Chapter 6, Problem 6.37P

The following data were collected from a test specimen of cold-rolled and annealed brass. The specimen had an initial gage length $l_0$ of 35 mm and an intial crosssectional area $A_0$ of $10.5m{m}^2.$

(a) Plot the engineering stress strain curve and the true stress strain curve. Since the instantaneous cross- sectional area of the specimen is unknown past the point of necking, truncate the true stress true strain data at the point that corresponds to the ultimate tensile strength. Use of a software graphing package is recommended.

(b) Comment on the relative values of true stress strain and engineering stress strain during the elastic loading and prior to necking.

(c) If the true stress strain data were known past the point of necking, what might the curve look like?

(d) Calculate the 0.2% offset yield strength.

(c) Calculate the tensile strength.

(f) Calculate the elastic modulus using a linear fit to the appropriate data.