Truck Tire Groove Cracking Theory and Practice

TLDR: In this paper, an empirical method is described which enables the energy to be estimated for a tire groove from measurement of the amount by which a crack opens under stress, and the method also enables the strain to be determined and can be applied to any stressed article.

Abstract: The work described has aimed at clarifying the mechanism of groove cracking in tires. Basic studies of the fracture mechanics of rubber have shown that the rate of growth of a crack is independent of sample shape and type of deformation when it is expressed in terms of the available elastic energy. An empirical method is described which enables the energy to be estimated for a tire groove from measurement of the amount by which a crack opens under stress. The method also enables the strain to be determined and can, in principle, be applied to any stressed article. Using this approach and the crack growth characteristics of the tread rubber, the rate of growth of groove cracks in a tire can be predicted. Satisfactory quantitative agreement is found between observed and predicted behavior suggesting that the mechanism has been correctly identified. The work indicates relevant design factors and material properties and enables an appropriate laboratory test for groove cracking resistance to be defined.