The tensile stress-strain curve of a certain material is best represented by a satu- ration model, σ = σ o[1 - exp(- Aε)].
A. Derive an expression for the true strain at maximum load in terms of the constants A and σ o.
B. In a tension test, the maximum load occurred at an engineering strain of e = 21% and the tensile strength was 350 MPa.
Determine the values of the constants A and σ o for the material. [Remember that the tensile strength is the maximum engineering stress.]