VISUAL DICTIONARY II Flashcards
A curved structure for spanning an opening, designed to support a vertical load primarily by axial compression
ARCH
An arch constructed of individual stone or brick voussoirs.
MASONRY ARCH
Any of the wedge-shaped units in a masonry arch or vault, having side cuts converging at one of the arch centers.
VOUSSOIR
the first voussoir resting on the impost of an arch
SPRINGER
the wedge-shaped, often embellished voussoir at the crown of an arch, serving to lock the voussoir in place
KEYSTONE
The height of an arch from the spring line to the highest point of the intrados
RISE
The exterior curve, surface, or boundary of the visible face of an arch. Also called back.
EXTRADOS
A decorative molding or band on the face of an arch following the curve of the intrados
ARCHIVOLT
the inner curve or surface of an arch forming the concave underside
INTRADOS
the point at which an arch, vault, or dome rises from its support. Also, springing
SPRING
the highest part or point of a convex construction, such as an arch, vault, or roadway
CROWN
Either side of an arch curving down from the crown to the impost
HAUNCH
the uppermost part of an abutment, often in the form of a block, capital, or molding, from which an arch springs
IMPOST
the triangular-shaped sometimes ornamented area between the extrados of two adjoining arches, or between the left or right extrados of an arch and the rectangular framework surrounding it.
SPANDREL
Also, spandril
An archway having sides or jambs not at right angles with the face of its abutments.
SKEW ARCH
Any of several concentric rings of masonry forming an arch, esp. when each projects beyond the one below
ORDER
A crosspiece connecting the ribs in a centering
LAG
BOLSTER
A temporary framework for supporting a masonry arch or vault during construction until the work can support itself.
CENTERING
A board used as centering for a flat arch, slightly crowned to allow for setting of the arch.
CAMBER PIECE
Or
CAMBER SLIP
An arch shaped to develop only axial compression under a given loading. It is subject to bending if the loading pattern changes.
FUNICULAR ARCH
the funicular shape for an arch carrying a vertical load uniformly distributed along the length of the arch axis
INVERTED CATENARY
the funicular shape for an arch carrying a vertical load uniformly distributed over its horizontal projection
PARABOLA
An arched structure of timber, steel, or reinforced concrete, constructed as a rigid body capable of carrying bending stresses
RIGID ARCH
the manner in which an arch transforms the vertical forces of a supported load into inclined components and transmits them to abutments on either side of the archway
ARCH ACTION
The median line of an arched structure
ARCH AXIS
The set of resultants of thrusts and weight each part of an are imposes on the next lower one and must coincide with the arch axis for bending to be eliminated throughout an arch
LINE OF THRUST
the outward force or pressure exerted by one part of an arched structure against another
THRUST
the thrust of an arched structure on its abutments, proportional to the total load and span, and inversely proportional to the rise
DRIFT
A fixed frame structure having an arched form
FIXED ARCH
A two-hinged frame structure having an arched form
TWO-HINGED ARCH
A three-hinged frame structure having an arched form
THREE-HINGED ARCH
The part of a structure receiving and supporting the thrust of an arch, vault, or strut
ABUTMENT
An iron or steel rod serving as a structural tie especially one keeping the lower ends of an arch or frame from spreading
TIE ROD
An arch having a horizontal intrados with voussoirs radiating from a center below often built with a slight camber to allow for settling
FLAT ARCH
A flat arch having voussoirs inclined to the same angle on each side of the center
FRENCH ARCH
An arch having a continuously curved intrados especially a semicircular one
ROUND ARCH
An arch having a semicircular intrados
ROMAN ARCH
An arch struck from one or more centers below the springing line
SEGMENTAL ARCH
A stone or course of masonry having a sloping face against which the end of a segmental arch rests
SKEWBACK
A primitive form of arch consisting of two stones laid diagonally to support each other over an opening
TRIANGULAR ARCH
A false arch constructed by corbelling courses from each side of an opening until they meet at the midpoint where a capstone is laid to complete the work. The step reveals maybe smoothed but no arch action is effected.
CORBEL ARCH
An arch having one impost higher than the other
RAMPANT ARCH
An arch resting on imposts treated as downward continuations of the archivolt
STILTED ARCH
A round arch resting on two large corbels with curved faces
BELL ARCH
An arch having an intrados that widens above the springing before narrowing to a rounded crown
HORSESHOE ARCH
MOORISH ARCH
An arch having a cusped intrados with three round or pointed foils
TREFOIL ARCH
A three-centered arch having a crown with a radius much greater than that of the outer pair of curves
BASKET-HANDLE ARCH
ANSE DE PANIER
An arch having a pointed crown
POINTED ARCH
A pointed arch having two centers and radii equal to the span
EQUILATERAL ARCH
GOTHIC ARCH
A pointed arch having two centers and radii greater than the span
LANCET ARCH
A pointed arch having two centers and radii less than the span
DROP ARCH
A four-centered arch having an inner pair of curves with a radius much greater than that of the outer pair
TUDOR ARCH
An arch having a rise of less than half the span
SURBASED ARCH
A pointed arch, each haunch of which is a double curve with the concave side uppermost
OGEE ARCH
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
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 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
BENDING STRESS
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
TRANSVERSE SHEAR
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 horizontal planes of a beam under transverse loading, equal at any point to the vertical shearing stress at that point.
HORIZONTAL SHEARING STRESS
Or
LONGITUDINAL 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
It 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
the buckling of a structural member induced by compressive stresses acting on a slender portion insufficiently rigid in the lateral direction
LATERAL BUCKLING
At which part of the beam where only bending stresses exist?
at the extreme surfaces of a beam
At which part of the beam where only shear stresses exist?
at the neutral axis
the tensile and compressive stresses resulting from the interaction of bending and shear stresses at a cross section of a beam
PRINCIPAL STRESSES
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 beam resting on simple supports 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 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 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 of its supports. The overhang reduces the positive moment at midspan while 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 net resultant of shear forces that acts vertically upward on the left part of the structure being considered
POSITIVE SHEAR
A net resultant shear forces that acts vertically downward on 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 point at which a structure changes curvature from convex to concave or vice versa as it deflects under transverse load; theoretically, an internal hinge and therefore a point of zero moment
INFLECTION POINT
A bending moment that produces a convex curvature at a section of a structure
NEGATIVE MOMENT
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
A beam having both ends restrained against translation and rotation.
FIXED-END BEAM
A beam extending over more than two supports in order to develop greater rigidity and smaller moments than a series of multiple beams having similar spans and loading.
CONTINUOUS BEAM
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
A simple beam supported by the cantilevers of two adjoining spans with pinned construction joints at points zero moment
SUSPENDED SPAN
or
HUNG-SPAN