OPTYRE - a new technology for tire monitoring: evidence of contact patch phenomena

The present paper contains the description of a new technology for optical strain measurements in rolling tires. The apparatus is based on the use of Fiber Bragg Gratings sensors and light spectrum analyzer. With the help of a new analytical model, describing the tire strain during its revolution, the experiments permit, for the first time, to provide evidence of the transition along the contact patch between the grip and the slip regions. Moreover, the contact patch is identified and the experimental evidence suggests that the existing methods provide underestimated lengths.