Engr Help

Example - Internal Forces in Beams

The cantilever bent ABCD in the figure below is subjected to forces of P and Q at

point D. Determine the internal forces and moment in the beam at section B.

Strategy:

Step 1

Cut the beam at section B and construct a free body diagram as shown below.

Step 2

Apply the equations of equilibrium to determine the internal forces

and moment at section B.

Step 3

Identify the shear force, the axial force, and bending moment on a

positive x-face at section B.