The extent of space between two supports of a structure. Also, the structure so supported.

The distance between the inner faces of the supports of a span

The center-to-center distance between the supports of a span

An external moment tending to cause part of a structure to rotate or bend, equal to the algebraic sum of the moments about the neutral axis of the section under consideration

An internal moment equal and opposite to a bending moment, generated by a force couple to maintain equilibrium of the section being considered

The perpendicular distance a spanning member deviates from a true course under transverse loading, increasing with load and span, and decreasing with an increase in the moment of inertia of the section or the modulus of elasticity of the material

A slight convex curvature intentionally built into a beam, girder, or truss to compensate for an anticipated deflection

A shear force at a cross section of a beam or other member subject to bending, equal to the algebraic sum of transverse forces on one side of the section

The shearing stress developed to prevent slippage along horizontal planes of a beam under transverse loading, equal at any point to the vertical shearing stress at that point. Also called longitudinal shearing stress.

An imaginary line passing through the centroid of the cross section of a beam or other member subject to bending, along which no bending stresses occur

A combination of compressive and tensile stresses developed at a cross section of a structural member to resist a transverse force, having a maximum value at the surface furthest from the neutral axis

The shearing stress developed along a cross section of a beam to resist transverse shear, having a maximum value at the neutral axis and decreasing nonlinearly toward the outer faces

A formula defining the relationship between bending moment, bending stress, and the cross-sectional properties of a beam

The sum of the products of each element of an area and the square of its distance from a coplanar axis of rotation

A geometric property that indicates how the cross-sectional area of a structural member is distributed and does not reflect the intrinsic physical properties of a material

A geometric property of a cross section, defined as the moment of inertia of the section divided by the distance from the neutral axis to the most remote surface

The buckling of a structural member induced by compressive stresses acting on a slender portion insufficiently rigid in the lateral direction

The point in the cross-sectional plane of a structural member through which a transverse load must pass in order to prevent torsion or twisting of the member about a longitudinal axis

Lines depicting the direction but not the magnitude of the principal stresses in a beam

The tensile and compressive stresses resulting from the interaction of bending and shear stresses at a cross section of a beam

A graphic representation of the variation in magnitude of the external shears present in a structure for a given set of transverse loads and support conditions

A graphic representation of the variation in magnitude of the bending moments present in a structure for a given set of transverse loads and support conditions

A net resultant of shear forces that acts vertically upward on the left part of the structure being considered

A net resultant of shear forces that acts vertically downward on the left part of the structure being considered

A bending moment that produces a concave curvature at a section of a structure

A bending moment that produces a convex curvature at a section of a structure

A beam or other rigid structural member extending beyond a fulcrum and supported by a balancing member or a downward force behind the fulcrum

A point at which a structure changes curvature from convex to concave or vice versa as it deflects under a transverse load; theoretically, an internal hinge and therefore a point of zero moment

The part of a beam that is thickened or deepened to develop greater moment resistance

A simple beam supported by the cantilevers of two adjoining spans with pinned construction joints at points of zero moment. Also called hung-span.

The distance between inflection points in the span of a fixed-end or continuous beam, equivalent in nature to the actual length of a simply supported beam

A beam resting on simple supports at both ends, which are free to rotate and have no moment resistance

A projecting beam supported at only one fixed end

A simple beam extending beyond one its supports

A simple beam extending beyond both of its supports

A beam having both ends restrained against translation and rotation. The fixed ends transfer bending stresses, increase the rigidity of the beam, and reduce its maximum deflection.

A beam extending over more than two supports in order to develop greater rigidity and smaller moments than a series of simple beams having similar spans and loading