Abstract

Tire vibrations were studied by applying an oscillatory load to bias, belted bias, and radial ply tires in the radial, lateral, and circumferential directions. Resonant frequencies were noted in each type of tire and the corresponding mode shapes observed with both real time and time average holography. The importance of tire vibrations in affecting vehicle ride is noted and the variables affecting these vibrations discussed.

Abstract

Examination of heat generation in an earthmover tire traversing rigid terrain indicates that almost all heat originates in the tire bulk; heat generated in the contact area is small and can be neglected. Modeling of equilibrium bulk heat requires using the same compound for model and prototype, keeping both tires geometrically similar, and running them at constant speed long enough to reach equilibrium temperature. Then, three model rules apply; one allows for geometrical distortion of cord arrangement in static loading, and the others impose similar mechanisms of heat generation and dissipation on the model and prototype. The effect of cord distortion on heat generation is unknown, however, and has to be assessed experimentally.

Preliminary tests indicate that the model rules of heat generation are basically correct. Problems associated with stress distortion (due to cord distortion), heat convection, and inflation pressure buildup (due to heat buildup) remain. Self‐modeling tests on the same tire, and scale model tests with geometrically similar tires are recommended.

Abstract

The theoretical basis for inflated tire calculations is explained, and models of the tire are developed that exhibit a high degree of accuracy. After establishing the fundamental equations common to the various models, the simplest case, a net of inextensible cords, is treated. The effects of cord extension and angular distributions different from the simple cosine law are then considered. It is shown that for each model it is convenient to proceed to a particular form of the fundamental formula in order to simplify the calculations and to clarify the influence of the various parameters. These models are of value for conventional tires; in the case of radial tires it is only possible to study the part of the carcass away from the belted zone.