1 / 15

BEAM-COLUMNS

BEAM-COLUMNS. PROF. V. KALYANARAMAN Department of Civil Engineering Indian Institute of Technology Madras Chennai 600036 email: kalyan@civil.iitm.ernet.in. DESIGN OF BEAM COLUMNS. INTRODUCTION SHORT & LONG BEAM-COLUMNS Modes of failure Ultimate strength

riona
Download Presentation

BEAM-COLUMNS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. BEAM-COLUMNS PROF. V. KALYANARAMAN Department of Civil Engineering Indian Institute of Technology Madras Chennai 600036 email: kalyan@civil.iitm.ernet.in

  2. DESIGN OF BEAM COLUMNS INTRODUCTION SHORT & LONG BEAM-COLUMNS Modes of failure Ultimate strength BIAXIALLY BENT BEAM-COLUMNS DESIGN STRENGTH EQUATIONS Local SectionFlexural Yielding Overall Member Flexural Buckling STEPS IN ANALYSING BEAM-COLUMNS ANALYSIS EXAMPLE SUMMARY

  3. INTRODUCTION Causes Of Bending In Beam Columns • Eccentric Compression • Joint Moments in Braced Frames Rigid • Sway Moments in Unbraced Frames • Biaxial Moments in Corner Columns of Frames z y x

  4. fy fy fy fy = + M fy fy fy fy fy Fc M Combined compression and bending, P & M Pcs Axial compression MP Bending moment SHORT BEAM-COLUMNS Pcs = Ag * fy MP = Z * fy P

  5. Short column loading curve Fc/Pcs F0/Pcs Fcl /Pcs Eqn. 3 M/Mp O Mmax/Mp 1.0 Mo/Mp M / MP  1.0 Fc / Pcs + 0.85 M / MP 1.0 Eqn 3 SHORT BEAM-COLUMNS 1.0 Failure envelope

  6. M0  M0 P * 0 Linear Non-Linear LONG BEAM COLUMNS Non – Sway Frame

  7. M 0 M0 LONG BEAM-COLUMNS Sway Frames

  8. M0/MP= 0.0 P/Pcr = 0.0 A 1.0 0.5 M0 0.1 P . Pcr 0.5 0.8 1.0 0.8  O  LONG BEAM-COLUMNS B

  9. Failure Envelope LONG BEAM-COLUMNS 1.0 Short column loading curve Fc/Pcs F0/Pcs Long columns loading curve Fcl /Pcs Eqn. 3 1.0 Mmax/Mp Mo/Mp M / MP

  10. After correcting for sway and bow (P- and P-) 1.0 Short column failure envelope Fc/Pcs After correction for (P-) effect Fcl/Pcs 1.0 Mx/Mpx Major axis bending SLENDER BEAM-COLUMNS Uniaxial Bending After correcting for sway and bow (P- and P-) 1.0 Short column failure envelope Fc/Pcs After correction for (P-) effect Fcl/Pcs A P*  P* 1.0 My/Mpy Minor axis bending

  11. SLENDER BEAM-COLUMNS Mx Mpx A P/Py < 0.25 C’ B E P/Py >0.5 C D Short Column F F’ Slender Column F’’ O  Fig. 7 Beam-column Moment Rotation Behaviour

  12. Fcl/Pcs /r = 0 /r increases Mx/Mpx My/ Mpy Fig. 8 beam-columns under Biaxial Bending BEAM-COLUMNS / BIAXIAL BENDING

  13. DESIGN STRENGTH EQUATIONS Local Section Failure Overall Member failure

  14. STEPS IN BEAM-COLUMN ANALYSIS Steps in Beam-Column Analysis • Calculate section properties • Evaluate the type of section • Check using interaction equation for section yielding • Check using interction equation for overall buckling

  15. SUMMARY • Short Beam-Columns Fail by Section Plastification • Slender Beam-Columns may Fail By • Section Plstification • Overall Flexural Yielding • Overall Torsional-Flexural Buckling • Intetaction Eqs. Conservatively Consider • P- and P- Effects • Advanced Analysis Methods Account for P-  and P-  Effects, directly & more accuraely

More Related