Modelling Intrinsic Sources of Nonuniformity and Their Interplay

ABSTRACT Uniformity characteristics of a tire are a direct reflection of the quality of the manufacturing process that produced it. This is realized in the homogeneity of its different stiffnesses and dimensions around the tire. Evidently, this is the most closely monitored aspect for consistency, from the original equipment manufacturers and manufacturers alike, and the requirement for tighter acceptance criteria is ever-increasing. However, the authors endeavor to find the lowest theoretical level for the same, given the intrinsic sources. The current study attempts to establish a framework to investigate the effect of the most pronounced factors individually, their interplay, and how their combined effect can be minimized. The present work on a 185/65R15 passenger car radial tire attempts to determine the effect of variable pitch sequencing as well as splicing and tread runout for a patterned tire on radial force variation (RFV). The study is carried out using finite element simulation for it presents the opportunity to study the individual effects systemically and economically. The study reveals a nearly 20% of the specification limit can be due to tread pattern sequence while the effect of the overlapping components may vary by 10% of the same limit. The study also suggests spotting arrangements to target and avoid. Finally, the authors present a method, captured in a MATLAB program that benefits the tire designer, plant engineer, and quality control manager.