developments in connections in cold-formed building structures and design specifications

Developments in connections incold-formed building structures anddesign specificationsA W Toma

TNO Building and Construction Research, The Netherlands

SummaryFor all building structures national andinternational Codes are important in the designprocess. This is also true for connections incold-formed building structures. Lightweightconstruction has developed rapidly in this field,but the Codes, by their very nature are far slowerin their development. For this reason a number ofconnection types are not fully covered, or notcovered at all, by the existing Codes. Designersthus face a different situation with respect toconnections than for usual steel buildings. Thispaper describes the relation between traditionalconnection systems and existing Codes. The idealsituation should be that the development of

connection systems and their treatment in Codes(fastener and structural codes) should be wellbalanced for appropriate application in thebuilding industry. But, because of thecomparatively slow development of the Codes,new developments (clinching, air driven pins andadhesive bonding) require guidance on how toproceed in design.

For selection of a connection system theimportant structural and non-structuralparameters are surveyed. With the use of theseparameters it should be possible to choosesystem, a fit for purpose i.e. a reliable (safe anddurable) and economical system.

Key words: connections in cold-formed steel structures; connections in thin-walled structures; mechanical fastening;resistance welding; fillet welding; adhesive bonding; standards; clinching

Prog. Struct. Engng Mater. 2003; 5:145–152 (DOI: 10.1002/pse.152)

Introduction

The application of thin-walled steel, formed by a coldrolling into sections or sheeting (e.g. trapezoidal,sinusoidal), is a still growing market in the buildingindustry[1,2]. Mostly the application is with acontinuously hot-dip zinc-coated or aluminium/zinc-coated finish layer, with or without an organiccoating. The application of thin-walled steel may bechosen for the combined properties of light weightand structural capacities. As a consequence of its easyformability it is often in use as a finishing accessory(formed mostly by a press braking process). For thebuilding industry well-known value-addedapplications (Fig. 1) are: composite action with timber

board for floors and walls, perforated sheeting forbetter acoustic performance, composite action ofsheets (as skin) and insulating core material insandwich panels, perforated sections for easyassemblage in storage racks, steel–concrete compositeslabs, etc.

Besides these well-known applications, which havea strong market share, new applications are focusedon steel framing for the housing industry. It is notnecessary that the application is ‘all steel’, a goodopportunity is provided by building elements basedon steel framing (such as floors, facades, partitionwalls, roofs).

For a good and economical application ofthin-walled steel elements it is a first priority to

Steel Construction

AbbreviationsAISI¼American Iron and Steel InstituteCEN¼Comite Europeen de Normal-isation (European Committee for Stan-dardisation)

CSA¼Canadian Standards AssociationECCS¼ European Convention for Con-structional Steelwork

ECSC¼ European Community for Steeland Coal

SAA¼ Standards Association of Austra-lia

Copyright & 2003 John Wiley & Sons, Ltd. Prog. Struct. Engng Mater. 2003; 5:145–152

have available connection techniques which arefit for the purpose and economical in use[3]. ‘Fitfor purpose’ implies regard to the structural capacitiesand sustainable capabilities. ‘Economical inuse’ implies regard to the price/quality ratio of theconnection system and easy (and reliable)assemblage.

Many connection systems have been developedespecially for thin-walled steel. Up to now only a fewof these have been treated in the structural Codes andRecommendations[4–12]. To make broad use of theavailable connection techniques in the buildingindustry it is preferable that the development of thesystems and the treatment in Codes (includingstructural ones) are well balanced, otherwise thestructural capacities should be determined on thebasis of research results.

This review summarizes the development inconnection systems for cold-formed steel structures,the forthcoming systems for the building industry andthe history and status of Codes andRecommendations. As said already the newapplications of thin-walled steel are focused on steelframing and the new connection systems are alsorelated to those applications.

Survey of connection possibilities

For this review the following distinctions are made:

* fastener}the connecting element in a fastening;

* fastening}interaction of one mechanical fastener(or a discrete spot weld) with the surroundingmaterial;

* connection}group (one or more) of fastenings orcontinuous (fillet welds or adhesive bonds)systems.

For making connections in cold-formed structuresa number of techniques are available, some are thesame as for the thicker hot-rolled steel and others arespecific for thinner steel, and make use of:

* mechanical fasteners;* welding;* deformation of the sheet material;* adhesive bonding.

CONNECTIONS WITH MECHANICAL FASTENERS

The traditionally used mechanical fasteners are blindrivets[3,5,13,14], nuts and bolts[5,14–18], screws (self-tapping or self-drilling-self-tapping)[5,13,19–25] andpowder actuated fasteners (cartridge fired pins)[5,13,20].Well known applications are:

* blind rivets}seam connections in sheeting(Fig. 2a), bracing connection in storage racks;

* nuts and bolts}for the thicker elements such asoverlap in purlins[26] (Fig. 2b);

* screws}connection of sheets to the main structureor seam connection, also the main connection ofsandwich panels[9] (Fig. 1c);

* powder-actuated fasteners}connection of sheets tothe main structure (Fig. 2c)[27];

(a) (b)

(c) (e)(d)

Fig. 1 Value-added applications of cold-formed steel in the building industry: (a) timber board plus section in floor; (b) perforatedsheeting; (c) connection of sandwich panel; (d) perforated sections in storage racks; (e) steel–concrete composite slab (Courtesy ofComite International du Profilage a Froid, Staalbouwkundig Genootschap, ECCS).

STEEL CONSTRUCTION146


* air-driven pins}also connection of sheets to themain structure[28].

The new applications are:

* connection of plywood to cold formed sections forsteel frame building in housing}the fasteners usedare screws or air-driven nails (Fig. 1a),

* connection of stainless steel in structuralapplications[29]}the fasteners used are screws,blind rivets, nuts and bolts, for each application theright material (stainless steel quality and grade) hasto be chosen.

In zinc-coated thin-walled steel or stainless steel,the use of friction-grip bolted connections is notpossible. As a consequence of creep of the zinc(relatively thick compared with the steel) or thestainless steel, the preload disappears.

CONNECTING BY WELDING

The welding methods applied are resistance welding(line or spot) and fusion welding[30,31]. Both methodscan be used for fasten thin to thin steel or thin to thicksteel. For welding it is important to take into accountthe possible coatings on the sheet material. These willinfluence the quality of the weld to a large extent.

Welding of thin-walled steel in the buildingindustry is applied in the steel frame elements forhousing (Fig. 3) and in storage racks (end plates tosections).

CONNECTING BY DEFORMING SHEET MATERIAL

In roofing some systems make use of a standing seamwhich is deformed and folded on site for thelongitudinal connection between the sheets.

A new application in the building industry isclinching[32–34]. This technology is extensively used inthe automotive industry and is now transferred to theapplication in steel frame elements for housing.A clinch is a one-point fastening machined by a punchand a die (Fig. 4). Both sides of the connection must beaccessible. A new clinching system speciallydeveloped for the building industry is the so-calledrosette (from Rosette Systems Ltd., Finland). This isformed by first penetrating (drilling or punching) twoplates and then deforming the edges of the hole intoeach other with a special tool. This system can beused, e.g. for connecting the elements in roof trussesto produce high-strength and reliable connections.The advantage over standard clinches is the higherstrength capacity and the reliability for automation.

(a) (b)

(c)

Fig. 2 Some applications of mechanical fasteners in connections:(a) blind rivet in seam connection in sheeting; (b) nuts and boltswith overlap of purlins; (c) powder-actuated connection ofsheeting to the main structure (Courtesy of Comite Internationaldu Profilage a Froid, ECCS).

stud

track

Fig. 3 Application of fusion welds in steel frames for housing(Courtesy of CSSBI).

S-type

H-type

O-type

Fig. 4 Some examples of clinches (Courtesy University ofEdinburgh).

CONNECTIONS IN COLD-FORMED STRUCTURES 147


CONNECTING BY ADHESIVE BONDING

A well-known structural application of adhesivebonding in the building industry is the connection ofthin sheets (skins) to insulation material (core) for theproduction of sandwich panels.

Other possible structural applications of adhesivebonding need for the research to derive the designprocedures for each application. These designprocedures should include the aspects of ageing,deformation capacity (redistribution of stresses) andprevention of peeling[35].

History and status of Recommendationsand Codes

In 1983 the ECCS published the EuropeanRecommendations for mechanical fasteners andconnections in thin-walled (cold-formed) sheetingand sections[4,5]. Most of the research for theserecommendations was partly financed by the ECSC.The recommendations were based largely on adeterministic philosophy, although load and materialfactors have been used. The basis for thedetermination of these factors was to achieveconsistency in design practice with the allowablestress format used previously.

Then in 1996 CEN published the Eurocode (as aEuropean pre-standard) for cold-formed thin-gaugemembers and sheeting[7]. The chapter concerningconnections was largely based on the ECCS EuropeanRecommendations, but with a probabilistic analysis ofthe material factors[36,37] within the framework of thelimit states philosophy. This led to a single materialfactor for all of the failure modes: gM¼ 1.25 and tomechanical models for the failure modes (designformulae) based on the tensile strength instead of theyield strength of the steel. The connecting systemstreated in the ENV are mechanical fasteners (bolts,screws, blind rivets and cartridge-fired pins) andwelding (resistance spot welding and fillet welding).In September 2002 the ENV 1993-1-3 was convertedinto the prEN 1993-1-3[12]. After a formal vote in 2003this draft will lead to the EN 1993-1-3. Compared withthe ENV only some adjustments of the formulae forfillet welding have been done.

In North America two important standards havelong been available. These are the one given by AISIin the USA[10] (first edition in 1946) and the one fromthe CSA in Canada[6] (first edition in 1963). In the nearfuture Canada, Mexico and the United States ofAmerica will have one joint common standard. Thatcommon standard has both formats, ASD (allowablestress design) and LRFD (load resistance factordesign).

Another important standard with regard toconnections is the joint Code by the Australian andNew Zealand Standards Associations[8]. For thisregion special attention is necessary for loading effects

by cyclones[38,39], i.e. high values of wind loads andspecific repeated load spectra. This standard is of theLRFD type. All the Codes mentioned provideformulae to determine the strength of a connection.

Because the field of application of these formulaecover a wide range, they are always on theconservative side. Therefore in a number of situations(mass production of elements, situations withconnections in which forces are higher than thestrength according to the formulae) it can beprofitable to determine the strength and stiffness bymeans of testing[4,5]. All the Codes mentioned providethe possibility to determine the strength and stiffnessof connections by means of testing.

Requirements and selection procedurefor connections

Because connections contribute to a substantial extentto the costs of thin walled steel structures (as forhot-rolled steel structures[40]) the selection procedurefor the type of connection should have a high priority.Table 1 provides the parameters for such a selectionprocedure. The procedure starts with the non-structural requirements to determine the type offastening (for corrosion with regard to fasteningsheeting see Wieland[41]).

Then, the structural requirements are used todetermine the number of fasteners (or weld length, or

.........................................................................

.........................................................................

.........................................................................

.........................................................................

Table 1 Requirements for connections in thin-walled structures

Structural requirements

1. Strength (under static load and/or repeated load)2. Stiffness (for load distribution in the structure and connec-

tions)3. Deformation capacity (for reasons of load redistribution)

Non-structural requirements

1. Economic aspectsa) Total number of connections which have to be madeb) Assembly in the factory or on sitec) Skills requiredd) Tools requirede) Ability to dismantlef) Design lifetimeg) Installed costs of the connections

* Cost of the fasteners* Direct labour cost* Indirect labour cost* Cost of tools, with possible mechanization* Cost of required energy supply* Cost of maintenance of tools* Development costs.

2. Durability with respect toa) Chemical aggressiveness of the environmentb) Possible galvanic corrosionc) Stress corrosion (e.g. chlorides and elevated tempera-

tures for some types of stainless steel)3. Watertightness for roofs and cladding4. Aesthetics



adhesive width) or spacings[42]. In detailing theconnections, it is important that designers are fullyaware of the structural properties of the thin-walledelements in terms of stiffness, strength anddeformation capacity. The most effective mechanismof force transfer is by shear in the connection, becausethen the stiffness and deformation of the connectionleads to acceptable behaviour. Another aspect is thatcold-formed sections are ‘open sections’. i.e. the cross-section can deform, leading to second-order forces inthe connections. In general the designer shouldprevent these second-order forces.

For adhesive bonding it is important to use aquality assurance procedure to achieve a connection

which is fit for the purpose. Table 2 shows a genericoverview of such a quality assurance scheme foradhesive bonding starting with the design stage up tothe use of the structure[43].

Forces in connections

The forces in connections depend on the externalloading on the structure and on the properties of thestructure (stiffness, e.g. in the diaphragm action oftrapezoidal sheeting, and deformation capacitybecause ductile behaviour allows the use of designmodels of the connections with ‘simplified’ forcedistributions)[44]. The external loads are determined

......................................................................................................................................................

......................................................................................................................................................

Table 2 Generic model for quality assurance of adhesive bonded connections

Activity Quality requirement Method of validation/control

Corrective action

1. Selection and sourcing ofmaterials (adherends)

a) Joint designb) Specified component

a) Test recordsb) Supplier certificationsc) Published datad) Experience of previous use

a) Return to supplierb) Reselectc) Design change

2. Selection and sourcing ofadhesives

a) Joint designb) Production requirements

a) Test recordsb) Supplier certificationsc) Published datad) Experience of previous use

a) Return to supplierb) Reselectc) Design change

3. Storage of adhesives Requirements specified byadhesive suppliera) Shelf-lifeb) Packagingc) Temperatured) Humidity

a) Inspection of packagesb) Batch/data numberc) Control of storage facility

a) Rejectb) Retest and recheck life

4. Pretreatment of surfaces Requirements specified bymaterial propertiesa) Cleaningb) Surface removalc) Chemical treatment

a) Use tested procedure(error proof)

b) Trained staff

Re-treat

5. Assembly a) Component fit-up:correct component location

b) Application: type, mix,quantity, temperature,humidity

a) Inspectionb) Use of jigsc) Metering by calibrated dispenserd) Use tested procedure

(error proof)e) Trained staff

a) Re-jigb) Select correct

componentsc) Rejectd) Reapply

6. Cure Requirements specified byadhesive suppliera) Timeb) Temperaturec) Pressured) Heating/cooling rate

a) Use tested procedure(error proof)

b) Trained staffc) Time/temperature records

a) Rejectb) Re-cure

7. Final inspection Joint meets designrequirementsa) Strengthb) Environmentc) Appearanced) Reliabilitye) Durability

a) Test programmeb) Review of process

documentation and records

a) Rejectb) Concessionc) Design change

8. Pre-usage storage Joint meets designrequirementsa) Strengthb) Environmentc) Appearanced) Reliabilitye) Durability

Correct storage review oftest reports and supplierinformation

a) Rejectb) Design change



by national standards. These loads will cause shear,tension or a combination of these forces in theconnections. The forces in connections can bedistinguished as:

* primary forces}forces which are directly causedby the load;

* secondary forces}forces which are indirectlycaused by the load and which may be neglected inthe presence of sufficient deformation capacity.

Typical loads and actions for building structures aredead weight, imposed loads, wind, snow,temperature differences. Under certain conditions it isnecessary to take into account the repetitive characterof the loads, such as wind load on sheeting whichcauses tension in the fasteners (the thin sheet aroundthe fastener can fail by fracturing through low-cyclefatigue caused by the repetitive bending). In theexisting design rules this aspect is covered.

Design strength of connections

The design strength of connections depends on thetype of fasteners and type and thickness of sheets tobe connected. Every combination of fastener type andsheet possesses a related failure mode. Therefore, aunique strength level is associated with every failuremode. These strengths can be determined either bymeans of Code formulae or by testing[4,5,11]. From theperspective of limit states design, testing leads todetermination of characteristic strengths. Suitablematerial factors allow the design strength to beobtained from the characteristic strength. In theCodes formulae are given to compute the designstrengths associated with each failuremode[6–10,12,29]. The different failure modes to beconsidered for connections with mechanicalfasteners are:

1. Connections loaded in shear (Fig. 5):* shear of the fastener (Fig. 5a);

* crushing of the fastener (Fig. 5b);* tilting and pull-out of the fastener (Fig. 5c);* yield in tearing (thinner sheet only Fig. 5d,

both sheets Fig. 5e);* end failure (Fig. 5f);* failure of the net cross-section (Fig. 5g).

2. Connections loaded in tension (Fig. 6):* tension failure of the fastener (Fig. 6a);* pull-out of the fastener (Fig. 6b);* pull-over (head punched through the sheet

by shearing Fig. 6c);* pull through (head punched through the

sheet by bending Fig. 6d);* gross distortion of the sheeting (Fig. 6e).

For connections loaded by a combination of tensionand shear the Codes provide interaction formulae.

The main parameters for controlling the designvalues of connections are sheet thickness, sheet tensilestrength, fastener material (type of adhesive bond),fastener diameter (width and length of bond layer,length of weld), and end and pitch distances. Anotherimportant item for connections is the necessarydeformation capacity, because this can lead to simplemodels to determine the force distribution over theconnection. In the testing recommendations, thisminimum deformation capacity is defined to ensurecertain distribution of forces over the connection andthe structure. Codes providing formulae for thedetermination of the design strengths cover therequirement of adequate deformation capacitythrough rules which state that failure modes,characterized by insufficient deformation capacity(e.g. failure by shear of the fastener itself), should beassociated with a higher level of strength than that ofthe failure modes, characterized by sufficientdeformation capacity (e.g. hole-bearing).

As to the design of connections making use ofadhesive bonding, the following aspects areimportant:

* determination of the external loads andenvironmental conditions (the latter parameter is

(a) (b)

(d) (e)

(f) (g)

(c)

Fig. 5 Failure modes of connections loaded in shear: (a) shear of the fastener; (b) crushing of the fastener; (c) tilting and pull-out of thefastener; (d) yield of the thinner sheet only; (e) yield of both sheets; ( f ) end failure; (g) failure of the net cross-section (Courtesy of ECCS).



needed to appraise ageing properties), as well asthe temperatures and humidity during use (inorder to define possible fluctuation);

* choice of the adhesive system, with reference totype of adhesive, surface condition of the parts tobe connected and preparation of those surfaces;

* detailing of the overlap of the parts to be connected(prevention of peeling stresses is necessary).

Conclusions

Connections in cold-formed building structures aremade with traditional systems and with newlydeveloped ones. The traditional systems aremechanical fasteners (screws, blind rivets, nuts andbolts, cartridge-fired pins) and welding (fillet welds,resistance spot welds). These systems are treated inthe codes with regard to design strengths. Standardsfor the mechanical properties of fasteners are stilllacking for a number of fasteners. The designer thusdepends in many cases on information from themanufacturer of the fastener.

New systems are under development for thebuilding industry, among them clinching, air-drivenpins and adhesive bonding. As to clinching, researchis currently in progress aimed at developing designprocedures. As to air-driven pins, it can be expectedthat, when there is a high demand from the Europeanmarket, design specifications will soon follow. As toadhesive bonding, reliability assessment of the designprocedure, even for its sole application in sandwichpanels, is still necessary.

The main issues under investigation are the designprocedure for clinched connections and, in floor

systems, for the connection of cold-formed sectionswith timber board made by adhesive bonding. Infuture investigations should be focused on moreapplications of connections with adhesive bondingand new connection techniques which allow moreprefabrication, together with optimal assemblagetechniques on site.

References

[1] Hancock GJ. Light gauge construction. Progress in Structural Engineering

and Materials 1997: 1(1): 25–30.

[2] Davies JM. Light gauge construction: developments in applications.

Progress in Structural Engineering and Materials 2000: 2(1): 26–33.

[3] Stark JWB & Toma AW. Connections in thin-walled structures. In:

Rhodes J & Walker AC (eds) Developments in Thin-Walled Structures–1. Essex: Applied

Science Publishers. 1982: 159–203.

[4] ECCS TC 7. The design and testing of connections in steel sheeting and

sections. European Recommendations for Steel Construction. Brussels: ECCS publication

21. 1983.

[5] ECCS TC 7. Mechanical fasteners for use in steel sheeting and sections.

European Recommendations for Steel Construction. Brussels: ECCS publication 42. 1983.

[6] S136-94. Cold Formed Steel Structural Members. Canadian Standards

Association, Rexdale (Toronto), Ontario, Canada, 1994.

[7] ENV 1993-1-3 (European pre-standard). Eurocode 3: Design of steel

structures. Part 1.3: General rules, Supplementary rules for cold formed thin gauge

members and sheeting Chap 8. CEN, Brussels, February 1996.

[8] Cold-formed steel structure code AS/NZ 4600: 1996. Standards

Australia/Standards New Zealand, Sydney, 1996.

[9] ECCS TC 7 & CIB W56. European Recommendations for Sandwich Panels,

Part 1: Design. Rotterdam/Brussels: CIB Report publication 257/ECCS publication

115. 2001. Chap. 7, 117–131.

[10] AISI. Specification for the Design of Cold-Formed Steel Structural Members.

Washington DC. 2001.

[11] prEN 1990: 2002 (Provisional European standard). Eurocode 0: Basis

of Structural Design. Annex D (Informative): Design Assisted by Testing. CEN, Brussels,

July 2001.

[12] prEN 1993-1-3: 2002 (Provisional European standard). Eurocode 3:

Design of Steel Structures. Part 1.3: General Rules, Supplementary Rules for Cold-Formed

(a) (b)

(c) (d)

(e)

Fig. 6 Failure modes of connections loaded in tension: (a) tension failure of the fastener; (b) pull-out of the fastener; (c) pull-over; (d)pull-through; (e) gross distortion of the sheeting (Courtesy of ECCS).



Thin Gauge Members and Sheeting. Chap. 8. Design of joints. CEN, Brussels,

September 2002.

[13] Lixin Fan. Contribution to steel sheet connections of screws, blind rivets

and cartridge fired pins. Doctoral Thesis. University of Liege. 1996.

[14] Nicolaas T & Toma AW. Design tools, new applications of cold-formed

steel in buildings; new connection methods. (ECSC research project: 7210-PG-059).

TNO report 2000-CON-R4028, Delft, December 2000.

[15] Boston RM & Pask JW. Structural Fasteners and Their Application. London:

BCSA; 1978.

[16] Zadanfarrokh F & Bryan ER. Testing and design of bolted connections

in cold-formed steel sections. Proceedings of the 11th International Specialty Conference

on Cold-Formed Steel Design and Construction, University of Missouri-Rolla, October

1992: 625–662.

[17] LaBoube RA, Yu WW & Carril JL. Serviceability limit state for cold-

formed steel bolted connections. Proceedings of the 3rd International Workshop on

Connections in Steel Structures III (Behaviour, Strength and Design), Trento, Italy, May

1995: 403–411.

[18] Maiola CH, Malite M, Goncalves RM & Neto JM. On the structural

behaviour of bolted connections in thin sheets and cold-formed steel members.

Proceedings of the 3rd European Conference on Steel Structures, Coimbra, Portugal,

September 2002: 957–966.

[19] Großberndt H & Kniese A. Untersuchung uber Querkraft-Zugbean-

spruchungen sowie Folgerungen uber kombinierte Beanspruchungen von

Schraubenverbindungen bei Stahlprofilblech Konstruktionen. Der Stahlbau 1975: 44:

(10, 11).

[20] Klee S & Seeger T. Vorschlag zur vereinfachten Ermittlung von zulassigen

Kraften fur Befestigungen von Stahltrapezblechen. Veroffentlichung des Instituts fur

Statik und Stahlbau der Technischen Hochschule Darmstadt. 1979.

[21] Pekoz T. Design of cold-formed steel screw connections. Proceedings of

the 10th International Specialty Conference on Cold-Formed Steel Design and Construction,

University of Missouri-Rolla, October 1990: 575–588.

[22] Fan LX, Rondal J & Cescotto S. Numerical simulation of lap screw

connections. Thin-walled Structures 1997: 29(1–4): 235–241.

[23] Rogers CA & Hancock GJ. Bearing design of thin sheet steel screwed

connections. Proceedings of the 14th International Specialty Conference on Cold-Formed

Steel Design and Construction, University of Missouri-Rolla, October 1998: 481–494.

[24] Hettmann R & Saal H. Tragverhalten von Verbindungen des Leichtbaus.

11. DASt-Forschungskolloquium Karlsruhe, 30 September–1 October 1999.

[25] LaBoube RA & Sokol MA. Behavior of screw connections in residential

construction. Journal of Structural Engineering 2002: 128(1): 115–118.

[26] Toma T & Wittemann K. Design of cold-formed purlins, rails

restrained by sheeting. Journal of Constructional Steel Research 1994: 31(2–3): 149–168.

[27] Beck H & Engelhardt MD. Net section efficiency of steel coupons with

power actuated fasteners. Journal of Structural Engineering 2002: 128(1): 12–21.

[28] Baur SW & Suaris W. Evaluation of cold-formed steel connections

attached with pneumatically driven pins. Proceedings of the 15th International Specialty

Conference on Cold-Formed Steel Design and Construction, University of Missouri-Rolla,

October 2000: 619–633.

[29] ENV 1993-1-4 (European pre-standard). Eurocode 3: Design of steel

structures. Part 1.4: General rules, Supplementary rules for stainless steels. CEN,

Brussels, 1996.

[30] Stark JWB & Soetens F. Welded connections in cold-formed sections.

Proceedings of the 5th International Specialty Conference on Cold-Formed Steel Structures,

University of Missouri-Rolla, November 1980: 591–636.

[31] Garc!ııa JDC & Pena AA. Welded connections of cold-formed steel

structures with Cu–Si. Proceedings of the 3rd European Conference on Steel Structures,

Coimbra, Portugal, September 2002: 1049–1057.

[32] Pedreschi RF, Sinha BP & Davies RJ. End fixity in cold-formed steel

sections using press joining. Thin-walled Structures 1997: 29(1–4): 257–271.

[33] Pedreschi RF, Sinha BP & Lennon R. The shear strength of mechanical

clinching in cold-formed steel structures. Working paper, Department of Architecture,

University of Edinburgh, September 1998.

[34] Sedlacek G, Schneider R, Hieta J & Ryan I. New connection

methods}clinched connections. (ECSC research project: 7210-PR-059). Report

from RWTH Aachen, April 2001.

[35] van Straalen IJJ. Development of design rules for structural adhesive

bonded joints: a systematic approach. Doctoral Thesis. Delft University of Technology.

2000.

[36] Bryan ER, Sedlacek G, Toma AW & Weynand K. Evaluation of test

results on connections in thin-walled sheetings and members in order to obtain

strength functions and suitable model factors. Background Report to Eurocode

3}Annex A, August 1990.

[37] Toma A, Sedlacek G & Weynand K. Connections in cold-formed

steel. Thin-walled Structures 1993: 16(1–4): 219–237.

[38] Mahendran M & Mahaarachchi D. Cyclic pull-outstrength of steel roof

and wall cladding systems. Proceedings of the 15th International Specialty Conference on

Cold-Formed Steel Design and Construction, University of Missouri-Rolla, October 2000:

647–658.

[39] Mahaarachchi D & Mahendran M. Improved numerical modelling of

crest-fixed steel cladding systems subject to pull-through failures. Proceedings of

the 3rd European Conference on Steel Structures, Coimbra, Portugal, September 2002:

645–655.

[40] Steenhuis CM, Stark JWB & Gresnigt AM. Cost-effective connec-

tions. Progress in Structural Engineering and Materials 1997: 1(1): 18–24.

[41] Wieland H. Korrosionsprobleme in der Profilblech- und Flachdach-

Befestigungstechnik. Befestigungstechnik Bau of SFS Stadler Befestigungs- und Umform-

technik AG. Heerbrugg, Switzerland. 1988: 1–41.

[42] LaBoube RA, Yu WW & Jones ML. Spacing of connections in

compression flanges of built-up cold-formed beams. Proceedings of the 14th

International Specialty Conference on Cold-Formed Steel Design and Construction,

University of Missouri-Rolla, October 1998: 563–578.

[43] EUREKA Project EU716. Quality Assurance in Adhesive Technology.

Abington Publications, 1998. ISBN 1-855-73259-9.

[44] Walter W. Flexible nodes in calculations of thin-walled structures.

Proceedings of the 3rd European Conference on Steel Structures, Coimbra, Portugal,

September 2002: 1189–1198.

A W Toma, MSc

TNO Building and Construction Research,

P.O. Box 49, 2600 AA Delft, The Netherlands

E-mail: [email protected]



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