AISC LRFD 1.pdf

110 DESIGN SHEAR STRENGTH [App. G3.æ 1-C övVn = 0.6FywAwç Cv+÷è 1.15 1 + ( a/ h)2ø(A-G3-2)Also see Appendix G4 and G5.Tension field action is not permitted for end-panels in non-hybrid plate girders, allpanels in hybrid and web-tapered plate girders, and when a/hexceeds 3.0 or [260 /h / t w ]. For these cases, the nominal strength is:V= 0.6F A Cn yw w v(A-G3-3)The web plate buckling coefficient k v is given ask v5= 5 + ( a / h )2(A-G3-4)except that k v shall be taken as 5.0 if a/hexceeds 3.0 or [260 / h / t w ] 2 .The shear coefficient C v is determined as follows:kEv h kEv(a) For 1.10 £ £ 1.37 :F t Fyw w yw1.10 kEv/ FCv=h/twyw(A-G3-5)(b) ForhtwkEFv> 1.37 :yw1.51kEvCv=2( h/ t ) Fwyw(A-G3-6)G4. TRANSVERSE STIFFENERSTransverse stiffeners are not required in plate girders where h / t w £ 245 . E/F yw ,or where the required shear V u , as determined by structural analysis for the factoredloads, is less than or equal to 0.6f v F yw A w C v , where C v is determined for k v 5 and v 0.90. Stiffeners may be required in certain portions of a plate girder to developthe required shear or to satisfy the limitations given in Appendix G1. Transversestiffeners shall satisfy the requirements of Appendix F2.3.When designing for tension field action, the stiffener area A st shall not be less thanLRFD Specification for Structural Steel Buildings, December 27, 1999AMERICAN INSTITUTE OF STEEL CONSTRUCTION