சி. எஸ். ஐ. ஆர். - கட்டமைப்பு பொறியியல் ஆராய்ச்சி நடுவம்

Studies on cold-formed steel building components

• Cold-formed steel sections are derived at room temperature through press braking and roll forms CFS sections are thin and light-weight
• Applicable to use for low rise residential buildings

• Experimental and numerical studies on lipped channel compression members
• Experimental and numerical studies on plain channel compression members
• Experimental studies flexural members
• Development of self-drilling screw connection

Studies on lipped channel axial compression members

Studies on lipped channel axial compression members

• Intermediate length columns   
  • Varying
  • Thickness
  • Flange width
  • Depth of the section                                            

Load-deflection behaviour

Experimental Set-up

Distortional buckling FE & Exp

• Buckling Modes
  • Local buckling (L)
  • Distortional buckling (D)
  • Flexural buckling (F)
  • Torsional buckling (T)
• Failure Modes:
  
  • L+T
  • L+F+D
  • L+D+F-T

  Studies on plain channel under eccentric compression loading

• Under Eccentric loading
• Varying
  
  • Depth of the section
  • Eccentricity of loading
  • Towards and away from shear centre
• Buckling Modes
  
  • Local buckling (L)
  • Flexural buckling (F)
• Supports : Fixed-fixed
• Displacement controlled loading
• Failure Mode: Combined
  • Local buckling of web
  • Local buckling of flange

Experimental Set-up

local  buckling

local  buckling

local  buckling

Distortional buckling of flexural members

• Lipped channel sections
• Symmetrical loading at shear-centre is ensured by combined section

• Simple supports
• The beam assembly is restrained,  except at constant moment region

• Buckling Modes
  • Local buckling (L)
  • Distortional buckling (F)
  • Failure: distortional buckling followed by local buckling of the compression flange

Experimental Set-up

Distortional buckling

FEA results

Self-drilling screw joints

• In India, self-drilling screws are used to connect secondary elements    (Roofing sheets, side cladding, purlins)

• Literature: Self-drilling screws can  transfer shear efficientlyAttempt has been made to utilize these screws to connect  cold-formed steel beam and column
• Lap joints have been tested under tensile loading
• Screw head is in contact with thick sheets
• Failure modes
  • Bearing
  • Tilting
  • Bearing-tilting