Problem # p005

Axial Stresses and Strains

In the figure below the beam A-B-C is rigid and is originally installed exactly horizontally. Then the load P is applied. The points at which the rods 1 and 2 are mounted at the ceiling are immobile.


  1. After sketching the Free Body Diagram and obtaining the equilibrium inspect your equations. Is this problem statically determinate or indeterminate ?

  2. By how much does the vertical position of point C change due to the load P ?

NOTE : The angle between beam ABC and the horizontal will be only a few degrees leaving the horizontal distance between the points A, B, and C practically unchanged.
    For both cables :
Length L = 4 m;     Cross-section A = 5 cm2
Modulus of elasticity E = 200 GPa

Horizontal distances :
a = 3 m , b = 5 m

Load P = 60 kN