Shear Forces and Bending Moments:

In practice, all of beams are subjected to some kind of external loadings. As the beam is loaded, it deflects from its original location, which develops the moment & shear on the beam. Shear force (SF) & bending moment (BM) are extremely important in designing any type of beam because the beam is designed for maximum bending moment and also the shear reinforcement is provided for maximum shear force. Strength of the beam is design criterion for bending moment and shear force, While the stiffness of the beam is the design criterion for deflection of the beam.

In this unit, you shall be introduced to several types of beams, supports & loadings. After that, methods of drawing Shear Force Diagram (SFD) & Bending Moment Diagram (BMD) for cantilever, simply supported beam & overhanging beam for different kinds of loadings have been discussed.

Objectives

After studying this unit, you should be able to

• recognize the types of beam and kind of support when it appears in building, structural system, etc.,
• explain the shear force and bending moment and the relation among shear force, bending moment & rate of loading,
• draw the shear force & bending moment diagrams for any kind of beam subjected to any kind of loading system, and
• illustrated the location of maximum bending moment & location of zero bending moment (point of contraflexure).