What is a Beam Structure in Construction?

Beam structure is a horizontal structural element used in construction to sustain and resist the laterally applied loads coming on it. It forms the traditional description of any building or civil engineering structural elements.

The beam structure can be made either by means of concrete, steel or wood or composite materials. A beam is characterized based on its support, profile, length, and material. There are different types of beams in terms of supports provided, the material used, based on load conditions, etc.

Load Action on Beams

The beam structure, under the action of laterally applied loads, is subjected to bending. The beam has reaction forces at the end supports and moments as a result of load action.

The total effect on the beam due to the load is expressed in the form of shear force and bending moments. The internal effect in the beam is in the form of internal stresses, strains, and deflections of the beam.

Bending Action on a Cantilever Beam AB - Load Application (W). Bending Moment is calculated about a section X-X.

Classification of Beams

The main classification of the beam is performed based on the supports. They are:

1. Simply Supported Beam
2. Fixed Beam
3. Over Hanging Beam
4. Continuous Beam
5. Cantilever Beam
6. Double Overhanging Beam
7. Trussed Beam

Shear Force and Bending Moment of Beams

The beam is a flexural member. Where the structural element is subjected to lateral loading which brings the beam to show flexural character. The primary load, the beam is designed to resist is the bending moment. But in addition to this traverse and vertical shear force are also considered.

Also Read: What is a Flexural Member?

What is Shear force?

Shear force is defined as the algebraic sum of all reaction forces (traverse forces) that is acting to the left or to the right of the section selected.

What is Bending Moment?

Bending Moment can be defined as the algebraic sum of moments which is calculated about a section drawn in the beam. The moment at any section is calculated as the product of force and the centroidal distance between the section and the location of the force.

Also Read: How to Calculate the Bending Moment of a Beam?