Abstract
Temperature change of polycarbonates under tensile loads was measured, respectively in static tension and in pulsating tension. In the former case, the specimen began to rise in temperature when viscoelastic strain became appreciable on the stress-strain diagram. The rise θV could be formulated as a function of the viscoelastic strain εV, In fatigue tests, the average temperature began to rise immediately after the decrease due to thermoelastic effect. The amount of the heat generation, α, was constant for each cycle throughout the fatigue process and has a relation to the fatigue life, Nf, where a is another adjustable constant. From the rheological aspect of dissipation energy, the equation is transformed to a relation between the viscoelastic strain and the fatigue life as which is similar to the one for metals given by Coffin and Manson.
The temperature rise in fatigue was also related to the viscoelastic strain. The relation was of the same form as in static tension but with value of the factor one order less.
