Problem $1$:

A three$-$member truss structure is shown in Figure P$3-4$ with corre$-$

sponding node and element numbering for a finite element model.

Elements $1$ and $2$ are aluminum, and element $3$ is steel. The cross

section areas are $1\mathrm{.}5$ sq $.$ in$.$ for element $1$ and $1\mathrm{.}0$ sq $.$ in$.$ for

elements $2$ and $3.$ Determine the displacement of node $2$ and the

stresses in each member. Solve$-$by$-$use$-$ef$-$a$-$eomputer$-$pregram$-$and$-$

by hand calculation. Report in a neat and concise informal engi$-$

neering communication. Please include the hand calculated

structure stiffness matrix in its full $(8$ by $8)$ and reduced form.