Question

Figure 9.11 shows the strain-stress curve for a given material. What are (a) Young’s modulus and (b) approximate yield strength for this material?

Answer 1

The stress strain curve is shown in the figure below,

(a)

Young’s modulus is given by the equation,

Y= stress strain

The stress and strain within the limit of proportionality is 150× 10 6  N/ m 2 and 0.002 respectively.

Substituting the values in the above expression, we get:

Y= 150× 10 6  N/ m 2 0.002 =7.5× 10 10  N/ m 2

(b)

The yield strength of the material is the maximum value of stress after which there is permanent deformation..

The maximum value of yield strength from the given graph is approximately 3× 10 8  N/ m 2 .