Volume 22, Issue 1 (January 1994)
A Computer Method of Analysis for Tire Wear Characterization, Identification, and Classification
A tire's rib profile before and after use can be determined by using two sets of measurements. These measurements are the tire runout values taken along the ribs before and after use. Superimposing these values over a circle with a predetermined constant radius that depends on the overall unloaded diameter of the tire as well as the maximum peak-to-peak runout value of the rib will result in the tire's rib profile. The difference of areas bounded between the rib's profile and the specified circle, before and after use, is a quantitative measure of tire wear along the rib. Therefore, it is the primary objective of this paper to outline a computer method of analysis, not only to generate the tire's rib profile before and after use, but also to provide a quantitative measure of rubber loss around the circumference of each tire rib. The significance of generating the profile is the ability to observe and locate the highest and lowest points of the tire along the rib and to inspect a tire for defects. This can be especially important for the tire manufacturers at their line of production. Among other important characteristics of this proposed method is the potential for predicting the wear nature of a tire rib, after use, by quantifying the loss of the rubber along the rib and by the process of decomposing each rib's profile into the sum of sinusoids with appropriate amplitudes and phase angles. This process of decomposition, which is commonly known as Fourier Analysis, can identify the harmonics with highest contributions to the shape of the profile. Harmonics with highest contributions play an important role in shaping the profile. Two tires with similar or close harmonic contents in their rib's profile, after use, can be classified as tires with identical wear pattern.