资源描述:
《cold-formed steel construction(don s.wolford)》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、SECTIONEIGHTCOLD-FORMEDSTEELCONSTRUCTIONDonS.WolfordConsultingEngineerMiddletown,OhioWei-WenYuUniversityofMissouriRollaRolla,MissouriThetermcold-formedsteelconstruction,asusedinthissection,referstostructuralcomponentsthataremadeofflat-rolledsteel.Thissectiondealswithfabricatedco
2、mponentsmadefrombasicformsofsteel,suchasbars,plates,sheet,andstrip.COLD-FORMEDSHAPESCold-formedshapesusuallyimplyrelativelysmall,thinsectionsmadebybendingsheetorstripsteelinroll-formingmachines,pressbrakes,orbendingbrakes.Be-causeoftherelativeeaseandsimplicityofthebendingoperat
3、ionandthecompar-ativelylowcostofformingrollsanddies,thecold-formingprocesslendsitselfwelltothemanufactureofuniqueshapesforspecialpurposesandmakesitpossibletousethinmaterialshapedformaximumstiffness.Theuseofcold-formedshapesforornamentalandothernon-load-carryingpur-posesiscommon
4、place.Doorandwindowframes,metal-partitionwork,non-load-bearingstuds,facing,andallkindsofornamentalsheet-metalworkemploysuchshapes.Thefollowingdealswithcold-formedshapesusedforstructuralpurposesintheframingofbuildings.Thereisnostandardseriesofcold-formedstructuralsections,suchas
5、thoseforhot-rolledshapes,yetalthoughgroupsofsuchsectionshavebeendesigned(‘‘Cold-formedSteelDesignManual,’’AmericanIronandSteelInstitute,110117thSt.,NW,Washington,DC20036).Forthemostpart,however,cold-formedstructuralshapesaredesignedtoserveaparticularpurpose.Thegeneralapproachof
6、thedesigneristhereforesimilartothatinvolvedinthedesignofbuilt-upstructuralsections.8.18.2SECTIONEIGHTCold-formedshapesinvariablycostmoreperpoundthanhot-rolledsections.Theywillbefoundtobemoreeconomicalunderthefollowingcircumstances:1.Wheretheirusepermitsasubstantialreductioninwe
7、ightcomparedtohot-rolledsections.Thisoccurswhererelativelylightloadsaretobesupportedovershortspans,orwherestiffnessratherthanstrengthisthecontrollingfactorinthedesign.2.Inspecialcaseswhereasuitablecombinationofstandardhot-rolledshapeswouldbeheavyanduneconomical.3.Wherequantitie
8、srequiredaretoosmalltojustifytheinvestmentnecessarytop