A substance exhibiting characteristics consistent with a standard linear solid undergoes the strain variations depicted in the upper graph. The corresponding stress reaction is illustrated in the lower graph.

A. Represent the strain pattern depicted in the upper graph by expressing it as a composite of unit-step functions. Display your calculations. (10 points)

B. Utilize the supplied graphs to approximate the complete set of model parameters necessary for defining the viscoelastic properties of the material. Provide a detailed explanation of your calculations, and include the appropriate units. 

 

Strain, E 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 Stress, g(t) (kPa) 0 25 20 15 10 5 -5 -10 0 hammb 2 2 4 4 6 6 8 10 Time, t (s) 10 12 12 14 14 16 16 18 20 Time, t (s) 18