The effects of tyre material and structure properties on relaxation length using finite element method

This study investigates the influence of tyre structural layup and material properties on the relaxation length of a rolling tyre using finite element analysis. Relaxation length for rolling tyre under different operating conditions has been studied recently. However, the effects of tyre structural layup and material properties on relaxation length were ignored. In this present work, a finite element (FE) tyre model was built based on the material and geometry properties obtained from measurements of the tyre provided by a vehicle company. Rather than the common method (steady state rolling analysis) used for cornering behaviour simulations, ABAQUS/Explicit program was used for prediction of the cornering performance and relaxation length for a constant slip angle of the rolling tyre. Two different steer inputs were applied to the rolling tyre in terms of slip angle variation, namely step input and ramp input. The effects of various factors, including cross-section area, spacing, crown angle and strength of the tyre reinforcement cords, on relaxation length of the rolling tyre were investigated by numerical experiments using the design of experiment (DOE) method. [Display omitted] •The structural layup of the tyre has been characterised using image processing techniques•A combination of material tests and material modelling in Abaqus was used to characterise rubber properties•Time domain simulation in Abaqus/Explicit was used to obtain relaxation length for different target slip angles•The effects of various tyre structure design factors on relaxation length have been characterised•The tyre carcass reinforcement properties are the factors which control the relaxation length