1、4Steel Design GuideExtended End-PlateMoment ConnectionsSeismic and Wind ApplicationsSecond Editioncover DG4 revise.qxd 4/28/2004 9:37 AM Page 14Steel Design GuideExtended End-PlateMoment ConnectionsThomas M. Murray, Ph.D., P.E.Montague-Betts Professor of Structural Steel DesignVirginia Polytechnic I
2、nstitute and State UniversityBlacksburg, VirginiaEmmett A. Sumner, Ph.D., P.E.Assistant ProfessorNorth Carolina State UniversityRaleigh, North CarolinaAMERICAN INSTITUTE OF STEEL CONSTRUCTION, INC.Seismic and Wind Applications Second EditionCopyright 2003byAmerican Institute of Steel Construction, I
3、nc.All rights reserved. This book or any part thereofmust not be reproduced in any form without thewritten permission of the publisher.The information presented in this publication has been prepared in accordance with recognizedengineering principles and is for general information only. While it is
4、believed to be accurate,this information should not be used or relied upon for any specific application without compe-tent professional examination and verification of its accuracy, suitability, and applicability bya licensed professional engineer, designer, or architect. The publication of the mate
5、rial containedherein is not intended as a representation or warranty on the part of the American Instituteof Steel Construction or of any other person named herein, that this information is suitable forany general or particular use or of freedom from infringement of any patent or patents. Anyonemaki
6、ng use of this information assumes all liability arising from such use.Caution must be exercised when relying upon other specifications and codes developed by otherbodies and incorporated by reference herein since such material may be modified or amendedfrom time to time subsequent to the printing o
7、f this edition. The Institute bears no responsi-bility for such material other than to refer to it and incorporate it by reference at the time of theinitial publication of this edition.Printed in the United States of AmericaFirst Printing: April 2004Revised: November 2009vAcknowledgementsAISC would
8、also like to thank the following people forassistance in the review of this Design Guide. Their com-ments and suggestions have been invaluable.Charles J. CarterJason R. EricksenLanny J. FlynnThomas FerrellSteve GreenChristopher M. HewittWilliam LiddyRonald L. MengDavis G. ParsonsWilliam T. SeguiVict
9、or ShneurScott UndershuteSergio ZorubaDesign procedures in this guide are primarily based onresearch conducted at the University of Oklahoma and atVirginia Polytechnic Institute. The research was sponsoredby the American Institute of Steel Construction, Inc.(AISC), the Metal Building Manufacturers A
10、ssociation(MBMA), the National Science Foundation, and the Fed-eral Emergency Management Administration (FEMA) SACSteel Project. AISC and MBMA member companies pro-vided test specimens. The work of former Oklahoma andVirginia Tech graduate students, Mary Sue Abel, MichaelR. Boorse, Jeffrey T. Borgsm
11、iller, David M. Hendrick,Timothy R. Mays, Ronald L. Meng, Scott J. Morrison, JohnC. Ryan and Ramzi Srouji made this guide possible. viiTable of Contents1. Introduction 11.1 Background 11.2 Overview of the Design Guide 21.3 Brief Literature Overview 21.3.1 End Plate Design 21.3.2 Bolt Design31.3.3 Co
12、lumn Side design 41.3.4 Cyclic test of End-Plate Moment Connections 51.3.5 Finite Element Analysis of End-Plate Moment Connections62. Background for Design Procedures 92.1 Basis of Design Recommendations 92.2 Overview of Theory and Mechanics 92.2.1 Connection Design Moment92.2.2 Yield Line Theory102
13、.2.3 Bolt Force Model 122.3 Limit State Check List142.4 Detailing and Fabrication Practices 143. Design Procedure 193.1 Overview 193.2 Design Steps193.3 Analysis Procedure 233.4 Limitations 244. Design Examples314.1 Scope 314.2 Four Bolt Unstiffened Extended (4E) End-Plate Connection 314.3 Four Bolt
14、 Stiffened Extended (4ES) End-Plate Connection 414.4 Eight Bolt Stiffened Extended (8ES) End-Plate Connection 43References 49Appendix A: Nomenclature53Appendix B: Preliminary Design Procedure and Design Aids 55DESIGN GUIDE 4, 2ND EDITION / EXTENDED END-PLATE MOMENT CONNECTIONSSEISMIC AND WIND APPLIC
15、ATIONS /11.1 BackgroundA typical moment end-plate connection is composed of asteel plate welded to the end of a beam section with attach-ment to an adjacent member using rows of fully tensionedhigh-strength bolts. The connection may join two beams(splice plate connection) or a beam and a column. end
16、-platemoment connections are classified as either flush orextended, with or without stiffeners, and further classifieddepending on the number of bolts at the tension flange. Aflush connection is detailed such that the end plate does notappreciably extend beyond the beam flanges and all boltsare loca
17、ted between the beam flanges. Flush end-plate con-nections are typically used in frames subject to light lateralloadings or near inflection points of gable frames. Anextended connection is detailed such that the end plateextends beyond the tension flange a sufficient distance toallow a location of b
18、olts other than between the beamflanges. Extended end plates may be used with or without astiffener between the end plate and the tension beam flangein the plane of the beam web. Extended end plates are usedfor beam-to-column moment connections.The three extended end-plate configurations shown inFig
19、ure 1.1 have been tested for use in seismic applications.The intent of this edition of the Guide is to present completedesign procedures and examples of the three moment end-plate configurations, which have been shown to be suitablefor fully constrained (FR or Type I) construction in seismicapplicat
20、ions. The design procedures can be used for otherthan seismic applications with proper adjustments for therequired connection design moment. The four-bolt unstiff-ened configuration shown in Figure 1.1(a) is probably themost commonly used in multi-story frame construction.Adding a stiffener as shown
21、 in Figure 1.1(b) can reduce therequired end plate thickness. Assuming the full beammoment strength is to be resisted and a maximum boltdiameter of 11/2 in., these connections, because of tensilebolt strength, will be sufficient for less than one-half of theavailable hot-rolled beam sections. The st
22、iffened eight-boltconnection shown in Figure 1.1(c) is capable of developingthe full moment capacity of most of the available beam sec-tions even if bolt diameter is limited to 11/2 in. Design pro-cedures and example calculations for these connections aregiven in the following chapters. Non-seismic
23、design procedures for the connection con-figurations shown in Figure 1.1(a) and (c) were presented inthe first edition of this guide (Murray 1990). These proce-dures are also found in the AISC ASD Manual of Steel Con-struction, 9th Edition (AISC 1989) and the LRFD Manualof Steel Construction, 3rd Ed
24、ition (AISC 2001). New design procedures for the configurations shown inFigure 1.1(a) and (b) plus seven other configurations areavailable in the American Institute of Steel Construc-tion/Metal Building Manufacturers Association SteelChapter 1Introduction(a) Four Bolt Unstiffened, 4E (b) Four Bolt S
25、tiffened, 4ES(c) Eight Bolt Stiffened, 8ESFig. 1.1. Extended end plate configurations.2 / DESIGN GUIDE 4 / EXTENDED END-PLATE MOMENT CONNECTIONSSEISMIC AND WIND APPLICATIONS, 2ND EDITIONDesign Guide 16 Flush and Extended Multiple-Row End-Plate Moment Connections (Murray and Shoemaker 2002).The desig
26、n procedures in Design Guide 16 permit the use ofsnug tightened bolts, but the procedures have not been ver-ified for high seismic applications.As with any connection, end-plate connections have cer-tain advantages and disadvantages. The principal advantages are:a) The connection is suitable for win
27、ter erection in thatonly field bolting is required.b) All welding is done in the shop, eliminating problemsassociated with field welding.c) Without the need for field welding, the erection processis relatively fast and generally inexpensive.d) If fabrication is accurate, it is easy to maintain plumb
28、-ness of the frame.e) Competitive total installed cost, for most cases.The principal disadvantages are:a) The fabrication techniques are somewhat stringentbecause of the need for accurate beam length and“squareness” of the beam end.b) Column out-of-squareness and depth tolerance can causeerection di
29、fficulties but can be controlled by fabricationof the beams 1/4 in. to 3/8 in. short and providing “finger”shims.c) End plates often warp due to the heat of welding.d) End plates are subject to lamellar tearing in the region ofthe top flange tension weld.e) The bolts are in tension, which can result
30、 in pryingforces.f) A portion of the stiffened end plate may extend abovethe finished floor requiring a larger column closure andreduced useable floor area.A number of designers and fabricators in the UnitedStates have successfully used moment end-plate connec-tions for building frames up to 30 stor
31、ies in height in lowseismic regions and up to 10 stories in height in high seis-mic regions. In spite of the several disadvantages, momentend-plate connections can provide economic solutions forrigid frame construction.1.2 Overview of the Design GuideThe remainder of this chapter is a brief survey o
32、f literaturepertinent to the recommended design procedures. Chapter 2presents the basic design procedures and recommendeddetailing and fabrication practices. Chapter 3 contains adesign procedure for all three connections. Chapter 4 hascomplete design examples. Nomenclature is found in theAppendix A.
33、 Appendix B has a preliminary design proce-dure and design aids.1.3 Brief Literature Overview There is a great deal of literature available on the analysisand design of end-plate moment connections. Publicationhas been almost continuous since the first known paper over40 years ago (Disque 1962). The
34、 1st Edition of this guidecontains a summary of the literature through the 1980s. Lit-erature, which is relevant to the scope of this edition, isbriefly summarized in the following five sub-sections: end-plate design, bolt design, column-side design, cyclic testingof end-plate moment connections, an
35、d finite element analy-sis of end-plate moment connections.1.3.1 End Plate DesignResearch starting in the early 1950s and continuing to thepresent has resulted in refined design procedures for bothflush and extended end-plate connections. The earlierdesign methods were based on statics and simplifyi
36、ngassumptions concerning prying forces. These methodsresulted in thick end plates and large diameter bolts. Otherstudies have been based on yield-line theory, the finite ele-ment method, and the finite element method together withregression analysis to develop equations suitable for designuse. The l
37、atter method was used to develop the design pro-cedures in the 1st Edition of this guide. The resulting designequations involve terms to fractional powers, which virtu-ally eliminates “structural feel” from the design. The designprocedures in this edition are based on yield-line theory andhave been
38、verified for use in high seismic regions by exper-imental testing. Reviews of relevant literature follows.Murray (1988) presented an overview of the past litera-ture and design methods for both flush and extended end-plate configurations, including column-side limit states.Design procedures, based o
39、n analytical and experimentalresearch in the United States, were presented. Murray (1990) presented design procedures for the four-bolt unstiffened, four-bolt wide unstiffened, and the eight-bolt extended stiffened end-plate moment connections. Theend plate design procedures were based on the works
40、ofKrishnamurthy (1978), Ghassemieh and others (1983), andMurray and Kukreti (1988).Chasten and others (1992) conducted seven tests on largeextended unstiffened end-plate connections with eight boltsDESIGN GUIDE 4, 2ND EDITION / EXTENDED END-PLATE MOMENT CONNECTIONSSEISMIC AND WIND APPLICATIONS /3at
41、the tension flange (four-bolts wide). Both snug and fullytensioned bolts were used in the testing. End-plate shearfractures, bolt fractures, and weld fractures were theobserved failure modes. Finite element modeling was usedto predict the distribution of the flange force to the tensionbolts and to p
42、redict the magnitude and location of the pry-ing force resultants. It was shown that the end-plate shearand bolt forces, including prying, can accurately be pre-dicted using finite element analysis. In addition, simpledesign rules that complemented the existing procedureswere presented.Graham (1993)
43、 reviewed the existing design methodsand recommended a limit state design method for the designof rigid beam-to-unstiffened column extended end-plateconnections.Borgsmiller and others (1995) conducted five tests onextended end-plate moment connections with large innerpitch distancesthe distance from
44、 the inside of the flangeto the first row of inside bolts. Results showing end plate,bolt, and connected beam behavior were presented.Borgsmiller (1995) presented a simplified method for thedesign of four flush and five extended end-plate momentconnection configurations. The bolt design procedure wa
45、s asimplified version of the modified Kennedy method (seeSection 2.2.3) to predict the bolt strength including theeffects of prying. The end plate strength was determinedusing yield line analysis. Fifty-two end-plate connectiontests were analyzed and it was concluded that the pryingforces in the bol
46、ts become significant when ninety percentof the yield-line end plate strength is achieved. This estab-lished a threshold for the point at which prying forces in thebolts can be neglected. If the applied load is less than ninetypercent of the plate strength, the end plate is considered tobe thick and
47、 no prying forces are considered; when theapplied load is greater than ninety percent of the end platestrength, the end plate is considered to be thin and the pry-ing forces are assumed to be at a maximum. This distinctthreshold between thick and thin plate behavior greatlysimplified the bolt force
48、determination because only thecase of no prying or maximum prying must be determined.Good correlation with past test results was obtained usingthe simplified design procedure.Sumner and Murray (2001a) performed six, three rowextended end-plate connection tests to investigate the valid-ity of the cur
49、rent design procedures for gravity, wind andlow seismic loading. In addition, the tests investigated theeffects of standard and large inner pitch distances and theconnections utilized both ASTM A325 and ASTM A490bolts. Good correlation between the experimental and ana-lytical results was observed.Sumner and Murray (2001b) investigated extended end-plate connections with four high strength bolts per rowinstead of the traditional two bolts per row. The eight-boltextended, four-bolts wide and three row extended, four-bolts wide end-plate moment connections were investi-gated. Seven
