Tensile Stress Relaxation following Deformation at Constant Strain Rate

Tensile Stress Relaxation following Deformation at Constant Strain Rate 

If a sample is stretched at constant strain rate to a strain c at time t, and then the stress is allowed to relax at constant strain, the course of stress relaxation is given by linear viscoelasticity as 

However, for / i, equation 1 reduces to equation 2, thus justifying the assumption implicit in experimental procedures that rapid loading is equivalent to instantaneous for practical purposes. Equation 1 has been discussed by Meissner and Smith in connection with combining deformation at constant strain rate with subsequent relaxation to obtain viscoelastic information, as mentioned in Section FI of Chapter 3. 

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