Beam Flashcards
A rigid structural member designed to carry and transfer transverse loads across space to supporting elements
Beam
The extent of space between two supports of a structure. Also, the structure so supported
Span
The distance between the inner faces of the supports of a span
Clear Span
The center-to-center distance between the supports of a span
Effective 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
Bending Moment
An internal moment equal and opposite to a bending moment, generated by a force couple to maintain equilibrium of the section being considered
Resisting Moment
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.
Deflection
A slight convex curvature intentionally built into a beam, girder, or truss to compensate for an anticipated deflection
Camber
A shear force at a cross section of a beam or other members subject to bending, equal to the algebraic sum of transverse forces on one side of the section
Transverse Shear
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
Neutral axis
A combustion of compressive and tension 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
Bending stress
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
Vertical shearing stress
The shearing stress developed to prevent slippage along longitudinal planes of a beam under transverse loading equal at any point to the vertical shearing stress at that point. Also called longitudinal shearing stress
Horizontal shearing stress
A formula defining the relationship between bending moment, bending stress and the cross-sectional properties of a beam. Bending stress is directly proportional to bending moment and inversely proportional to the moment of inertia of a beam section
Flexure formula
The sum of the products of each element of area and the square of its distance from a coplanar axis of rotation. Moment of Inertia is 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.
Moment of Inertia
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
Section modulus
The buckling of a structural member induced by compressive stresses acting on a slender portion insufficiently rigid in the lateral direction
Lateral buckling
The tensile and compressive stresses resulting from the interaction of bending and shear stresses at a cross section of a beam
Principal stresses
Lines depicting the direction but not the magnitude of the principal stresses in a beam
Stress Trajectories
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
Shear center
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
Shear diagram
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. The overall deflected shape of a structure subject to bending can often be inferred from the shape of its moment diagram
Moment diagram
A beam resting on simple support at both ends, which are free to rotate and have no moment resistance. As with any statically determinate structure, the values of all reactions, shears, and moments for a simple beam are independent of its cross-sectional shape and material
Simple beam
A projecting beam supported at only one fixed end
Cantilever Beam
A beam or other rigid structural member extending beyond a fulcrum and supported by a balancing member or a downward force behind the fulcrum
Cantilever
A simple beam extending beyond one its supports. The overhang reduces the positive moment at mid span whole developing a negative moment at the base of the cantilever over the support
Overhanging Beam
A simple beam extending beyond both of its supports
Double Overhanging Beam
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
Fixed-End Beam
A simple beam supported by the cantilevers of two adjoining spans with pinned construction joints at points of zero moment
Suspended-Span, Hung-Span
A net resultant of shear forces that acts vertically upward on the left part of the structure being considered
Positive shear
A net resultant of shear forces that acts vertically downward on the left part of the left part of the structure being considered
Negative shear
A bending moment that produces a concave curvature at a section of a structure
Positive moment
A bending moment that produces a convex curvature at a section of a structure
Negative moment
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
Inflection point
The part of a beam that is thickened or deepened to develop greater moment resistance. The efficiency of a beam can be increased by shaping its length in response to the moment and shear values which typically vary along its longitudinal axis
Haunch
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
Effective length
