To calculate the modulus of elasticity for a material and the yield stress based on the stress-strain diagram.

Some materials do not have a well-defined yield point (Figure 1) . Instead, the stress-strain diagram gradually curves away from a linear response after a certain point. One method of defining the yield stress for such a material is the 0.2% offset method. The slope of the linear region is calculated. Then a parallel line is drawn starting at a strain of 0.002. The intersection of this line with the stress-strain curve defines the yield stress.

The following data were obtained using a tension testing machine with a sample at 20?C that had a circular cross section with diameter d0 = 12.5 mm and a gage length of L0 = 50 mm .

Load [kN]	Elongation [mm]
0.0	0.0
5.0	0.1
10.1	0.2
15.1	0.3
20.1	0.4
25.2	0.5
30.2	0.6
33.5	0.7
36.3	0.8
38.7	0.9
40.8	1.0
42.7	1.1
44.4	1.2
45.9	1.3
47.2	1.4
48.1	1.5

Part A Calculate the modulus of elasticity What is the modulus of elasticity of the material? Express your answer with appropriate units to three significant figures. ? E = Value Units Submit Hints My Answers Give Up Review Part Part B - Yield stress What is the yield stress for the material? Express your answer with appropriate units to two significant figures. M yield = Value Units Submit Hints My Answers Give Up Review Part ? Provide Feedback Continue