Estimation of tyre-road contact pressure distribution based on nonlinear finite element analysis

Abstract

A methodology to estimate the tyre-road contact pressure distribution in x-z plane as functions of inflation pressure and normal load for a truck tyre is proposed. The modelling process is based on the 3D pressure fields obtained through the non-linear static stress analysis of a finite element (FE) tyre model, which considers the structural geometry, the anistropic material properties of the multiple layers and the nearly-incompressible property of the tread rubber block. The 3D pressure fields are analysed to derive 2D contact pressure distribution using the equivalent work as the basis. Curve fitting techniques are applied to derive a polynomial function to describe the contact pressure distribution as function of the normal load, inflation pressure and co-ordinate along the contact patch. The polynomial function is then applied to derive an estimate of the contact patch length and contact pressure distribution corresponding to specific values of resultant tyre force and inflation pressure. The validity of the estimated contact pressure is compared with that obtained from the FE tyre model. It is concluded that the proposed polynomial is capable of predicting the 2D contact pressure distributions in the longitudinal direction when the inflation pressure and the normal load of the tyre are known. The proposed polynomial function and the methodology, which are mostly in conjunction with simplified point-contact tyre model, can thus be applied to study the distributed pavement loads due to truck tyres.