How does heat generation affect the cut and chip wear of rubber?

Abstract

Tire wear is a fracture process that has a decisive impact on tire life and on the environment. When a tire rolls, a heating process occurs due to friction caused by the viscoelastic rubber sliding over uneven road. This process occurs globally in the contact patch area and locally around the asperity tips, heating the tread and transferring heat to the surrounding material. On roads with a good quality pavement, the stress, and therefore the heat, is evenly distributed throughout the rubber material of the tire, which has a direct effect on fatigue wear. In contrast, unevenly distributed stress, and therefore heat, is generated in the tread when the tire rolls and slides over sharp asperities in rough terrain. This leads to very pronounced, unstable fracture processes that cause unevenly distributed wear, known as cut and chip (CC). The extent of heat generation or temperature evolution and its effect on CC wear have not yet been investigated and described in scientific publications. Therefore, this study firstly presents the detailed characterization of the influence of temperature development on the CC wear of a styrene-butadiene rubber, which commonly is used in treads of consumer tires. The investigations were carried out using the unique instrumented cut and chip technique in combination with a high-speed thermography.