High-speed 3D digital image correlation for rolling deformation of a tire sidewall and measuring dynamic contact patch length.

Abstract

Tires play a vital role in a vehicle's operational stability, comfort, and security. However, due to the influence of test equipment and tire operating conditions, the perception of rolling tire characteristics is still in the stage of gradual improvement, especially the analysis of sidewall rolling deformation and dynamic contact peculiarities of tires/road interactions, which has restricted the analysis of rolling energy dissipation and the accurate observation of tire forces. In this paper, the high-speed stereo-vision system was created by high-speed cameras, and the relative rigid and flexible displacement, strain, and trajectory trend of marker points and the real-time global displacement field of the sidewall during the tire-rolling cycle were acquired utilizing the improved digital image correlation algorithm under different rolling velocities. Meanwhile, the periodic dissipation of the strain concentration region was observed, and the phenomenon of strain resonance appeared at the overlap of the periods. The relative flexibility strain and shear strain of the marker point were obtained on the plane element, which resulted in the relative flexibility major principle strain of the plane element, and then it achieved recognition of the leading and trailing points of the contact patch and the accurate measurement of dynamic contact patch length.