Section A Mechanical Properties 1 Identify the metal alloys

Section A: Mechanical Properties 1. Identify the metal (alloys) given by the following curves by computing their Young\'s and Shear modulus. Assume Poisson\'s ratios of: (a) v 0.31, and (b) v 0.33. (2 X 4 points) (a) Stress MPa) 0003 0013 002 0023 003 Strain

Solution

a)

Young\'s mod E = Stress / strain = 500*10⁶ / 0.005 = 1*10¹¹ Pa = 100 GPa

Shear mod G = E / [2*(1+v)] = 100 / [2*(1+0.31)] = 38.17 GPa

b)

Young\'s mod E = Stress / strain = 190*10⁶ / 0.003 = 6.33*10¹⁰ Pa = 63.33 GPa

Shear mod G = E / [2*(1+v)] = 63.33 / [2*(1+0.33)] = 23.8 GPa

c)

For yield strength, we draw a line parallel to the linear portion, starting from strain = 0.002

The intersection point will give yield strength.

For case a), we get Yield strength = 800 MPa

For case b), we get Yield strength = 320 MPa