Stress-Strain Behavior at Constant Rate of Deformation

Stress-Strain Behavior at Constant Rate of Deformation 

Examination of the stress as a function of time during retraction at constant strain rate following extension, and in particular for several successive cycles of elongation and retraction, reveals some further complications. The stresses during retraction are smaller than would be calculated on the basis of equation 8, and are smaller during extension in the second cycle than in the first. (This phenomenon, known as the Mullins effect, is particularly evident in filled rubbers, but appears also in the absenee of filler. ) 

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