Viscoelasticity analysis question

[sarkamato]

Let's say I have a maxwell body, with a behavior of exponential decay in stress relaxation test. Let's say that that a graph obtained from multiple tests of high molecular polyethleyne.

my question is if I took this graph and drew a tangent line (derivative) about a point what will this represent?
I thought about it, and I think its either the modulus or the dashpot viscosity. based on the formula derivation stress = Ke^((-E/n)t)
where
ds/dt = -E(1/n)*s s = stress

if its not a modulus, then how would I obtain the modulus?

 

[Navin A S]

The tangent line you draw from the graph will represent the rate of change of the stress over time, or the derivative of the stress with respect to time. This information can be used to calculate the modulus by using the equation: Modulus = Stress/Strain. In this case, the modulus would be equal to the slope of the tangent line divided by the strain value at that point.