A material that behaves like a Maxwell viscoelastic model is subjected to the strain history plotted below $($top$).$ The

resulting stress response is also plotted $($bottom$).$

A$.$ Express the strain history shown in the top plot as a combination of unit$-$step functions.

B$.$ Use the plots provided to estimate all of the model parameters required to fully$-$define the material's

viscoelastic behavior. Show your work. Be sure to box your final answers and include the correct units!

C$.$ Using the estimated material parameters from $($b$),$ plot the stress response for a strain history given by:

epsilon$($t$)=-1\mathrm{.}5$ H$($t$-2)+1\mathrm{.}5$ H$($t$-5)$