Abstract

Mechanical losses in rubber compounds per strain cycle are shown to be considerably greater under pulse loading, which simulates tire usage, than under sinusoidal loading. A method is suggested for using data obtained by ordinary laboratory techniques to calculate losses that would occur in an arbitrary anharmonic mode. Some data are given to show how such mechanical losses depend on formulations and processing factors of the rubber. Methods are then discussed for obtaining proper laboratory data on dynamic properties for use in optimizing formulations of tire rubbers.