Experimental and Numerical Simulation of the Dynamic Frictional Contact between an Aircraft Tire Rubber and a Rough Surface

Iulian Rosu,Frédéric Lebon,Hagen Lind,Matthias Wangenheim,Hélène Elias-Birembaux

doi:10.3390/lubricants4030029

Abstract

This paper presents a numerical simulation of an aircraft tire in contact with a rough surface using a variable friction coefficient dependent on temperature and contact pressure. A sliding facility was used in order to evaluate this dependence of the friction coefficient. The temperature diffusion throughout the tire cross-section was measured by means of thermocouples. Both frictional heating and temperature diffusion were compared to numerical two- and three- dimensional simulations. An adequate temperature prediction could be obtained. In future simulations, wear should be taken into account in order to have a more accurate simulation especially in the case of high pressures and slipping velocities. A 3D finite element model for a rolling tire at a velocity of 37.79 knots (19.44 m/s) and in a cornering phase was investigated using a variable friction coefficient dependent on temperature and pressure. The numerical simulation tended to predict the temperature of the tire tread after a few seconds of rolling in skidding position, the temperature of the contact zone increases to 140 °C. Further investigations must be carried out in order to obtain the evolution of the temperature observed experimentally. The authors would like to point out that for confidentiality reasons, certain numerical data could not be revealed.

Highlights

Aircraft tires are subject to very high performance requirements when providing directional control and braking during the maneuvering of the airplane on the ground
Further investigations must be carried out in order to obtain the same evolution of the temperature observed experimentally
A numerical simulation of an aircraft tire in contact with a rough surface, using a test conditions, to the thermal conductivity of the runway surface and to the inelastic deformation, one of the most important mechanisms which leads to self-heating

Summary

Introduction

Aircraft tires are subject to very high performance requirements when providing directional control and braking during the maneuvering of the airplane on the ground. The tires must support the aircraft’s weight, and transmit acceleration and braking forces to the runway surface, and supply the forces necessary for the directional control of the aircraft [1]. It is well known that the directional capacity of an aircraft is measured by the friction coefficient [2]; this is the measurement of the contact area forces as a fraction of the aircraft’s weight. Many other studies investigated the interaction of various phenomena in the contact area, with the friction coefficient [6,7,8]. The normalized tire friction coefficient μ = Fy /Fz is used in most tire friction models, where Fy is the tangential friction force at the tire/runway interface and Fz is the vertical loading on the tire (Figure 1). Μ is the sliding friction coefficient, Lubricants 2016, 4, 29; doi:10.3390/lubricants4030029 www.mdpi.com/journal/lubricants

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