A Novel Nondestructive Procedure for Tire Tread Viscoelastic Characterization

Vehicle dynamics is largely influenced by the phenomena occurring in the tire-road interface, and a great portion of these phenomena is mainly conditioned by the viscoelastic properties of the tire tread compound. It is not surprising that the possibility of obtaining the viscoelastic response of a compound by means of a nondestructive procedure is a growing research topic that affects application fields ranging from monitoring of the material performance during its entire life cycle to the quantitative analysis of product quality and repeatability of production processes. In this article, a novel nondestructive procedure for the viscoelastic characterization of tire tread compound is proposed. A portable instrument, based on instrumented indentation, was designed and prototyped with the aim to allow a real-time assessment of moduli directly on site. The testing procedure adopted to perform the test on three different compounds was described. A signal-processing procedure was developed for the identification of compound stiffness and damping parameters from which viscoelastic moduli were estimated. The results were also compared with the DMA characterization showing the same relative ranking between the compounds with a different trend in temperature due to the amount of the tests' indentation depth.