Problem $1$

The truss shown below has a pin support at A and roller support at D$.$ All members have elastic modulus E$=29000$ksi. All members have cross$-$sectional area, A$=12$in$^(2),$ except for the members on the top chord $,$ and EF$,$ which have A$=18$in$^(2).$ There is a load at joint C and a support settlement at D$.$

Question $1$

Use virtual work to compute u$\_($By$),$ the vertical deflection of joint B$.$

Answer:

u$\_($By$)=0\mathrm{.}22618$ inch darr

Question $2$

Use virtual work to compute u$\_($Cy$),$ the vertical deflection of joint C$.$

u$\_($Cy$)=0\mathrm{.}45153$ inch darr

Question $3$

Explain why computing the deflection at C was far easier than computing the deflection at B$.$