PREDICTION AND SIMULATION OF TIRE PERFORMANCE CHARACTERISTICS BASED ON DEFORMATION INDEX CONCEPT

Abstract

ABSTRACT Tire performances such as wear, traction, and rolling resistance have been explained by the hysteretic energy loss of tread compounds under cyclic deformations. Loss factor, tan δ, is often used as the property responsible for energy loss. However, dynamic modulus is also reported to affect energy loss and tire performance. In this review, the modulus effect on energy loss is related to the deformation type through the deformation index. The index can be determined experimentally based on tire performance data or analytically through finite element analysis (FEA). Deformation indices of passenger tire rolling resistance, wet traction, and dry traction were determined experimentally based on tire tests. Using FEA, the energy losses and deformation indices were calculated for all elements of a rolling truck tire. The indices vary widely depending on where the element is located. Deformation indices are summarized on a tire component basis and converted into an Excel spreadsheet. The spreadsheet can be used to compute rolling resistance changes arising from component compound substitutions. The deformation index concept is applied to thermomechanical analysis, where it simplifies the fully coupled iterative FEA method into a noniterative computational method. The novelty of this method is in its application to transient thermomechanical problems. The method's simplicity and accuracy are demonstrated using examples.