In a typical tension test a dog bone shaped specimen is pulled in a machine. During the test, the force F needed to pull the specimen and the length 7. of a gauge section are measured. This data is used for plotting a stress-strain diagram of the material. Two definitions, engineering and true, exist for stress and strain. The engineering stress σ and strain s, are defined by σ = F and &= L-Lo Lo where Lo and A are the initial gauge length and the initial cross-sectional area of the specimen, respectively. The true stress σ, and strain c, are defined by σ = and c₁ = In FL AoLo La The following are measurements of force and gauge length from a tension test with an aluminum specimen. The specimen has a round cross section with radius 6.4 mm (before the test). The initial gauge length is L₁ = 25 mm. Use the data to calculate and generate the engineering and true stress-strain curves, both on the same plot. Label the axes and label the curves. Units: When the force is measured in newtons (N), and the area is calculated in m², the unit of the stress is pascals (Pa). F(N) L (mm) F(N) 0 13,345 26,689 40,479 42,703 43,592 44,482 44,927 25 25.037 25.073 25.113 25.122 25.125 25.132 25.144 45,372 46,276 47,908 49,035 50,265 53,213 56,161 L (mm) 25.164 25.208 25.409 25.646 26.084 27.398 29.150