simulate acceleration, braking, turnaround, etc. cases where tangential forces and/or moment are applied on the wheel in addition to the normal force. This tractive rolling contact has been solved between elastically dissimilar bodies submitted to tangential forces and a spinning moment.
All these aspects, introduced together in the model, have allowed to simulate realistic cases of rolling contact between the tire and the pavement. From examples such as acceleration, turnaround and drift, it has been proven that the tangential forces increase significantly the overall stresses.
Amphithéâtre Emilie du Châtelet (bibliothèque Marie Curie) - (Villeurbanne)