QUESTION $3$: ENERGY METHODS:

TRUSSES $($SDS$).$

Determine the horizontal and vertical

displacements at joints $B$ for the

statically determinate pinjointed roof

truss shown. Use the Castigliano's

theorem method. The sizes of the

member $AB=BC=1000m{m}^2,$

$AD=CD=750m{m}^2$ and $BD=500m{m}^2,E=$

$14$ GPa for all members.