is800-9bc

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Dr S R Satish Kumar, IIT Madras 1 Section 9 Members subjected to Combined Forces (Beam-Columns)

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  • Dr S R Satish Kumar, IIT Madras*Section 9 Members subjected to

    Combined Forces

    (Beam-Columns)

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*SECTION 9 MEMBER SUBJECTED TO COMBINED FORCES

    9.1General9.2Combined Shear and Bending9.3 Combined Axial Force and Bending Moment 9.3.1 Section Strength 9.3.2 Overall Member Strength

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*9.2Combined Shear and Bending

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*9.2Combined Shear and BendingSections subjected to HIGH shear force > 0.6 Vd a) Plastic or Compact Section

    b) Semi-compact Section

    Mfd = plastic design strength of the area of c/s excluding the shear area and considering partial safety factorV = factored applied shear force; Vd = design shear strength

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*9.3 Combined Axial Force and Bending Moment DESIGN OF BEAM COLUMNSINTRODUCTION

    SHORT & LONG BEAM-COLUMNS Modes of failure Ultimate strengthBIAXIALLY BENT BEAM-COLUMNS

    DESIGN STRENGTH EQUATIONS Local Section Flexural YieldingOverall MemberFlexural Buckling

    STEPS IN ANALYSING BEAM-COLUMNS

    SUMMARY

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*INTRODUCTIONOccurrence of Beam ColumnsEccentric CompressionJoint Moments in Braced Frames Rigid Sway Moments in Unbraced FramesBiaxial Moments in Corner Columns of Frames

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*SHORT BEAM-COLUMNSPPy = Ag*fy Mp = Zp*fy

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*SHORT BEAM-COLUMNS M = P e

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*LONG BEAM COLUMNS Non Sway FrameMmax = Mo + P

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*LONG BEAM-COLUMNS Sway FramesM = Mo + P

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*LONG BEAM-COLUMNS BCm accounts for moment gradient effects

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*LONG BEAM-COLUMNS Mo/MpMmax/MpM / MP1.01.0

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*SLENDER BEAM-COLUMNSModified Strength Curves for Linear Analysis Minor axis bendingUniaxial Bending

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*BEAM-COLUMNS / BIAXIAL BENDING

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*9.3 Combined Axial Force and Bending Moment

    9.3.1 Section Strength 9.3.1.1 Plastic and Compact Sections

    9.3.1.3 Semi-compact section fx. fy /m0

    9.3.2 Overall Member Strength

    9.3.2.1 Bending and Axial Tension Md

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*9.3.2.2 Bending and Axial CompressionCmy, Cmz = equivalent uniform moment factor as per table 18Also CmLT

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*STEPS IN BEAM-COLUMN ANALYSISSteps in Beam-Column AnalysisCalculate section propertiesEvaluate the type of sectionCheck using interaction equation for section yieldingCheck using interction equation for overall bucklingBeam-Column Design using equivalent axial load

    Dr S R Satish Kumar, IIT Madras

  • Dr S R Satish Kumar, IIT Madras*SUMMARYShort Beam-Columns Fail by Section Plastification

    Slender Beam-Columns may Fail BySection PlstificationOverall Flexural YieldingOverall Torsional-Flexural Buckling

    Intetaction Eqs. Conservatively ConsiderP- and P- Effects

    Advanced Analysis Methods Account for P- and P- Effects, directly & more accuraely

    Dr S R Satish Kumar, IIT Madras