Evaluate elongation of bar of varying cross section:

How you evaluate elongation of bar of varying cross section:?

Sol.: Take bar made up of different lengths and which is having different cross sections as shown in the figure given below.

For this type of bar, the following conditions apply:

(i) Each section is subjected to same external pull or push

(ii) Total change in length is equal to sum of changes of individual lengths

That is:

P₁ = P₂  = P₃  = P as       H = 0  &       V = 0 and

If bar segments are made of same material, then in that particular case