2-4.  The rod is subject to forces P and Q, which follow the distribution  kN and  kN. Determine the distributions of the displacements of point B and point A given  GPa,  GPa,  mm, and  mm. Assume P and Q are independent.

Fig. 2.4

Solution

Solve for the areas of each section.

 m²

m²

Find the displacement of point B in terms of Q.

Using the equation above, solve for  and .

 m = 1.2 mm

 m = 0.0745 mm

Thus

 mm                                               Ans.

Find the displacement of point A in terms of P and Q.

Using the equation above, solve for  and .

= 0.0027 m = 2.7 mm

=  m = 0.13 mm

Thus

mm                                                   Ans.