Today's tread pattern design development is done independently from the tire body construction in order to achieve the best traction and uniform local wear performance. Nevertheless, a better understanding of the interaction between tread and body is necessary to improve the above mentioned properties. An identical tire has been investigated in four pattern steps, starting from a smooth tire, carving a block structure with longitudinal and lateral grooves, and finishing with additional sipes in the blocks. A new developed test stand, which is capable of measuring the stresses in the contact patch of the rolling tire in all directions with a resolution of 1 mm, is described. The local contact stresses of the investigated tread blocks are simulated by FEA using the measured loading conditions of the smooth tire. The results of this simulation are compared with measurements and mechanically interpreted.

For the tread pattern design, irregular wear of a tire is an essential development criterion. From a physical point of view, irregular wear results from frictional energy exerted onto the individual tread blocks. The local tangential stresses and movements are needed for the calculation of the local frictional energy. The measurement of slip is carried out optically using a line scan camera. The line scan camera enables measurements at real speeds (40 kmph) due to the camera's very high scan frequency. The picture acquirement is done through a glass window within a rotating drum of a test stand. With repeating roll over, the complete tire can be measured. Finally, stresses and slip are combined to frictional energy to be visualized in colored distribution onto the block surface as indication for local wear behavior. In order to validate the measurements and calculations, four different tread pattern with different stiffness due to tread design and compounding are investigated. For the validation, the block stiffness, frictional energy and irregular wear results are compared with each other.