Stress Relaxation from Sudden Strains of Large Amplitude

Stress Relaxation from Sudden Strains of Large Amplitude (361) 

For shear strains of sufficiently small amplitude, the response is linear and the shear stress is governed by the stress relaxation modulus  

For shear strains greater than approximately 2 the ratio cr(r)/ 0 for a concentrated polystyrene solution was reduced at all observable times. For the large strains, relaxation proceeded more rapidly at short times, but at longer times the residua] stress decayed with about the same time dependence as that in the linear viscoelastic region. 

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