1. [20pts] A tensile specimen of initial length 120 mm and cross-sectional area 30 mm? is subjected to an axial load that produces the true stress - true strain curve

shown (Figure 1).The logarithmic plot of true stress - true strain is also shown (Figure 2) for the region beyond the yield point. (a) Describe the true stress-true strain behavior by determining the coefficients (0, and n) in the equation: SIGMA= SIGMA EPSILONX (b) Determine the length of the specimen when the true strain is 0.4. (c) Determine the cross-sectional area when the true strain is 0.08. (d) Determine the tensile strength (true and engineering) of the specimen.