Stress-Strain Relations and Solutions for a Kelvin Solid

Differential Stress-Strain Relations and Solutions for a Kelvin Solid 

The Kelvin model is also frequently used to describe the phenomena of creep. Recall the Kelvin solid from Fig. 3.21. 

There is no initial elasticity as the damper only allows the spring to move slowly with time. Also, the Kelvin model is not useful in understanding the relaxation response of materials because the damper does not allow the spring to move instantaneously. 

for a very large time, a constant strain state, e , is achieved 

The retardation time, x, is defined as the time required for the strain to come within 1/e of its asymptotic value. That is, Eq. 3.40 becomes, 

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