Using the data in Problem 6.28 and Equations 6.15, 6.16, and 6.18a, generate a true stress?true strain plot for aluminum. Equation 6.18a becomes invalid past the point at which necking begins; therefore, measured diameters are given below for the last four data points, which should be used in true stress computations.

Load Length Diame ter N. in. in. 46,100 10,400 56.896 2.240 11.71 0.461 2.270 42,400 10,100 57.658 10.95 0.431 9,600 0.418 42,600 58.420 2.300 10.62 2.330 9.40 36,400 8,200 59.182 0.370 (6.15) OT A; (6.16) 7 = In (6.18a) or = o(1 + )