AISC LRFD 1.pdf

xxivGLOSSARYColumn curve. A curve expressing the relationship between axial column strength andslenderness ratioCombined mechanism. A mechanism determined by plastic analysis procedure whichcombines elementary beam, panel, and joint mechanismsCompact section. Compact sections are capable of developing a fully plastic stress distributionand possess rotation capacity of approximately three before the onset of localbucklingComposite beam. A steel beam structurally connected to a concrete slab so that the beamand slab respond to loads as a unitConcrete-encased beam. A beam totally encased in concrete cast integrally with the slabConnection. Combination of joints used to transmit forces between two or more members.Categorized by the type and amount of force transferred (moment, shear, endreaction). See also SplicesCritical load. The load at which bifurcation occurs as determined by a theoretical stabilityanalysisCurvature. Rotation per unit length due to bendingDesign documents. Documents prepared by the designer (design drawings, designdetails, and job specifications)Design strength. Resistance (force, moment, stress, as appropriate) provided by elementor connection; the product of the nominal strength and the resistance factorDiagonal bracing. Inclined structural members carrying primarily axial load enabling astructural frame to act as a truss to resist horizontal loadsDiaphragm. Floor slab, metal wall, or roof panel possessing a large in-plane shear stiffnessand strength adequate to transmit horizontal forces to resisting systemsDiaphragm action. The in-plane action of a floor system (also roofs and walls) such thatall columns framing into the floor from above and below are maintained in the sameposition relative to each otherDouble concentrated forces. Two equal and opposite forces which form a couple on thesame side of the loaded memberDouble curvature. A bending condition in which end moments on a member cause themember to assume an S shapeDrift. Lateral deflection of a buildingDrift index. The ratio of lateral deflection to the height of the buildingDuctility factor. The ratio of the total deformation at maximum load to the elastic-limitdeformationEffective length. The equivalent length KL used in compression formulas and determinedby a bifurcation analysisEffective length factor K. The ratio between the effective length and the unbraced lengthof the member measured between the centers of gravity of the bracing membersLRFD Specification for Structural Steel Buildings, December 27, 1999AMERICAN INSTITUTE OF STEEL CONSTRUCTION