MecMovies 4.0 : M5.8: Rigid Bar with Opposing Members

The figure shows a rigid bar A B C D pinned at A and supported by vertical bars at B and C. The vertical bar at B is labeled 1 and pinned at its top end and the vertical bar at C is labeled 2 and pinned at its bottom end. The separation between A and B is 760 millimeters. The separation between B and C is 760 millimeters and the separation between C and D is 120 millimeters. A load P directed vertically downwards is applied at D.

A pin-connected structure is loaded and supported as shown. Member $ABCD$ is a rigid bar that is horizontal before the load $P$ is applied.

Members $(1)$ and $(2)$ are aluminum $(E = 70 GPa)$ with cross-sectional areas of $A_{1} = A_{2} = 160 {mm}^{2}$ . Member $(1)$ is $900 mm$ in length, and member $(2)$ is $1, 250 mm$ . A load of $P = 35 kN$ is applied to the structure at $D$ .

a) Determine the axial forces in members $(1)$ and $(2)$ .

b) Compute the normal stresses in members $(1)$ and $(2)$ .

c) Compute the downward deflection of the rigid bar at $D$ .