Table Of ContentThis is an electronic version of the print textbook. Due to electronic rights restrictions, some third party content may
be suppressed. Editorial review has deemed that any suppressed content does not materially affect the overall
learning experience. The publisher reserves the right to remove content from this title at any time if subsequent rights
restrictions require it. For valuable information on pricing, previous editions, changes to current editions, and
alternate formats, please visit www.cengage.com/highered to search by ISBN#, author, title, or keyword for
materials in your areas of interest.
Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.
1019763_FM_VOL-I.qxp 9/17/07 4:22 PM Page viii
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
S 50
R 51
1st Pass Pages
1019763_FM_VOL-I.qxp 9/17/07 4:22 PM Page viii
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
S 50
R 51
1st Pass Pages
AFirstCourseintheFiniteElementMethod, (cid:2)c 2012CengageLearning
FifthEdition
ALLRIGHTSRESERVED.Nopartofthisworkcoveredbythecopyright
DarylL.Logan
hereinmaybereproduced,transmitted,stored,orusedinanyformorby
Publisher,GlobalEngineering: anymeansgraphic,electronic,ormechanical,includingbutnotlimitedto
ChristopherM.Shortt photocopying,recording,scanning,digitizing,taping,Webdistribution,
informationnetworks,informationstorageandretrievalsystems,exceptas
SeniorAcquisitionsEditor:RandallAdams
permittedunderSection107or108ofthe1976UnitedStatesCopyright
SeniorDevelopmentalEditor: Act,withoutthepriorwrittenpermissionofthepublisher.
HildaGowans
EditorialAssistant:TanyaAltieri Forproductinformationandtechnologyassistance,
TeamAssistant:CarlyRizzo contactusatCengageLearningCustomer&
SalesSupport,1-800-354-9706
MarketingManager:LaurenBetsos
Forpermissiontousematerialfromthistextorproduct,
MediaEditor:ChrisValentine
submitallrequestsonlineatwww.cengage.com/permissions
ContentProjectManager:D.JeanButtrom Furtherpermissionsquestionscanbeemailedto
ProductionService: permissionrequest@cengage.com
RPKEditorialServices,Inc.
Copyeditor:ShellyGerger-Knechtl LibraryofCongressControlNumber:2010938463
Proofreader:BeckyTaylor ISBN-13:978-0-495-66825-1
Indexer:ShellyGerger-Knechtl ISBN-10:0-495-66825-7
Compositor:GlyphInternational
SeniorArtDirector:MichelleKunkler
CengageLearning
CoverDesigner:AndrewAdams
200FirstStamfordPlace,Suite400
CoverImage:CourtesyofValmontWest Stamford,CT06902
CoastEngineering USA
InternalDesigner:CarmelaPeriera
SeniorRights,AcquisitionsSpecialist: CengageLearningisaleadingproviderofcustomizedlearningsolutions
MardellGlinski-Schuttz withofficelocationsaroundtheglobe,includingSingapore,theUnited
TextandImagePermissionsResearcher: Kingdom,Australia,Mexico,Brazil,andJapan.Locateyourlocalofficeat:
KristiinaPaul international.cengage.com/region.
FirstPrintBuyer:AretheaL.Thomas
CengageLearningproductsarerepresentedinCanadabyNelson
EducationLtd.
Foryourcourseandlearningsolutions,visit
www.cengage.com/engineering
Purchaseanyofourproductsatyourlocalcollegestoreoratourpreferred
onlinestorewww.cengagebrain.com
PrintedintheUnitedStatesofAmerica
123456713121110
Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.
A F C
IRST OURSE
F
IN THE INITE
E M d
LEMENT ETHOD
Fifth Edition
Daryl L. Logan
University of Wisconsin–Platteville
Australia • Brazil • Japan • Korea • Mexico • Singapore • Spain • United Kingdom • United States
Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.
d
C
ONTENTS
Preface xi
1 Introduction 1
ChapterObjectives 1
Prologue 1
1.1 BriefHistory 2
1.2 IntroductiontoMatrixNotation 4
1.3 RoleoftheComputer 6
1.4 GeneralStepsoftheFiniteElementMethod 7
1.5 ApplicationsoftheFiniteElementMethod 15
1.6 AdvantagesoftheFiniteElementMethod 23
1.7 ComputerProgramsfortheFiniteElementMethod 25
References 27
Problems 29
2 Introduction to the Stiffness (Displacement) Method 31
ChapterObjectives 31
Introduction 31
2.1 DefinitionoftheSti¤nessMatrix 32
2.2 DerivationoftheSti¤nessMatrixforaSpringElement 32
2.3 ExampleofaSpringAssemblage 38
2.4 AssemblingtheTotalSti¤nessMatrixbySuperposition
(DirectSti¤nessMethod) 40
2.5 BoundaryConditions 42
2.6 PotentialEnergyApproachtoDeriveSpringElementEquations 56
SummaryEquations 65
References 66
Problems 66
iii
Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.
iv d Contents
3 Development of Truss Equations 72
ChapterObjectives 72
Introduction 72
3.1 DerivationoftheSti¤nessMatrixforaBarElement
inLocalCoordinates 73
3.2 SelectingApproximationFunctionsforDisplacements 79
3.3 TransformationofVectorsinTwoDimensions 82
3.4 GlobalSti¤nessMatrixforBarArbitrarilyOrientedinthePlane 85
3.5 ComputationofStressforaBarinthex-yPlane 90
3.6 SolutionofaPlaneTruss 92
3.7 TransformationMatrixandSti¤nessMatrixforaBar
inThree-DimensionalSpace 100
3.8 UseofSymmetryinStructure 109
3.9 Inclined,orSkewed,Supports 112
3.10 PotentialEnergyApproachtoDeriveBarElementEquations 118
3.11 ComparisonofFiniteElementSolutiontoExactSolutionforBar 129
3.12 Galerkin’sResidualMethodandItsUsetoDerivetheOne-Dimensional
BarElementEquations 133
3.13 OtherResidualMethodsandTheirApplicationtoaOne-Dimensional
BarProblem 136
3.14 FlowchartforSolutionofThree-DimensionalTrussProblems 141
3.15 ComputerProgramAssistedStep-by-StepSolutionforTrussProblem 141
SummaryEquations 144
References 145
Problems 146
4 Development of Beam Equations 166
ChapterObjectives 166
Introduction 166
4.1 BeamSti¤ness 167
4.2 ExampleofAssemblageofBeamSti¤nessMatrices 177
4.3 ExamplesofBeamAnalysisUsingtheDirectSti¤nessMethod 179
4.4 DistributedLoading 192
4.5 ComparisonoftheFiniteElementSolutiontotheExactSolution
foraBeam 205
4.6 BeamElementwithNodalHinge 211
Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.
Contents d v
4.7 PotentialEnergyApproachtoDeriveBeamElement
Equations 218
4.8 Galerkin’sMethodforDerivingBeam
ElementEquations 221
SummaryEquations 223
References 224
Problems 225
5 Frame and Grid Equations 235
ChapterObjectives 235
Introduction 235
5.1 Two-DimensionalArbitrarilyOrientedBeamElement 235
5.2 RigidPlaneFrameExamples 239
5.3 InclinedorSkewedSupports—FrameElement 258
5.4 GridEquations 259
5.5 BeamElementArbitrarilyOrientedinSpace 277
5.6 ConceptofSubstructureAnalysis 290
SummaryEquations 296
References 298
Problems 299
6 Development of the Plane Stress
and Plane Strain Stiffness Equations 328
ChapterObjectives 328
Introduction 328
6.1 BasicConceptsofPlaneStressandPlaneStrain 329
6.2 DerivationoftheConstant-StrainTriangularElement
Sti¤nessMatrixandEquations 334
6.3 TreatmentofBodyandSurfaceForces 349
6.4 ExplicitExpressionfortheConstant-Strain
TriangleSti¤nessMatrix 354
6.5 FiniteElementSolutionofaPlaneStressProblem 356
6.6 RectangularPlaneElement(BilinearRectangle,Q4) 367
SummaryEquations 373
References 376
Problems 377
Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.
vi d Contents
7 Practical Considerations in Modeling;
Interpreting Results; and Examples
of Plane Stress–Strain Analysis 384
ChapterObjectives 384
Introduction 384
7.1 FiniteElementModeling 385
7.2 EquilibriumandCompatibilityofFiniteElementResults 398
7.3 ConvergenceofSolution 402
7.4 InterpretationofStresses 405
7.5 StaticCondensation 407
7.6 FlowchartfortheSolutionofPlaneStress–StrainProblems 411
7.7 ComputerProgram-AssistedStep-by-StepSolution,OtherModels,
andResultsforPlaneStress–StrainProblems 411
References 417
Problems 420
8 Development of the Linear-Strain Triangle Equations 437
ChapterObjectives 437
Introduction 437
8.1 DerivationoftheLinear-StrainTriangularElement
Sti¤nessMatrixandEquations 437
8.2 ExampleLSTSti¤nessDetermination 442
8.3 ComparisonofElements 445
SummaryEquations 448
References 448
Problems 449
9 Axisymmetric Elements 452
ChapterObjectives 452
Introduction 452
9.1 DerivationoftheSti¤nessMatrix 452
9.2 SolutionofanAxisymmetricPressureVessel 463
9.3 ApplicationsofAxisymmetricElements 469
SummaryEquations 474
References 476
Problems 476
Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.