Chapter 1, Problem 15E

The stepped bar shown in the figure is subjected to a force at the center. Use the finite element method to determine the displacement at the center and reactions RL and RR.

Assume: $E=\text{1}00\text{ GPa}$, the area of cross sections of the three portions shown are, respectively, $\text{1}{0}^{-\text{4}} {\text{m}}^{\text{2}},\text{ 2}\times \text{1}0{\text{ m}}^{\text{2}},\text{and 1}{0}^{-\text{4}}{\text{m}}^{\text{2}},$ and $F=\text{ 1}0,000\text{ N}$.