Simple rotary dynamic testing machine
A N Gent; A N Gent; The British Rubber Producers' Research Association, Welwyn Garden City, Herts
Журнал:
British Journal of Applied Physics
Дата:
1960-04-01
Аннотация:
A test machine is described for determining the dynamic shear properties of rubber-like materials. It imposes a simple shear deformation, the direction of which is continuously rotated. The observations are easily made, and enable the dynamic shear modulus and damping factor to be determined rapidly; moreover, a relatively wide frequency range seems feasible. The instrument therefore appears suitable for general application. Measurements on a soft butyl rubber vulcanizate are described and compared with observations of free torsional oscillations. Good agreement is obtained.The test-piece is subjected to a rotating shear of constant amplitude, and hence the elastically-stored energy is held constant. The observed energy dissipation therefore confirms a hypothesis of Greenwood and Tabor, that dissipation may occur under such conditions, and indicates the limitations of the "hysteresis" concept that the dissipated energy is a constant fraction of the elastically-stored energy.
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