# Indoor Measurement of Contact Stress Distributions for a Slick Tyre at Low Speed

## TL;DR

This paper studies how different tyre settings affect contact stress distributions for motorsport slick tyres measured indoors at low speeds.

## Contribution

A novel complex transducer with a transversal array of sensing pins was used to measure triaxial contact stress distributions for slick tyres under various conditions.

## Key findings

- Triaxial contact stress distributions were measured using a transversal array of 30 sensing pins.
- Stress distributions were analyzed in 2D graphs, surfaces, and color maps under varying tyre parameters.
- Local extreme stress values were identified and linked to tyre functional parameters.

## Abstract

What are the main findings?
Complex transducer with a transversal array of sensing pins on the entire footprint width.Experimental programme with different values of tyre inflation pressure, vertical load, camber angle and toe angle.

Complex transducer with a transversal array of sensing pins on the entire footprint width.

Experimental programme with different values of tyre inflation pressure, vertical load, camber angle and toe angle.

What is the implication of the main finding?
Tyra–road contact stress measured indoors at low speed.Measurements performed for motorsport slick tyres at low longitudinal speed in free-rolling conditions.

Tyra–road contact stress measured indoors at low speed.

Measurements performed for motorsport slick tyres at low longitudinal speed in free-rolling conditions.

The paper presents results of experimental research on tyre–road contact stress distributions, measured indoors for a motorsport slick tyre. The triaxial contact stress distributions have been measured using the complex transducer containing a transversal array of 30 sensing pins covering the entire contact patch width. Wheel displacement in the longitudinal direction was measured using a rotary encoder. The parameters allocated for the experimental programme have included different values of tyre inflation pressure, vertical load, camber angle and toe angle. All measurements were performed at low longitudinal speed in free-rolling conditions. The influence of tyre functional parameters on the contact patch shape and size has been discussed. The stress distributions on each orthogonal direction are presented in multiple formats, such as 2D graphs in which the curves show the stresses measured by each sensing element versus contact length; surfaces with stress values plotted as vertical coordinates versus contact patch length and width; and colour maps for stress distributions and orientations of shear stress vectors. The effects of different parameter types and values on stress distributions have been emphasised and analysed. Furthermore, the magnitude and position of local extreme values for each stress distribution have been investigated with respect to the above-mentioned tyre functional parameters.