Abstract
Our previous report has theoretically shown that the wave velocity in the circumferential direction of the tyre tread is a function of its wave length, if the bending stiffness of the tread and the effect of the elastic foundation of the side-walls of the tyre are taken in consideration, and that the minimum velocity with respect to the wave length means the critical standingwave velocity. When the impact load is given at a point of the tread, the compound wave motion composed of many single wave motions is produced. From this point of view it is most important to devise to measure conveniently the minimum wave velocity, which means the critical speed.
Thus, the method to measure the minimum velocity by using the time-counter device is proposed. This device is most conveniently available when lateral accelations of the tread are used as the imputs of the start-trigger and the stop-trigger of the time-counter.
The statical test method to check the standingwave phenomenon was proposed in the previous paper and to prove this analytical results, the experimental results of the statical test by concentrated load at a point of the tread and the comparison with the actual data of the drum tests are explained with good agreement.
