ABSTRACT
Steelmembersunderbendingare¥exuralmembers(beams)whichareusedtotransfertransverseloadstothesupports.Thetransverseloadsactingonabeammayinducetheactions ofbending,shearandbearinginthebeam.Therefore,steelbeamsneedtobedesignedfor bending,shearandbearing.Steelbeamsareoftenmadeofthin-walledelementsbyhotrolling,weldingandcoldforming.TypicalsectionsforsteelbeamsaregiveninFigure4.1.The behaviourofasteelbeamdependsonitssectionslenderness,materialpropertiesandmemberslenderness.LateralandtorsionalrestraintsalongthesteelbeamsigniŠcantlyincrease itsmembermomentcapacity.Asaresult,theuseoflateralandtorsionalrestraintsleadsto signiŠcanteconomies.Steelplategirdersareoftenmadeofslenderwebswhichmayundergo shearandbearingbuckling.Transversewebandload-bearingstiffenersareattachedtothe websofsteelplategirderstoincreasetheirbucklingcapacities.Thedesignofasteelbeam forstrengthincludestheveriŠcationofitssectionandmembermomentcapacities,web shear and bearing capacities and the design of web stiffeners and restraints.
