[ANSWERED] For the rigid stairway frame shown in Figure P5–3, determine (1) the displacements at node 2, (2)…

For the rigid stairway frame shown in Figure P5–3, determine
(1) the displacements at node 2, (2) the support reactions, and (3) the local
nodal forces acting on each element. Draw the bending moment diagram for the
whole frame. Remember that the angle between elements 1 and 2 is preserved as
deformation takes place; similarly for the angle between elements 2 and 3.
Furthermore, owing to symmetry, u
2
= u
3
, v
2
=
v
3
, and
2
=
3
.
What size A36 steel channel section would be needed to keep the allowable
bending stress less than two-thirds of the yield stress? (For A36 steel, the
yield stress is 36,000 psi.)