Chapter 2, Problem 2.1Q

To determine

Whether the percentage elongations of materials are calculated on the basis of Figure 2.6 or not and also explain the reason

Answer to Problem 2.1Q

The percentage elongations of materials cannot be calculated on the basis of Figure 2.6.

Explanation of Solution

Given:

The Figure 2.6 represents the graph between true strain and true stress.

Concept used:

Write the expression for percentage elongation.

  $E=\left(\frac{l_f-l_a}{l_a}\right)\times 100$ .......... (1)

Here, E is percentage elongation, $l_f$ is fracture length and $l_a$ is the initial length.

Calculation:

From Figure 2.6 the value of fracture strain and necking strain can be calculated but the original gage length cannot be calculated from Figure 2.6.

Equation (1) represented that elongation is function of the gage length, and gage length cannot be calculated from Figure 2.6. Therefore, the percentage elongations of materials cannot be calculated by Figure 2.6.

Conclusion:

Thus, the percentage elongations of materials cannot be calculated on the basis of Figure 2.6.