7.5 : Beams

Beams are integral components of structural engineering and construction, designed to support loads applied at various points along their length. These long, straight members can be classified based on geometry, cross-section, support type, and equilibrium condition.

Based on geometry, beams can be straight, tapered, or curved. Straight beams are the most common type and have a constant cross-section throughout their length. Tapered beams, on the other hand, have a varying cross-section along their length, while curved beams have a curved shape.

Beams can also have various cross-section shapes, such as I-beams, T-beams, L-beams, C-beams, or rectangular beams. Each shape is specifically designed to provide unique load-bearing capabilities, depending on the application and the loads that the beam must support.

Support types play a crucial role in the design and performance of beams. Beams can be classified as simply supported, overhanging, continuous, cantilever, or fixed, based on their supports. The distance between the supports is known as the span of the beam.

A simply supported beam has supports on both ends, while an overhanging beam extends beyond one of its supports. The cantilever beam is fixed at one end, extending from the fixed point. A continuous beam has support at more than two points along its length, and a fixed beam can either be fixed at both ends or supported at one end and fixed at the other end.

The reactions at the beam supports can be statically determinate if the supports involve only three unknowns. However, if there are additional unknowns, the beam becomes statically indeterminate.