Chapter 7- Forces in Beams
Beams are like frames. If you recall when we analyzed frames in statics all we did was find the reactions at the support of pins, the same was true with machines. Internally there is a lot going on, beams aren't simply in tension or compression like truss members.
For a two-dimensional beam they typically have 3 things going on inside them: an axial force (although this is normally zero), a shear force, and a moment (sometimes referred to a bending moment).