2.2. Moment Diagram

Establish the M and x axes and plot the values of the moment at the ends of the beam.

• Since the slope of the moment diagram at any point is equal to the intensity of the shear at the point.

• At the point where the shear is zero, and therefore this may be a point of maximum or minimum moment.

• If the numerical value of the moment is to be determined at a point, one can find this value either by using the method of

sections as discussed befor or by using Eq:

which states that the change in the moment is equal to the area under the shear diagram.

• Since V(x) is integrated to obtain M, if V(x) is a curve of degree n, then M(x) will be a curve of degree For example, if V(x) is linear, M(x) will be parabolic.

Exemple

Draw the shear and moment diagrams for the beam in Figure (a) Draw the shear and moment diagrams for the beam in Figure (a)