A beam is a structural element that primarily resists loads applied laterally to the beam’s axis. Its mode of deflection is primarily by bending. The loads applied to the beam result in reaction forces at the beam’s support points. The total effect of all the forces acting on the beam is to produce shear forces and bending moments within the beam, that in turn induce internal stresses, strains and deflections of the beam. Beams are characterized by their manner of support, profile (shape of cross-section), equilibrium conditions, length, and their material.
Beams are traditionally descriptions of building or civil engineering structural elements, but any structures such as automotive automobile frames, aircraft components, machine frames, and other mechanical or structural systems contain beam structures that are designed to carry lateral loads are analyzed in a similar fashion.
Beams are the most common type of structural form, and in this unit we deal mostly with developing mathematical models to predict the strength and stiffness of beams. Beams divert a load, thus creating an open space beneath them,
As we have seen, this causes curving of the beam – in this case the top of the beam gets shorter and the bottom gets longer.