Method for improving tread noise of a tire by relative rotation of a rib, and simulating the tread noise effected thereof

摘要

A method is disclosed for evaluating the level of objectionable noise associated with the operation of a tire by virtue of its tread contacting a road surface, which comprises digitizing the tread de­sign on a coordinate system so as to define load-supporting portions of the tread in contact with the pavement, and distinguish them in binary form from those portions of the tread which are not in con­tact, as multiple matrix elements; defining a generally arcuate pro­file of a leading or trailing edge of a footprint of the tread by fitting an equation to the edge; sequentially performing the time ensemble summation, of the noise produced by each matrix element, over ev­ery matrix element on the entire circumferential surface; converting the sequence of summation to a periodic analog signal; converting the analog signal to a sound; and aurally evaluating the sound. In a simplified case 0's and 1's along at least one footprint edge are sequentially summed around the circumference of the tire. The system requires only a means for digitizing the tread pattern, a computer to perform the necessary manipulations of data, and a means to convert a digital signal to an analog signal. Having sub­jectively chosen a tread pattern deemed to have an acceptable noise level, ribs are then relatively rotated one with respect to another to obtain an improved level of tread noise.