ARCHITECTURAL STRUCTURES: FORM, BEHAVIOR, AND DESIGN DR. ANNE NICHOLS SPRING 2015 lecture twenty one steel construction: nrmc.org bolted & welded connections Steel Bolts & Welding 1
Connections needed to: support beams by columns connect truss members splice beams or columns transfer load subjected to tension or compression shear bending Steel Bolts & Welding 2
Bolts bolted steel connections http://courses.civil.ualberta.ca Steel Bolts & Welding 3 (AISC - Steel Structures of the Everyday)
Welds welded steel connections http://courses.civil.ualberta.ca Steel Bolts & Welding 4
Bolts types materials high strength A307, A325, A490 location of threads included - N excluded - X friction or bearing (SC) always tightened Steel Bolts & Welding 5
Bolted Connection Design considerations bearing stress yielding shear stress single & double member rupture Steel Bolts & Welding 6
Bolts rarely fail in bearing holes considered 1/8 larger shear & tension single shear or tension double shear R R = F n n a n n R A b n R = F 2A b Ω R u φ v φ v R = 0.75 n Steel Bolts & Welding 7
Bolts Steel Bolts & Welding 8 http://www.fastenal.com
Bolts bearing deformation is concern deformation isn t concern long slotted holes R a n = 0.75 φ R =1. 2L tf 2. 4dtF n L c clear length to edge or next hole (ex. 1¼, 3 ) c c u u R φr u n R =1. 5L tf 3. 0dtF R =1. 0L tf 2. 0dtF n R n Ω c u u u u Steel Bolts & Welding 9
Bolts Steel Bolts & Welding 10 Lecture 121
Welded Connection Design considerations shear stress yielding rupture Steel Bolts & Welding 11
Welded Connection Design weld terms butt weld fillet weld plug weld throat field welding shop welding (AISC - Steel Structures of the Everyday) Steel Bolts & Welding 12
Welded Connection Design weld process melting of material melted filler - electrode shielding gas / flux potential defects weld materials E60XX E70XX F EXX = 70 ksi Steel Bolts & Welding 13
Welded Connection Design shear failure assumed throat T = 0.707 x weld size area A = T x length of weld weld metal generally stronger than base metal (ex. F y = 50 ksi) Steel Bolts & Welding 14
Welded Connection Design 16 minimum table maximum material thickness ( to ¼ ) 1/16 less min. length 7 5 3 16 8 4 x size min. 1 ½ Steel Bolts & Welding 15
Welded Connection Design shear R a R n Ω R φ R u n φ = 0.75 R = 0. 6F Tl = n EXX Sl area table for φs Steel Bolts & Welding 16
Framed Beam Connections angles bolted welded Steel Bolts & Welding 17
Framed Beam Connections terms coping (AISC - Steel Structures of the Everyday) Steel Bolts & Welding 18
Framed Beam Connections tables for standard bolt sizes & spacings # bolts bolt diameter, angle leg thickness bearing on beam web Steel Bolts & Welding 19
Framed Beam Connections welded example (shear) (AISC - Steel Structures of the Everyday) Steel Bolts & Welding 20
Framed Beam Connections welded moment example (AISC - Steel Structures of the Everyday) Steel Bolts & Welding 21
Framed Beam Connections welded/bolted moment example (AISC - Steel Structures of the Everyday) Steel Bolts & Welding 22
Framed Beam Connections welded/bolted moment example (AISC - Steel Structures of the Everyday) Steel Bolts & Welding 23
Beam Connections LRFD provisions shear yielding shear rupture block shear rupture tension yielding tension rupture local web buckling lateral torsional buckling Steel Bolts & Welding 24
Beam Connections φ = 0.75 Rn = 0.6 Fu Anv + U bs Fu Ant 0.6 Fy Agv + U bs Fu Ant where Ubs is 1 for uniform tensile stress block shear rupture Steel Bolts & Welding 25 tension rupture
Other Connections seated beam continuous beam to column beam to beam Steel Bolts & Welding 26
Other Connections splices The Royal Ontario Museum Toronto. Canada Daniel Libeskind (AISC - Steel Structures of the Everyday) Steel Bolts & Welding 27 http://courses.civil.ualberta.ca
Other Connections rigid frame knees gussets & joints (AISC - Steel Structures of the Everyday) Steel Bolts & Welding 28
Other Connections base plates anchor bolts bearing on steel bending of plate http://courses.civil.ualberta.ca Steel Bolts & Welding 29