A round bar is composed of three segments of the same material (Fig. P2.58).The diameter...

A round bar is composed of three segments of the same material (Fig. P2.58).The diameter is d for the lengths BC and DE and nd for length CD, where n is the ratio of the two diameters. Neglecting the stress concentrations, verify that the strain energy of the bar when subjected to axial load P is

Where  Compare the result for n=1 with those for n=1/2 and n=2.