System for Strain-Distribution Visualization and Deformation Measurement of Tread Block under Fast-Rotating Tires

Although tread block deformation analysis is important, the deformation measurement is difficult because fast-rotating tires maintain a continuous contact with the road surface. Furthermore, capturing small displacements near the edge of tread blocks using a high-speed camera is difficult because of the particularly limited resolution. Additionally, the tread blocks being significantly deformed at the edge and susceptible to wear powder, the state change of the feature points, is highly probable. To overcome these problems, a system that obtains high-resolution images and measures the deformation of a fast-rotating body (tire) is proposed herein. The developed system captures the deformation behavior through intermittent imaging. To further measure the strain distribution, fine tracking markers are drawn on the tread block using a laser processing machine. The displacement of the marker is calculated using the particle mask correlation method. Measurements of a single-block tire with a rolling velocity of 50 km/h, using a 24M-pixel camera at 8,333-Hz pseudo-sampling frequency, have shown the ability of the developed system in capturing spatial resolutions and strain in the orders of 0.01 mm and 0.001, respectively. Furthermore, the strain distribution is comprehensively visualized, and a few deformation features of the tread block of a fast-rotating tire are shown.