Tóm tắt chương 2 kết cấu thép: Các loại mối nối và quy trình hàn | Môn Kết cấu bê tông & bê tông cốt thép - Đại học Sư phạm Kỹ thuật Thành phố Hồ Chí Minh

lOMoAR cPSD| 58759230 Steel Structures
Chapter 2 Steel connections Steel connections 1 .Introduction
2 .Welded connections 3. Bolted connections 4. Riveted connections 2 lOMoAR cPSD| 58759230 Introduction 3 lOMoAR cPSD| 58759230 Welded connections Introduction 4 1. Introduction
• Structural members are jointed by means of weld
• Why using welded connections?
o A more efficient use of materials o High speed of
fabrication and erection o Better for fatigue loads, impact loads, and vibrations 5 lOMoAR cPSD| 58759230 Welded connections 2. Types of welds o Butt welds o Fillet welds 6 lOMoAR cPSD| 58759230 Welded connections 2. Types of welds Types of butt welds Types of fillet welds 7 Welded connections 2. Types of welded joints 8 lOMoAR cPSD| 58759230 Welded connections 2. Types of welded joints For butt welds 9 Welded connections 2. Types of welded joints For butt welds 10 lOMoAR cPSD| 58759230 Welded connections 3. Weld defects 11 Welded connections 4 . Welding processes Arc welding
( manual welding ) Types of electrode 12 lOMoAR cPSD| 58759230 Welded connections 4. Welding processes
Automatic and semi-automatic welding 13 Welded connections 4. Welding processes axetylen oxy 3200 o C Gas welding 14 lOMoAR cPSD| 58759230 Welded connections 5 . Design strengths of welds Butt welds
o Compressive strength f wc = f o Tensile strength f wt = f (or 0.85f) o Shear strength f wv = f v ( 0 ,58f )
Strengths of materials corresponding to Steel different thickness t Ultimate Steel grade strength f u grade f f f 15 Welded connections 5. Design strengths of welds Fillet welds
o Shear strength (fracture plane 1) fwf (TCVN3223-1994)
o Shear strength (fracture plane 2) fws = 0.45fu
❖ fu - the standard ultimate strength of steel in tension lOMoAR cPSD| 58759230 Welded connections 16 5. Design strengths of welds Fillet welds
o Shear strength (fracture plane 1) fwf (TCVN3223-1994)
o Shear strength (fracture plane 2) fws = 0.45fu Types of electrode Normal tensile Design strength, strength, f wun f wf 17 Welded connections 6. Design of butt welds
Strength requirements o Welds subjected to normal
stress w c.fwt wc( ) o Welds subjected to shear
stress w c.fwv o Welds subjected to normal and shear stresses lOMoAR cPSD| 58759230 Welded connections
wtd 2 3 2 1,15 c.fwt
The effective area of the weld Aw=t x lw, where t and lw are the
effective thickness and length of the weld lw = l - 2t 18 7. Design of fillet welds Strength requirements
o For section 1: ( f .hf lw)
wf c.fwf o For
section 2: ( s.hf lw)
ws c.fws
wf - shear stress on section 1
ws- shear stress on section 2 l w l
10 mm - effective length of the weld 19 Welded connections lOMoAR cPSD| 58759230 Welded connections 7. Design of fillet welds 20 7 . Design of fillet welds h h h f min f f max 1 ,2 tmi n 21 lOMoAR cPSD| 58759230 Welded connections Welded connections 7. Design of fillet welds • lw 4hf and lw 40mm • lw 85 fhf : for side fil et welds • a 5 tmin 22 8. Worked examples Butt welds 23 lOMoAR cPSD| 58759230 Welded connections Welded connections 8. Worked examples Butt welds 24 lOMoAR cPSD| 58759230 25 Ch.3 Steel Connections LTK 26 lOMoAR cPSD| 58759230 Welded connections 8. Worked examples
Lap connection with side welds 1 N . ; kNN 2 (1 ). kN 27 Ch.3 Steel Connections LTK 28 lOMoAR cPSD| 58759230 Ch.3 Steel Connections LTK 29 Welded connections 8. Worked examples Lap connection For straps str N c fstr Astr For welds wf N c.fwf Awf lOMoAR cPSD| 58759230 Welded connections ws N c.fws Aws 30 8 . Worked examples Composite connection For butt welds N w c f ( wcwt ) A s A tr
For fillet welds connecting the straps and the steel plates N N wf str .f c wf ws str .cf ws str N w A str wf A ws A 31 Welded connections 8. Worked examples
Connection under shear and moment lOMoAR cPSD| 58759230 For section 1 M 2 V 2 wf Wwf Awf c fwf For section 2 ws M 2 V 2 c wsf Wws Aws 32 Ch.3 Steel Connections LTK 33 lOMoAR cPSD| 58759230 Welded connections Ch.3 Steel Connections LTK 34