This informative construction video briefly explains how to determine equation for shear force & bending moment as well as how to sketchup their diagrams.
The shear force at a segment of a beam denotes the force that shears off the section and is procured like the algebraic sum of all forces together with the reactions functioning normal to the axis of the beam both to the left or right of the beam. As the beam is a inflexible structure, the force will be transmitted internally all along the beam. This internal force is called shear force.
Shear and bending moment diagrams belong to analytical tools applied in combination with structural analysis to facilitate accomplishing structural design by finding out the value of shear force and bending moment at a specified point of a structural element like a beam. These diagrams are used to define the type, size, and material of a structural member efficiently in a structure with the purpose of supporting a specified set of loads devoid of structural failure. Shear and moment diagrams are also useful to find out the deflection of a beam easily by applying either the moment area method or the conjugate beam method.