BeamGeneral InputSIFPSLength, L26.88m88.20ftMember DimensionFy50ksiHw, h2900mm114.17in9.51ftE70 ElectrodesTw, tw25mm0.98in0.08ftAllowable shear stress21ksiWf, wf2000mm78.74in6.56ftUnbraced Length Mejor88.20ftTf, tf12mm0.47in0.04ftUnbraced Length Minor88.20ftSince the compression flange carries a uniform load, assume that it is restrained against rotation.Maximum Moment5640k-ftMaximum Shear250KipASelection of the Web Platea)Recommended height of WebL/127.35ftOR88.20inProvided height of Web9.51ftOR114.17inFinal height of Web, hw /h7.35ftOR88.20inb)h/tw h/tw242.79inSo tw0.36inc)For closely spaced stiffnerh/tw282.84inSo tw0.31inFinal thickness of Web0.50ind)hw88.20intw0.50inAweb44.10in2h/tw176.40Allowable bending stress Fb0.6 Fy30ksicheck if reduction of the allowable bending stress137.18hw/tw176.40So Allowable bending stress must be reducedFb = 0.6 Fy30ksiReduced allowable bending stress, Fb'27.93ksiBSelection of Flange PlatesAf = bf*tf20.13in2The minimum flange thickness in order to prevent flange local buckling isKc0.38& h/tw> 70 i.e176.40tf1.11but use1.20inSo bf = Af/tf18.20but use20.00inCDesign for bending stress, Moment of InertiaFinal Section DimentionWeb h88.20in7.35ftWeb t0.50in0.04ftFlange w20.00in1.67ftFlange t1.20in0.10ftI, Moment of Inertia151594.8in4S, Section Modulus3399.0in3rT5.1inh/tw176.40M16578k-ftM25640k-ftM1/M21.17Cb3.38But max value is 2.3So Cb2.3Lu88.20ftlu/rT209.5068.50153.17fb19.91ksiFb'27.93ksiOkDIntermediate stiffenersA584/SQRT Fy77.50380/SQRT Fy53.74h/tw176.40So Fv2.67Developed Shear Stress250So Intermediate Stiffeners are requiredBFind the location of the first stiffener from each end.B.1At LeftRa250kipAw88.20in2fv2.83ksiSubstitute for Fv = fvCv0.16