Development of field test procedure to assess force performances of used tires

Abstract

Based on United Nation Economic Commission for Europe (UNECE) regulations, there are no existing standard procedures to identify the force performance of used tire which can be physically degraded by time. In vehicle safety, these tire forces in lateral and longitudinal directions are the key factors to response the driver decision during the brake application and maneuver conditions. Therefore, the objective of this research is to develop the used tire performances based on three vehicle testing standards such as brake test, steady-state circular test and severe lane-change test respectively. To assess the tire force performances, two tire categories which are used in those tests with the driving and pedal robot for the sedan vehicle are classified as new tires from 2018 and used tires from 2015, 2014, 2013. To identify tire force performances, various indicators for each test are determined. For example, the standard brake test from UNECE R13H is used to investigate tire friction force in the longitudinal direction. The severe lane-change manoeuvre and steady state circular tests are used to identify the lateral tire force from ISO 3888-2 and ISO 4138 respectively. As a result, it can be concluded that the tire force performances from new and used tires are different based on various indicators.