AISC LRFD 1.pdf

xxviGLOSSARYFlexible connection. A connection permitting a portion, but not all, of the simple beamrotation of a member endFloor system. The system of structural components separating the stories of a buildingForce. Resultant of distribution of stress over a prescribed area. A reaction that developsin a member as a result of load (formerly called total stress or stress). Generic term signifyingaxial loads, bending moment, torques, and shearsFracture toughness. Measure of the ability to absorb energy without fracture. Generallydetermined by impact loading of specimens containing a notch having a prescribedgeometryFrame buckling. A condition under which bifurcation may occur in a frameFrame instability. A condition under which a frame deforms with increasing lateraldeflection under a system of increasing applied monotonic loads until a maximumvalue of the load called the stability limit is reached, after which the frame will continueto deflect without further increase in loadFully composite beam. A composite beam with sufficient shear connectors to develop thefull flexural strength of the composite sectionHigh-cycle fatigue. Failure resulting from more than 20,000 applications of cyclic stressHSS. Hollow structural sections that are prismatic square, rectangular or round productsof a pipe or tubing mill and meet the geometric tolerance, tensile strength and chemicalcomposition requirements of a standard specificationHybrid beam. A fabricated steel beam composed of flanges with a greater yield strengththan that of the web. Whenever the maximum flange stress is less than or equal to theweb yield stress the girder is considered homogeneousHysteresis loop. A plot of force versus displacement of a structure or member subjected toreversed, repeated load into the inelastic range, in which the path followed duringrelease and removal of load is different from the path for the addition of load over thesame range of displacementInclusions. Nonmetallic material entrapped in otherwise sound metalIncomplete fusion. Lack of union by melting of filler and base metal over entire prescribedareaInelastic action. Material deformation that does not disappear on removal of the force thatproduced itInstability. A condition reached in the loading of an element or structure in which continueddeformation results in a decrease of load-resisting capacityJoint. Area where two or more ends, surfaces, or edges are attached. Categorized by typeof fastener or weld used and method of force transferK bracing. A system of struts used in a braced frame in which the pattern of the strutsresembles the letter K, either normal or on its sideLamellar tearing. Separation in highly restrained base metal caused by through-thicknessstrains induced by shrinkage of adjacent filler metalLRFD Specification for Structural Steel Buildings, December 27, 1999AMERICAN INSTITUTE OF STEEL CONSTRUCTION