Beam (structure)

A beam is a structural element designed to carry loads perpendicular to its long (or "horizontal") axis. This contrasts with a strut or column, which bears its load perpendicular to its short (or "vertical") axis. A beam's mode of deflection is primarily by bending, as loads produce reaction forces at the beam's support points and internal bending moments, shear, stresses, strains, and deflections. Beams are characterized by their manner of support, profile (shape of cross-section), equilibrium conditions, length, and material.

Any structural element, in any orientation, that primarily resists loads applied laterally across the element's axis is a beam. While beams are most commonly found in architecture and civil engineering, they are also found in automobile frames, aircraft components, machine frames, and many other mechanical or structural systems.