Forces applied perpendicularly to the longitudinal axis of a member. Transverse loading causes the member to bend and deflect from its original position, with internal tensile and compressive strains accompanying change in curvature.
Concentrated loads are applied over areas or lengths which are relatively small compared with the dimensions of the supporting member. Examples are a heavy machine occupying limited floor area, wheel loads on a rail, or a tie rod attached locally. Loads may be stationary or they may be moving, as with the carriage of a crane hoist or with truck wheels.
Distributed loads are forces applied continuously over large areas with uniform or nonuniform intensity. Closely stacked contents on warehouse floors, snow, or wind pressures are considered to be uniform loads. Variably distributed load intensities include foundation soil pressures and hydrostatic pressures.
Members subjected to bending by transverse loads are classed as beams. The span is the unsupported length. Beams may have single or multiple spans and are classified according to type of support, which may permit freedom of rotation or furnish restraint (see illustration).