Connections (Part 1.1) - Eurocodes

1 Brussels, 18-20 February 2008 Dissemination of information workshop1 EUROCODESB ackground and ApplicationsConnections (Part ) Connections (Part )Eurocode 9: Design of aluminium University of Technology, Eindhoven, TNO Built Environment and Geosciences, Delft, The NetherlandsBrussels, 18-20 February 2008 Dissemination of information workshop2 EUROCODESB ackground and ApplicationsConnections (Part ) of Joints Welds Bolts, rivets Adhesives Hybrid remarksBrussels, 18-20 February 2008 Dissemination of information workshop3 EUROCODESB ackground and ApplicationsIntroductionImportance of Joining TechnologyDesign of aluminium structures requires knowledge of: Available joining techniques Design of connectionsTo arrive at optimum performance at low is a key technology in aluminium structural engineeringBrussels, 18-20 February 2008 Dissemination of information workshop4 EUROCODESB ackground and ApplicationsIntroductionTypes of joints Primary structures Welded Connections Bolted Connections Riveted Connections Adhesive joints Special joints Solid state welding Joints with cast parts Snap joints, rolled joints etc.

2 Joints in Thin-walled Structures Thread forming and self-drilling screws Blind rivets Cartridge fired pin Spot weldingBrussels, 18-20 February 2008 Dissemination of information workshop5 EUROCODESB ackground and ApplicationsIntroductionAdvantage of welded connection Saving work and material Absence of drilling Tight joints No crevice corrosion Joint preparation by extrusionBrussels, 18-20 February 2008 Dissemination of information workshop6 EUROCODESB ackground and ApplicationsIntroduction Requirements of joints Structural requirements Strength Stiffness Deformation capacity Non-structural requirements Economic aspects Durability Tightness AestheticsBrussels, 18-20 February 2008 Dissemination of information workshop7 EUROCODESB ackground and ApplicationsIntroduction Principles of designBrussels, 18-20 February 2008 Dissemination of information workshop8 EUROCODESB ackground and ApplicationsIntroduction Strength, stiffness and deformation capacity Strength: Analytical determination Determination by tests Stiffness: Influence on entire structure Influence on force distributionin Connections Distribution of loads Deformation capacity.

3 Prevention of brittle fracture Redistribution of stressesBrussels, 18-20 February 2008 Dissemination of information workshop9 EUROCODESB ackground and ApplicationsJoining technology Welding Gas welding Metal arc welding TIG MIG Electric resistance welding Spot welding Seam welding Solid state welding Ultrasonic welding Electron beam welding Friction weldingBrussels, 18-20 February 2008 Dissemination of information workshop10 EUROCODESB ackground and ApplicationsJoining technology Principle of TIG weldingBrussels, 18-20 February 2008 Dissemination of information workshop11 EUROCODESB ackground and ApplicationsJoining technology Principle of MIG weldingBrussels, 18-20 February 2008 Dissemination of information workshop12 EUROCODESB ackground and ApplicationsJoining technology Friction stir weldingBrussels, 18-20 February 2008 Dissemination of information workshop13 EUROCODESB ackground and ApplicationsJoining technology Screws, bolts and rivets Aluminium Steel Thread insertsBrussels, 18-20 February 2008 Dissemination of information workshop14 EUROCODESB ackground and ApplicationsJoining technology Thread insertsEnsatHeli-coilBrussels, 18-20 February 2008 Dissemination of information workshop15 EUROCODESB ackground and ApplicationsJoining technologySolid RivetsBrussels.

4 18-20 February 2008 Dissemination of information workshop16 EUROCODESB ackground and ApplicationsJoining technology Special jointsProfile to profile jointsGroove and tongueHooked connectionBrussels, 18-20 February 2008 Dissemination of information workshop17 EUROCODESB ackground and ApplicationsJoining technology Resistance spot weldingAdvantages Fast, automatic Small distortion Excellent weld strengthLimitations Only lap joints Max. mm thickness Access to both sides required Expensive equipmentBrussels, 18-20 February 2008 Dissemination of information workshop18 EUROCODESB ackground and ApplicationsJoining technologyThread forming and selfdrillingscrewsThread formingSelf drilling andSelf drilling andscrewthread formingthread formingBrussels, 18-20 February 2008 Dissemination of information workshop19 EUROCODESB ackground and ApplicationsJoining technologyAdhesive bondingAdvantages Microstructure unaffected Joining of different materials Joining of very thin parts High fatigue strength Good vibration dampingDisadvantages Low strength Pretreatment of surfaces Ageing Tolerance of process parametersBrussels.

5 18-20 February 2008 Dissemination of information workshop20 EUROCODESB ackground and ApplicationsJoining technology Structure of adhesive parent strength oxide oxide strength between oxide layer and strength between interface and strength of adhesiveBrussels, 18-20 February 2008 Dissemination of information workshop21 EUROCODESB ackground and ApplicationsJoining technologyFailure of adhesive jointsAdhesion failureCohesion failureMixed failureBrussels, 18-20 February 2008 Dissemination of information workshop22 EUROCODESB ackground and ApplicationsJoining technology Properties of adhesivesAdhesive baseTemperature Range COne-component epoxy110-130 Two-component epoxy60-90 Phenolic adhesive80-120 Methylacrylate80-100 Polyurethane80-100 Polyamide120-140 Silicone180-190 Brussels, 18-20 February 2008 Dissemination of information workshop23 EUROCODESB ackground and ApplicationsJoining technology Design of adhesive metal jointsBrussels.

6 18-20 February 2008 Dissemination of information workshop24 EUROCODESB ackground and ApplicationsDesign of jointsWelded Connections Design of welded joints Strength of the welds Strength of the HAZ Design guidance applicable for Welding process MIG or TIG (up to t= 6 mm) Approved welder and welding procedure Prescribed combinations of parent and filler metal Statically loaded structures Above conditions not fulfilled Primary structures testing Secondary structures or non loaded members Mw= 1,6 Brussels, 18-20 February 2008 Dissemination of information workshop25 EUROCODESB ackground and ApplicationsDesign of joints Heat-affected zone (HAZ) Heat-treatable alloysCondition T4 or higherHAZ softening(6xxx and 7xxx series) Non-heat treatable alloysTIG welding morein work-hardened than MIG(3xxx and 5xxx series)weldingBrussels, 18-20 February 2008 Dissemination of information workshop26 EUROCODESB ackground and ApplicationsDesign of joints HAZ softening factor HAZA lloy seriesCondition HAZ (MIG) HAZ (TIG)6xxxT41,01,0T50,650,60T60,650,507xx xT40,900,70T60,800,605xxxH220,860,86H240 ,800,803xxxH14, H16, H180,600,60 Brussels, 18-20 February 2008 Dissemination of information workshop27 EUROCODESB ackground and ApplicationsDesign of joints Extent of HAZ (bHAZ)bHAZ(mm)

7 MIGTIG0 < t 6 mm20306 < t 12 mm30-12 < t 25 mm35-t> 25 mm40-Brussels, 18-20 February 2008 Dissemination of information workshop28 EUROCODESB ackground and ApplicationsDesign of joints Characteristic strength weld metal (fw) Lower than parent metal strength Depending on filler metal used (appropriate 5xxx or 4xxx series)Characteristic strength values weld metal fw[N/mm2]Parent metalFillermetal3003 H125083 O5454 H246060 T56005 T66061 T66082 T67020 T65356-240220160160190210260404395--1501 50170190210 Brussels, 18-20 February 2008 Dissemination of information workshop29 EUROCODESB ackground and ApplicationsDesign of joints Design of butt welds Strength members full penetration butt welds Throat thickness equal to thickness t Effective length equals total weld length when run-on and run-off plates are usedBrussels, 18-20 February 2008 Dissemination of information workshop30 EUROCODESB ackground and ApplicationsDesign of joints Design stresses Normal stress, perpendicular to weld axis Shear stress Normal + shear stressMwwf Mwwf 6,0 Mwwf +223 Brussels.

8 18-20 February 2008 Dissemination of information workshop31 EUROCODESB ackground and ApplicationsDesign of joints Design of fillet welds Strength of fillet welds Throat section Forces acting on throat section Throat section Effective throat thickness a Effective length Longitudinal fillet weld Length > 100 a Non uniform stressesReduction ofweld lengthBrussels, 18-20 February 2008 Dissemination of information workshop32 EUROCODESB ackground and ApplicationsDesign of joints Effective throat thicknessWith positive root penetration:a= 1,2 aor a+ 2 mm or a= a+ apen(verified by testing)Brussels, 18-20 February 2008 Dissemination of information workshop33 EUROCODESB ackground and ApplicationsDesign of joints Forces acting on a fillet weldStresses , and , acting on the throat section of a fillet weldThroat sectionBrussels, 18-20 February 2008 Dissemination of information workshop34 EUROCODESB ackground and ApplicationsDesign of joints Design strength fillet weld Stresses comparison stress c: Design stresses.

9 ()2223 ++=CMwwCf Brussels, 18-20 February 2008 Dissemination of information workshop35 EUROCODESB ackground and ApplicationsDesign of joints Design strength HAZ Tensile force perpendicular to failure plane HAZ butt welds(Full penetration butt welds)(Partial penetration butt welds)te= effective throat thicknessfa,HAZ= Characteristic strength HAZMwHAZaf , ttfMweHAZa ,Brussels, 18-20 February 2008 Dissemination of information workshop36 EUROCODESB ackground and ApplicationsDesign of joints HAZ fillet welds(Toe of the weld , full cross-section)(At the fusion boundary)For shear forces and combined tensile / shear forces similar rules applyMwHAZaf , tgfMwHAZa1, g1 Brussels, 18-20 February 2008 Dissemination of information workshop37 EUROCODESB ackground and ApplicationsDesign of joints Design of Connections with combined weldsTwo designed for stresses in parent metal of the different parts of the joint Linear Elastic acting on joint are distributed to the welds that are mostsuited to carry them Plastic ApproachBrussels, 18-20 February 2008 Dissemination of information workshop38 EUROCODESB ackground and ApplicationsDesign of joints Bolted and riveted connectionsPositioning of holesDirection ofload transferEnd distance e1: min.

10 1,2 dEdge distance e2: max. 4 t+ 40 mm corrosion environment12 t+ 150 mm no corrosionSpacing p1: min. 2,2 dSpacing p2: min. 2,4 dmax. 14 tor 200 mmBrussels, 18-20 February 2008 Dissemination of information workshop39 EUROCODESB ackground and ApplicationsDesign of joints Categories of bolted connectionsShear Connections Category A: Bearing type Shear resistance Bearing resistance Category B: Slip-resistant at serviceability limit state Add. check at ult. limit state: shear and bearing Category C: Slip-resistant at ultimate limit state Add. check: shear and bearingTension connectio