T.Chhay




               Appendix A. karKNna              nigkarviPaKedaylkçN³)aøsÞic
                                Plastic Analysis and Design
A >1> esckþIepþIm Introduction
        eyIg)anENnaMBIKMniténkar)ak;eday)aøsÞic (plastic collapse) enAkñúgEpñk 5>2/ “ kugRtaMg
Bt; nigm:Um:g)aøsÞic” . kar)ak;rbs;eRKOgbgÁúMnwgekIteLIgenAeBlbnÞúkbegáItsnøak;)aøsÞicRKb;RKan;edIm,I
             ;
begáItCa mechanism EdlnwgeFVIeGaymanPaBdabedayminmankarekIneLIgbnÞúk. enAkñúgFñwmEdl
kMNt;edaysþaTic eKRtUvkarEtsnøak;)aøsÞicmYyEtb:ueNÑaH. dUcbgðajenAkñúgrUbTI A>1 snøak;nwgekIt
manenAkEnøgNaEdlmanm:Um:g;Gtibrma ¬krNIenHKWenAkNþalElVg¦. enAeBlEdlm:Um:g;Bt;mantMél
FMRKb;RKan;edIm,IeFVIeGaymuxkat;TaMgmUl yield/ enaHvaminGacTb;nwgkarekIneLIgrbs;m:Um:g;EfmeTot/
ehIysnøak;)aøsÞick¾RtUv)anbegáIteLIg. snøak;)aøsÞicenHRsedogKñanwgsnøak;FmμtaEdr EtxusRtg;fa
snøak;)aøsÞicmanlT§PaBTb;nwgm:m:g;xøH EdldUcKñay:agxøaMgnwg rusty hinge.
                                U




                                             460                                         Appendix A
NPIC




lT§PaBm:Um:g;)aøsÞic (plastic moment capacity) EdlsMKal;eday M p Cam:Um:g;Bt;EdlekIt
manenARtg;snøak;)aøsÞic. vamantMélesμInwgm:Um:g;Tb;xagkñúgEdlekItBIkarEbgEckkugRtaMgEdlbgðaj
enAkñúgrUbTI A>1 c EtmanTisedApÞúyKña. eKGackMNt;m:Um:g;)aøsÞicenAeBlEdleKsÁal; yield stress
nigrUbragmuxkat; dUcbgðajenAkñúgrUbTI A>2. RbsinebIkarEbgEckkugRtaMgenAkñúglkçxNÐ)aøsÞiceBj
RtUv)anCMnYsedaykMlaMgsmmUlsþaTicBIrEdlmantMéldUcKña nigTisedApÞúyKña enaHvanwgbegáIt couple.
GaMgtg;sIueténkMlaMgnImYy²esμInwgplKuNrvag yield stress nigBak;kNþalRkLaépÞmuxkat;srub.
m:Um:g;EdlbegáIteday couple xagkñúgenHKW
                  A
       M p = Fy     a = Fy Z x
                  2
Edl A CaRkLaépÞmuxkat;srub/ a CacMgayrvagTIRbCMuTMgn;énRkLaépÞBak;kNþalBIr nig Z x Cam:U
Dulmuxkat;)aøsÞic. emKuNsuvtßiPaBcenøaHsßanPaB yielding dMbUg nigsßanPaB)aøsÞiceBjRtUv)ansM
EdgenAkñúgm:UDulmuxkat;. BIrUbTI A>1 b eKGacsresrm:Um:g;EdlbegáIt yield dMbUg
                          M p Fy Z x Z x
       M y = Fy S x nig         =       =
                          M y     F S
                                 y x     xS

pleFobenHCatMélefrsMrab;rUbragmuxkat;EdlsÁal; nigRtUv)aneKehAfa emKuNrUbrag. sMrab;Fñwm
EdlKNnaeday allowable stress theory vaCargVas;én reserve capacity ehIymantMélmFüm 1.12
sMrab; W-shapes.




        enAkñúgFñwm b¤eRKagsþaTicminkMNt; eKRtUvkarsnøak;)aøsÞiceRcInCagmYyedIm,IbegáIt collapse
mechanism. snøak;TaMgenHnwgRtUv)anbegáIttamlMdab;lMeday eTaHbICaeKmincaM)ac;dwgBIlMdab;k¾eday.

eKnwgBicarNakarviPaKrcnasm<n§½sþaTicminkMNt;eRkayBIkarBiPakSatMrUvkarrbs; Specification.


                                             461                                   Appendix A
T.Chhay




A>2>   AISC Requirements

       AISC Specification      GnuBaØatieGayeRbI plastic analysis and design enAeBl eRKOg
bgÁúMenArkSaPaBlMnwgTaMg local nigTaMgmUl Rtg;cMnuc plastic collapse. edaysareKtMrUveGayFñwm
b¤eRKagrgnUvPaBdabFMenAeBlEdlsnøak;)aøsÞicRtUv)anbegáIt eKRtUvkar lateral bracing CaBiess.
         edIm,IkarBar local buckling, AISC B5.2 TamTarfaGgát;man compact cross-sectional
shape Edl λ ≤ λ p sMrab;TaMgRTnug nigsøab. sMrab;Ggát; I-shaped shape dUcCa W nig S-shapes

pleFobTTwgelIkMras;EdlkMNt;BI Table B5.2 KW
        bf         65             bf         170
              ≤           (US)           ≤           (IS)
       2t f        Fy             2t f        Fy

nig     h
       tw
          ≤
            640
             Fy
                          (US)
                                   h 1680
                                  tw
                                     ≤
                                       Fy
                                                     (IS)


       edIm,IkarBar lateral buckling, AISC F1.2d kMNt; unbraced length Gtibrma       Lb   Rtg;
TItaMgsnøak;)aøsÞicCa L pd EdlsMrab; I-shaped member
                  3600 + 2200(M 1 / M 2 )
       L pd =                             ry         (US)         (AISC Equation F1-17)
                           Fy
                  24820 + 15170(M 1 / M 2 )
       L pd =                               ry       (IS)
                            Fy

enAkñúgsmIkarenH M 1 Cam:Um:g;EdltUcCagenARtg;cugén unbraced length nig M 2 CamU:m:g;EdlFMCag.
pleFob M 1 / M 2 KwviC¢manenAeBlEdl M 1 nig M 2 Bt;Ggát;eGaymankMeNagDub nigmantMél
GviC¢manenAeBlEdlvabegáItkMeNageTal.
        sMrab; compact shape Edlman lateral bracing RKb;RKan; eKGacyk M n esμInwg M p sMrab;
eRbIenAkñúg plastic analysis. b:uEnþ AISC F1.2d kMNt;faenAkñúgtMbn;EdlekItmansnøak;)aøsÞiccug
eRkay nigenAkñúgtMbn;EdlminEk,rsnøak;)aøsÞic eKRtUveRbIviFIFmμtaedIm,IkMNt; M n .
        AISC Specification provision epSgeTotEdlTak;Tgnwg plastic analysis and design

mandUcxageRkam.
        A5.1 Plastic analysis RtUv)anGnuBaØatsMrab;Et Fy ≤ 65ksi .

        C2.2 kMlaMgtamG½kSEdlbegáItedaybnÞúkTMnajemKuN nigbnÞúktamTisedkemKuNminRtUvFM

                Cag 0.75φc Ag Fy .

                                                   462                            Appendix A
NPIC




       E1.2   sMrab;ssr slenderness parameter λc minRtUvFMCag 1.5K Edl K CaemKuNRbEvg
              RbsiT§PaB.
A >3> karviPaK Analysis
RbsinebIvaGacman collapse mechanism eRcInCamYy dUcCaFñwmCab;EdlbgðajenAkñúgrUbTI A>3
eKGacrk)annUv collapse mechanism EdlRtwmRtUv ehIyviPaKCamYynwgCMnYyénRTwsþIeKalcMnYnbIrbs;
plaxtic analysis EdleGayenATIenHedayKμankarRsaybBa¢ak;.




       !>   Lower-bound    theorem    (static    theorem):    RbsinebIeKGacrk)annUvkarEbgEck
          m:Um:g;d¾mansuvtßiPaB ¬Edlm:Um:g;mYytUcCag b¤esμInwg M p RKb;kEnøg¦ ehIyvaGacTTYl
          bnÞúkedaysþaTic ¬lMnwgRtUv)anbMeBj¦ bnÞab;mkbnÞúkEdlRtUvKñaRtUvtUcCag b¤esμI
          collapse load.

       @> Upper-bound theorem (kinetic theorem): bnÞúkEdlRtUvnwg mechanism snμt;RtUvEtFM
          Cag b¤esμInwg collapse load. Cavi)ak RbsinebIeKGegát mechanism EdlGacmanTaMg
          Gs; mechanism mYyNaEdlRtUvkarbnÞúktUcCageKCa mechanism EdlRtwmRtUv.
       #> Uniqueness theorem: RbsineKmankarEbgEckm:Um:g;EdlGacTTYlyk)anedaysþaTic
          nigmansuvtßiPaB EdlenAkñúgenaH snøak;)aøsÞicRKb;RKan;begáIt collapse mechanism enaH


                                           463                                   Appendix A
T.Chhay




            bnÞúkEdlRtUvKñaCa collapse load EdlRbsinebI mechanism bMeBjTaMg upper-boud
            theorem nig lower-bound theorem vaCa mechanism EdlRtwmRtUv.

karviPaKEdlQrelI lower-bound theorem RtUv)aneKehAfa equilibrium method ehIyRtUv)an
bgðajenAkñúg]TahrN_ A>1.

]TahrN_ A>1³ rkbnÞúkcugeRkay      (ultimate load) sMrab;FñwmEdlbgðajenAkñúgrUbTI A>4a eday
equilibrium method rbs; plastic analysis. snμt;eKeRbI continuous lateral support nig EdlRb

ePT A36 .




dMeNaHRsay³ Edk A36 muxkat; W 30 × 99 Ca comapact shape ehIyCamYynwg continuous lateral
support, tMrUvkar lateral bracing KWRKb;RKan; dUcenHeKGacTTYlyk plastic analysis.
        dMNak;karénkardak;bnÞúkelIFñwm BI working load eTAdl; collapse load
RtUv)anKUsbBa¢ak;enAkñúgrUbTI A>4a-d. enAeBl working load muneBl yielding ekIteLIgRKb;TIkEnøg
karEbgEckm:Um:g;Bt;RtUv)anbgðajenAkñúgrUbTI A>4a CamYynwgm:Um:g;GtibrmaEdlekItmanRtg;TMrbgáb;.
enAeBlEdlbnÞúkekIneLIgbnþicmþg² yielding cab;epþImekItmanRtg;TMr enAeBlEdlm:Um:g;Bt;eTAdl;
M y = Fy S x . enAeBlEdlbnÞúkekIneLIgkan;EtFM vanwgekItmansnøak;)aøsÞickñúgeBldMNalKñaenA

Rtg;cugnImYy² enAeBlEdl M p = Fy Z x . enARtg;kMrwténkardak;bnÞúkenH eRKOgbgÁúMenAmanesßrPaB

                                          464                                      Appendix A
NPIC




enAeLIy FñwmRtUv)anERbkøayeTACasþaTickMNt;edaykarekItmansnøak;)aøsÞicBIr. Mechanism nwgekIt
anEtenAeBlEdlekItmansnøak;)aøsÞicTIbI. vaGacekItmanenAeBlEdlm:Um:g;viC¢manGtibrmamantMél
 M p . edayGaRs½ynwg uniqueness theorem/ bnÞúkEdlRtUvKñaCa collapse load BIeRBaHkarEbgEck

m:Um:g;KWsuvtßiPaB ehIyGacTTYlyk)anedaysþaTic.
          enARKb;tMNak;kalénkardak;bnÞúk plbUkénéldac;xaténm:Um:g;viC¢man nigm:Um:g;GviC¢manGti-
brmaKW wL2 / 8 . enAeBl collapse, plbUkenHkøayeTACa
                                              16M p
          M p + M p = wu L2 b¤
                       1
                                        wu =
                       8                        L2
eKRtUvEteRbobeFobbnÞúkemKuNCamYynwgersIusþg;emKuN dUcenHeKeRcIneRbI φb M p Cag M p enAkñúg
smIkarBIxagedIm. b:uEnþedIm,IrkSanimitþsBaØaeGaymanlkçN³samBaØ eyIgeRbI M p enARKb;]TahrN_
TaMgGs;rhUtdl;CMhancugeRkayeTIbeyIgCMnYs φb M p eTAkñúgsmIkar. lT§plEdlRtwmRtUv
sMrab;]TahrN_enHKW
                  16φb M p
        wu =
                     L2
sMrab; W 30 × 99
                             36(312 )
        M p = Fy Z x =                = 936 ft − kips
                               12
ehIy φb M p = 0.9(936) = 842.4 ft − kips
eKk¾GacTTYltMélrbs; φb M p edaypÞal;BI Load Factor Design Selection Table enAkñúg Part 4 of
the Manual.
                  16(842.4 )
cemøIy³ w u   =
                    (30)2
                               = 15.0kips / ft



]TahrN_ A>2³RbsinebIFñwmenAkñúg]TahrN_ A>1 minman continuous lateral support cUrkMNt;TItaMg
EdlRtUvBRgwg.
dMeNaHRsay³ snøak;)aøsÞicenAxagcugekIteLIgkñúgeBldMNalKña ehIymuneBlsnøak;enAkNþalElVg
ekIteLIg. dUcenHeKKYrEtRtYtBinitü unbraced length GtibrmaedayeFobeTAnwgcug ¬snøak;cugeRkay
EdlekIteLIgmintMrUvkar bracing sMrab; plastic analysis eT¦.



                                                   465                              Appendix A
T.Chhay




       edayeFobnwgsnøak;enAcugxageqVg snμt;facMnucBRgwgKWenAkNþalElVg. kñúgkrNIenH M 1 =
M 2 = M p dUcenHFñwmmankMeNagDub ¬m:Um:g;TaMgBIrmansBaØadUcKña¦ dUcenH M 1 / M 2 = +1 BI AISC

Equation F1-17, unbraced length GtibrmaKW
                 3600 + 2200(M 1 / M 2 )      3600 + 2200(1.0)
        L pd =                           ry =                  (2.10) = 338.3in. = 28.2 ft
                          Fy                         36

cMNaMfa FñwmenHesÞIrEtRKb;RKan;edayminRtUvkar lateral bracing.
        CamYynwg lateral mYyTl;enAkNþalElVg
        L p = 15 ft < 28.2 ft    (OK)

Unbraced length       EdlRtUvBicarNarYmKWrYbbBa©ÚlTaMgsnøak;enAkNþalElVg. vaminmantMbn;Edlmin
enACab;nwgsnøak;)aøsÞiceT dUcenHvaminRtUvkarkarKNna design strength eT.
cemøIy³ eRbI lateral brace mYyenAkNþalElVg.

       Mechanism method          KWQrelI    upper-bound theoremnigRtUvakrGegátRKb; collapse
mechanism EdlGacekItman. Collapse mechanism NaEdlRtUvkarbnÞúktUcCageKnwglub eyIy

bnÞúkEdlRtUvKñaCa collapse laod. eKRtUvGnuvtþeKalkarN_rbs; virtual work sMrab;viPaK
mechanism nImYy². Mechanism snμt;RtUvrgnUv virtual displacement RsbeTAtamclnaEdl

GacekItmanrbs; mechanism ehIyeKeGaykmμnþxageRkA nigkmμnþxagkñúgesμIKña. bnÞab;mkeKGacrk
TMnak;TMngrvagbnÞúk niglT§PaBTb;m:Um:g;)aøsÞic M p . bec©keTsenHRtUv)anbgðajenAkñúg]TahrN_
A>3 nig A>4.



]TahrN_ A>3³ FñwmCab;EdlRtUv)anbgðajenAkñúgrUbTI A>5 man compact cross section Edlman
design strength φb M p = 1040 ft − kips    . eRbI mechanism method edIm,Irk collapse load Pu .
snμt; continuous lateral support.
dMeNaHRsay³ eKman failure mechanism sMrab;FñwmenHBIry:ag. dUcEdlbgðajenAkñúgrUbTI A>5
vamanlkçN³RsedogKñaEdlkMNat;Ggát;nImYy²rgnUv rigid-body motion. edIm,IGegát mechanism
enAkñúgElVg AB dak; vitual rotation θ Rtg; A. karvilEdlRtUvKñaenARtg;snøak;)aøsÞicRtUv)anbgðaj
enAkñúgrUbTI A>5b ehIybMlas;TItamTisQrébnÞúkKW 10θ . BIeKalkarN_rbs; virtual work
         kmμnþxageRkA = kmμnþxagkñúg
                                              466                                        Appendix A
NPIC




        P(10θ ) = M p (2θ ) + M pθ

¬vaminmankmμnþxagkñúgenARtg; A eT eRBaHvaminmansnøak;)aøsÞic¦
       collapse load KW
                 3M p
        Pu =
                  10
Mechanism   sMrab;ElVg AB manlkçN³xusKñabnþic³ RKb;snøak;TaMgbICasnøak;)aøsÞic.
Virtual work xagkñúg nig virtual work xageRkAkñúgkrNIKW

        2 Pu (15θ ) = M pθ + M p (2θ ) + M pθ

enaH Pu = 15 M p
             2


lT§PaBTIBIrenHRtUvkarbnÞúktUcCag dUcenHvaCa mechanism EdlRtwmRtUv. Collapse load Edlnwg
TTYl)anedayeRbI φb M p CMnYseGay M p
cemøIy³ Pu   =
                  2
                 15
                    φb M p = (1040) = 139kips
                             2
                            15




                                                467                               Appendix A
T.Chhay




]TahrN_ A>4³ kMNt; collapse load P sMrab; rigid frame EdlbgðajenAkñúgrUbTI A>6. Ggát;
                                      u

nImYy²rbs;eRKagKW W 21×147 Edlman Fy = 50ksi . snμt; lateral support Cab;.




dMeNaHRsay³ W 21×147 Ca compact shape sMrab; F      y   = 50ksi   nigman lateral support Cab; dUc
enHvabMeBjlkçxNÐkñúgkareRbIR)as; plastic analysis.
        dUcbgðajenAkñúgrUbTI A>6 eKman failure mode cMnYnbIsMrab;eRKagenH³ Fñwm mechanism enA
kñúgGgát; BC / sway mechanism nigmYyeTotCabnSMén mechanism BIrdMbUg. eyIgcab;epþImkarviPaK
mechanism nImYy²edaydak; virtual rotation θ enARtg;snøak;mYy ehIysresrsmIkarCaGnuKmn_

eTAnwgmMuenH.

                                          468                                         Appendix A
NPIC




       Virtual displacement    rbs;Fñwm mechanism RtUv)anbgðajenAkñúgrUbTI A>6 b. BIsmPaBén
kmμnþxageRkA nigkmμnþxagkñúg
                               ⎛5 ⎞        ⎛2 ⎞
        Pu (10θ ) = M pθ + M p ⎜ θ ⎟ + M p ⎜ θ ⎟
                               ⎝3 ⎠        ⎝3 ⎠
EdleKeRbI M p CMnYseGay φb M p . edaHRsayrk Pu
        Pu = 0.3333M p

RbsinebIeKminKit axial strain enAkñúgGgát; BC / sway mechanism nwgxUcRTg;RTaydUcbgðaj
enAkñúgrUbTI A>6 c CamYynwgbMlas;TItamTisedkdUcKñaRtg; B nig C . Cavi)ak muMrgVilénRKb;snøak;
TaMgGs;KWlkçN³RsedogKña³
          Pu (15θ ) = M p (4θ ) b¤   Pu = 0.2667 M p

BIrUbTI A>6d/ eKalkarN_én virtual work sMrab; combined mechanism eGay
                                           ⎛5 ⎞        ⎛2      ⎞
        Pu (15θ ) + Pu (10θ ) = M pθ + M p ⎜ θ ⎟ + M p ⎜ θ + θ ⎟ + M pθ
                                           ⎝3 ⎠        ⎝3      ⎠
        Pu = 0.2133M p         ¬lub¦
cemøIy³ Collapse load sMrab;eRKagKW Pu = 0.2133φb M p = 0.2133(1400) = 299kips

         cMNaMfa vamancMnucdUcKñaxøHrvagviFIénkarviPaKTaMgBIr. eTaHbICa equilibrium method
minRtUvkarBicarNaRKb; mechanism k¾eday k¾vaRtUvkareGayeyIgdwgBI mechanism enAeBlEdlkar
EbgEcgm:Um:g;snμt;RsbeTAnwg mechanism mYy. viFITaMgBIrRtUvkarkarsnμt; failure mechanism b:uEnþ
enAkñúg equilibrium method eKRtUvRtYtBinitükarsnμt;nImYy²sMrab;suvtßiPaB nigkarEbgEckm:Um:g;Edl
GacTTYlyk)anedaysþaTic ehIyvaminRtUvkarkarGegátRKb; mechanism eT.
A >4> karKNnamuxkat; Design
       dMeNIrkarénkarKNnaKWRsedogKñanwgkarviPaKEdr EtvaxusKñaRtg;faGBaØtiEdlRtUvrkCalT§
PaBm:Umg;)aøsÞicEdlRtUvkar M p . eKsÁal; collapse load EdlTTYl)anBIkarKuN service load nwgem
KuNbnÞúk.

]TahrN_ A>4³ FñwmCab;bIElVgdUcbgðajenAkñúgrUbTI A>7 RtUvRTnUv gravity service load. bnÞúknI-
mYy²pSMeLIgedaybnÞúkefr 25% nigbnÞúkGefr 75% . eKeRbI cover plate enAkñúgElVg BC nig CD
                                             469                                   Appendix A
T.Chhay




edIm,ITTYl)an moment strength dUcEdl)anbgðaj. snμt; continuous lateral support nigeRCIs
erIsrUbragEdksMrab;RbePT A36 .




dMeNaHRsay³ Collapse load EdlTTYl)anedaykarKuN service load edayemKuNbnÞúksmRsb.
sMrab; service load 45kips
        Pu = 1.2(0.25 × 45) + 1.60(0.75 × 45) = 67.5kips
sMrab; service load 75kips
        Pu = 1.2(0.25 × 75) + 1.60(0.75 × 75) = 85.5kips
eKRtUvGegát          bIEdlman mechanism mYyenAelIElVgmYy. rUbTI A>7 c-e bgðajBI
              mechanism

mechanism nImYy²eRkayBIrgnUv virtual displacement. enAeBlEdlsnøak;)aøsÞicekIteLIgenARtg;




                                            470                               Appendix A
NPIC




TMrEdlGgát;nImYy²minmanersIusþg;esμIKña vanwgekIteLIgenAeBlEdlm:Um:g;Bt;esμInwglT§PaBm:Um:g;)aøsÞic
rbs;Ggát;EdlexSayCag.
          sMrab;ElVg AB
                  kmμnþxageRkA = kmμnþxagkñúg
                  67.5(5θ ) = M p (2θ + θ )        b¤ M p = 112.5 ft − kips
          sMrab;ElVg BC
                  85.5(10θ ) = M pθ + 2M p (2θ ) + M pθ
                                                     5
                                                     3
                                                                  b¤ M p = 128.2 ft − kips
          sMrab;ElVg CD
                  85.5(10θ ) = M p (θ + 2θ + θ )
                               5
                               3
                                                          b¤ M p = 128.2 ft − kips
Upper-bound theorem RtUv)anbkRsaydUcxageRkam³ tMélénm:Um:g;)aøsÞicEdlRtUvKñanwg mechanism

Edlsnμt;KWtUcCag b¤esμInwgm:Um:g;)aøsÞicsMrab; collapse load. dUcenH mechanism EdlTamTarlT§PaB
m:Um:g;FMCageKCa mechanism EdlRtwmRtUv. Mechanism TaMgBIrcugeRkaymantMél M p dUcKña ehIy
GacnwgekIteLIgkñúgeBldMNalKña. CaTUeTAersIusþg;EdlRtUvkarCa design strength EdlRtUvkar dUc
enH
         φb M p = 128.2 ft − kips
BI   Load Factor Design Selection Table,       rUbragEdlRsalCageKKW W 16 × 31 Edlman        design
strength θ b M p = 146 ft − kips

         sakl,g W 16 × 31 ehIyRtYtBinitükMlaMgkat; ¬eyagtamrUbTI A>8¦
         sMrab;ElVg AB
                 ∑ M B = V A (10 ) − 67.5(5) + 128.2 = 0

                V A = 20.93kips

                VB = 20.93 − 67.5 = −46.57 kips
         sMrab;ElVg BC
                                           ⎛5⎞
                ∑ M B = − M p + 85.5(10) + ⎜ ⎟ M p − VC (20) = 0
                                           ⎝3⎠
                     85.5(10) + (2 / 3)M p 855 + (2 / 3)(128.2)
                VC =                      =                     = 47.02kips
                              20                    20
                VB = 85.5 − 47.02 = 38.48kips



                                               471                                     Appendix A
T.Chhay




       sMrab;ElVg CD
                ∑ M C = − M p + M p + 85.5(10) − VD (20) = 0
                         5     5
                         3     3
               VD = 42.75kips = VC
        dUcenH kMlaMgkat;TTwgGtibrma VC KW)anmkBIElVg BC b¤esμIKña 47.02kips .
        BItaragbnÞúkBRgayesμIemKuNenAkñúg Part 4 of the Manual, shear design strength rbs;
W 16 × 31 KW
        φvVn = 84.9kips > 47.02kips         (OK)
cemøIy³ eRbI W 16 × 31 .

A >5> karsnñidæan Conclusion Remark
        karviPaKén mechanism EdlrgbnÞúkBRgaybgðajBIPaBsμúKsμajbEnßmeTotEdlmin)anerob
rab;enATIenH. bBaðaCak;EsþgenAkñúg plastic analysis or design rYmbBa©ÚlnUvkardak;bnÞúkEbbenH
y:agCak;Esþg. elIsBIenH eKKYrGegátGnþrGMeBIénT§iBlrbs;kMlaMgtamG½kS nigm:Um:g;Bt;sMrab;Ggát;
EdlrgTaMgkMlaMgtamG½kS nigm:Um:g;Bt; dUcenA rigid frame enAkñúg]TahrN_ A>4 .
        cMeBaHviFIviPaKEdlmanlkçN³TUeTAdUcCa equilibrium method manniyayy:aglMGitenAkñúg
the plastic methods of structural analysis (Neal, 1977). ehIyvamanrUbmnþEdlman

lkçN³sμúKsμajsMrab; mechanism method eTotpg. CamYynwgviFIenH EdleKsÁal;faCa method of
inequalities eKGackMNt; mechanism EdlRtwmRtUveday linear programming technique eday

pÞal;. eKGaceRbI plastic design FmμtasMrab;KNnaeRKOgbgÁúMPaKeRcIn b:uEnþCaTUeTA mechanism
method EdlbgðajenAkñúg]bsm<½n§enHKWRKb;RKan;ehIy.




                                          472                                     Appendix A

Appendix a plastic analysis and design

  • 1.
    T.Chhay Appendix A. karKNna nigkarviPaKedaylkçN³)aøsÞic Plastic Analysis and Design A >1> esckþIepþIm Introduction eyIg)anENnaMBIKMniténkar)ak;eday)aøsÞic (plastic collapse) enAkñúgEpñk 5>2/ “ kugRtaMg Bt; nigm:Um:g)aøsÞic” . kar)ak;rbs;eRKOgbgÁúMnwgekIteLIgenAeBlbnÞúkbegáItsnøak;)aøsÞicRKb;RKan;edIm,I ; begáItCa mechanism EdlnwgeFVIeGaymanPaBdabedayminmankarekIneLIgbnÞúk. enAkñúgFñwmEdl kMNt;edaysþaTic eKRtUvkarEtsnøak;)aøsÞicmYyEtb:ueNÑaH. dUcbgðajenAkñúgrUbTI A>1 snøak;nwgekIt manenAkEnøgNaEdlmanm:Um:g;Gtibrma ¬krNIenHKWenAkNþalElVg¦. enAeBlEdlm:Um:g;Bt;mantMél FMRKb;RKan;edIm,IeFVIeGaymuxkat;TaMgmUl yield/ enaHvaminGacTb;nwgkarekIneLIgrbs;m:Um:g;EfmeTot/ ehIysnøak;)aøsÞick¾RtUv)anbegáIteLIg. snøak;)aøsÞicenHRsedogKñanwgsnøak;FmμtaEdr EtxusRtg;fa snøak;)aøsÞicmanlT§PaBTb;nwgm:m:g;xøH EdldUcKñay:agxøaMgnwg rusty hinge. U 460 Appendix A
  • 2.
    NPIC lT§PaBm:Um:g;)aøsÞic (plastic momentcapacity) EdlsMKal;eday M p Cam:Um:g;Bt;EdlekIt manenARtg;snøak;)aøsÞic. vamantMélesμInwgm:Um:g;Tb;xagkñúgEdlekItBIkarEbgEckkugRtaMgEdlbgðaj enAkñúgrUbTI A>1 c EtmanTisedApÞúyKña. eKGackMNt;m:Um:g;)aøsÞicenAeBlEdleKsÁal; yield stress nigrUbragmuxkat; dUcbgðajenAkñúgrUbTI A>2. RbsinebIkarEbgEckkugRtaMgenAkñúglkçxNÐ)aøsÞiceBj RtUv)anCMnYsedaykMlaMgsmmUlsþaTicBIrEdlmantMéldUcKña nigTisedApÞúyKña enaHvanwgbegáIt couple. GaMgtg;sIueténkMlaMgnImYy²esμInwgplKuNrvag yield stress nigBak;kNþalRkLaépÞmuxkat;srub. m:Um:g;EdlbegáIteday couple xagkñúgenHKW A M p = Fy a = Fy Z x 2 Edl A CaRkLaépÞmuxkat;srub/ a CacMgayrvagTIRbCMuTMgn;énRkLaépÞBak;kNþalBIr nig Z x Cam:U Dulmuxkat;)aøsÞic. emKuNsuvtßiPaBcenøaHsßanPaB yielding dMbUg nigsßanPaB)aøsÞiceBjRtUv)ansM EdgenAkñúgm:UDulmuxkat;. BIrUbTI A>1 b eKGacsresrm:Um:g;EdlbegáIt yield dMbUg M p Fy Z x Z x M y = Fy S x nig = = M y F S y x xS pleFobenHCatMélefrsMrab;rUbragmuxkat;EdlsÁal; nigRtUv)aneKehAfa emKuNrUbrag. sMrab;Fñwm EdlKNnaeday allowable stress theory vaCargVas;én reserve capacity ehIymantMélmFüm 1.12 sMrab; W-shapes. enAkñúgFñwm b¤eRKagsþaTicminkMNt; eKRtUvkarsnøak;)aøsÞiceRcInCagmYyedIm,IbegáIt collapse mechanism. snøak;TaMgenHnwgRtUv)anbegáIttamlMdab;lMeday eTaHbICaeKmincaM)ac;dwgBIlMdab;k¾eday. eKnwgBicarNakarviPaKrcnasm<n§½sþaTicminkMNt;eRkayBIkarBiPakSatMrUvkarrbs; Specification. 461 Appendix A
  • 3.
    T.Chhay A>2> AISC Requirements AISC Specification GnuBaØatieGayeRbI plastic analysis and design enAeBl eRKOg bgÁúMenArkSaPaBlMnwgTaMg local nigTaMgmUl Rtg;cMnuc plastic collapse. edaysareKtMrUveGayFñwm b¤eRKagrgnUvPaBdabFMenAeBlEdlsnøak;)aøsÞicRtUv)anbegáIt eKRtUvkar lateral bracing CaBiess. edIm,IkarBar local buckling, AISC B5.2 TamTarfaGgát;man compact cross-sectional shape Edl λ ≤ λ p sMrab;TaMgRTnug nigsøab. sMrab;Ggát; I-shaped shape dUcCa W nig S-shapes pleFobTTwgelIkMras;EdlkMNt;BI Table B5.2 KW bf 65 bf 170 ≤ (US) ≤ (IS) 2t f Fy 2t f Fy nig h tw ≤ 640 Fy (US) h 1680 tw ≤ Fy (IS) edIm,IkarBar lateral buckling, AISC F1.2d kMNt; unbraced length Gtibrma Lb Rtg; TItaMgsnøak;)aøsÞicCa L pd EdlsMrab; I-shaped member 3600 + 2200(M 1 / M 2 ) L pd = ry (US) (AISC Equation F1-17) Fy 24820 + 15170(M 1 / M 2 ) L pd = ry (IS) Fy enAkñúgsmIkarenH M 1 Cam:Um:g;EdltUcCagenARtg;cugén unbraced length nig M 2 CamU:m:g;EdlFMCag. pleFob M 1 / M 2 KwviC¢manenAeBlEdl M 1 nig M 2 Bt;Ggát;eGaymankMeNagDub nigmantMél GviC¢manenAeBlEdlvabegáItkMeNageTal. sMrab; compact shape Edlman lateral bracing RKb;RKan; eKGacyk M n esμInwg M p sMrab; eRbIenAkñúg plastic analysis. b:uEnþ AISC F1.2d kMNt;faenAkñúgtMbn;EdlekItmansnøak;)aøsÞiccug eRkay nigenAkñúgtMbn;EdlminEk,rsnøak;)aøsÞic eKRtUveRbIviFIFmμtaedIm,IkMNt; M n . AISC Specification provision epSgeTotEdlTak;Tgnwg plastic analysis and design mandUcxageRkam. A5.1 Plastic analysis RtUv)anGnuBaØatsMrab;Et Fy ≤ 65ksi . C2.2 kMlaMgtamG½kSEdlbegáItedaybnÞúkTMnajemKuN nigbnÞúktamTisedkemKuNminRtUvFM Cag 0.75φc Ag Fy . 462 Appendix A
  • 4.
    NPIC E1.2 sMrab;ssr slenderness parameter λc minRtUvFMCag 1.5K Edl K CaemKuNRbEvg RbsiT§PaB. A >3> karviPaK Analysis RbsinebIvaGacman collapse mechanism eRcInCamYy dUcCaFñwmCab;EdlbgðajenAkñúgrUbTI A>3 eKGacrk)annUv collapse mechanism EdlRtwmRtUv ehIyviPaKCamYynwgCMnYyénRTwsþIeKalcMnYnbIrbs; plaxtic analysis EdleGayenATIenHedayKμankarRsaybBa¢ak;. !> Lower-bound theorem (static theorem): RbsinebIeKGacrk)annUvkarEbgEck m:Um:g;d¾mansuvtßiPaB ¬Edlm:Um:g;mYytUcCag b¤esμInwg M p RKb;kEnøg¦ ehIyvaGacTTYl bnÞúkedaysþaTic ¬lMnwgRtUv)anbMeBj¦ bnÞab;mkbnÞúkEdlRtUvKñaRtUvtUcCag b¤esμI collapse load. @> Upper-bound theorem (kinetic theorem): bnÞúkEdlRtUvnwg mechanism snμt;RtUvEtFM Cag b¤esμInwg collapse load. Cavi)ak RbsinebIeKGegát mechanism EdlGacmanTaMg Gs; mechanism mYyNaEdlRtUvkarbnÞúktUcCageKCa mechanism EdlRtwmRtUv. #> Uniqueness theorem: RbsineKmankarEbgEckm:Um:g;EdlGacTTYlyk)anedaysþaTic nigmansuvtßiPaB EdlenAkñúgenaH snøak;)aøsÞicRKb;RKan;begáIt collapse mechanism enaH 463 Appendix A
  • 5.
    T.Chhay bnÞúkEdlRtUvKñaCa collapse load EdlRbsinebI mechanism bMeBjTaMg upper-boud theorem nig lower-bound theorem vaCa mechanism EdlRtwmRtUv. karviPaKEdlQrelI lower-bound theorem RtUv)aneKehAfa equilibrium method ehIyRtUv)an bgðajenAkñúg]TahrN_ A>1. ]TahrN_ A>1³ rkbnÞúkcugeRkay (ultimate load) sMrab;FñwmEdlbgðajenAkñúgrUbTI A>4a eday equilibrium method rbs; plastic analysis. snμt;eKeRbI continuous lateral support nig EdlRb ePT A36 . dMeNaHRsay³ Edk A36 muxkat; W 30 × 99 Ca comapact shape ehIyCamYynwg continuous lateral support, tMrUvkar lateral bracing KWRKb;RKan; dUcenHeKGacTTYlyk plastic analysis. dMNak;karénkardak;bnÞúkelIFñwm BI working load eTAdl; collapse load RtUv)anKUsbBa¢ak;enAkñúgrUbTI A>4a-d. enAeBl working load muneBl yielding ekIteLIgRKb;TIkEnøg karEbgEckm:Um:g;Bt;RtUv)anbgðajenAkñúgrUbTI A>4a CamYynwgm:Um:g;GtibrmaEdlekItmanRtg;TMrbgáb;. enAeBlEdlbnÞúkekIneLIgbnþicmþg² yielding cab;epþImekItmanRtg;TMr enAeBlEdlm:Um:g;Bt;eTAdl; M y = Fy S x . enAeBlEdlbnÞúkekIneLIgkan;EtFM vanwgekItmansnøak;)aøsÞickñúgeBldMNalKñaenA Rtg;cugnImYy² enAeBlEdl M p = Fy Z x . enARtg;kMrwténkardak;bnÞúkenH eRKOgbgÁúMenAmanesßrPaB 464 Appendix A
  • 6.
    NPIC enAeLIy FñwmRtUv)anERbkøayeTACasþaTickMNt;edaykarekItmansnøak;)aøsÞicBIr. MechanismnwgekIt anEtenAeBlEdlekItmansnøak;)aøsÞicTIbI. vaGacekItmanenAeBlEdlm:Um:g;viC¢manGtibrmamantMél M p . edayGaRs½ynwg uniqueness theorem/ bnÞúkEdlRtUvKñaCa collapse load BIeRBaHkarEbgEck m:Um:g;KWsuvtßiPaB ehIyGacTTYlyk)anedaysþaTic. enARKb;tMNak;kalénkardak;bnÞúk plbUkénéldac;xaténm:Um:g;viC¢man nigm:Um:g;GviC¢manGti- brmaKW wL2 / 8 . enAeBl collapse, plbUkenHkøayeTACa 16M p M p + M p = wu L2 b¤ 1 wu = 8 L2 eKRtUvEteRbobeFobbnÞúkemKuNCamYynwgersIusþg;emKuN dUcenHeKeRcIneRbI φb M p Cag M p enAkñúg smIkarBIxagedIm. b:uEnþedIm,IrkSanimitþsBaØaeGaymanlkçN³samBaØ eyIgeRbI M p enARKb;]TahrN_ TaMgGs;rhUtdl;CMhancugeRkayeTIbeyIgCMnYs φb M p eTAkñúgsmIkar. lT§plEdlRtwmRtUv sMrab;]TahrN_enHKW 16φb M p wu = L2 sMrab; W 30 × 99 36(312 ) M p = Fy Z x = = 936 ft − kips 12 ehIy φb M p = 0.9(936) = 842.4 ft − kips eKk¾GacTTYltMélrbs; φb M p edaypÞal;BI Load Factor Design Selection Table enAkñúg Part 4 of the Manual. 16(842.4 ) cemøIy³ w u = (30)2 = 15.0kips / ft ]TahrN_ A>2³RbsinebIFñwmenAkñúg]TahrN_ A>1 minman continuous lateral support cUrkMNt;TItaMg EdlRtUvBRgwg. dMeNaHRsay³ snøak;)aøsÞicenAxagcugekIteLIgkñúgeBldMNalKña ehIymuneBlsnøak;enAkNþalElVg ekIteLIg. dUcenHeKKYrEtRtYtBinitü unbraced length GtibrmaedayeFobeTAnwgcug ¬snøak;cugeRkay EdlekIteLIgmintMrUvkar bracing sMrab; plastic analysis eT¦. 465 Appendix A
  • 7.
    T.Chhay edayeFobnwgsnøak;enAcugxageqVg snμt;facMnucBRgwgKWenAkNþalElVg. kñúgkrNIenH M 1 = M 2 = M p dUcenHFñwmmankMeNagDub ¬m:Um:g;TaMgBIrmansBaØadUcKña¦ dUcenH M 1 / M 2 = +1 BI AISC Equation F1-17, unbraced length GtibrmaKW 3600 + 2200(M 1 / M 2 ) 3600 + 2200(1.0) L pd = ry = (2.10) = 338.3in. = 28.2 ft Fy 36 cMNaMfa FñwmenHesÞIrEtRKb;RKan;edayminRtUvkar lateral bracing. CamYynwg lateral mYyTl;enAkNþalElVg L p = 15 ft < 28.2 ft (OK) Unbraced length EdlRtUvBicarNarYmKWrYbbBa©ÚlTaMgsnøak;enAkNþalElVg. vaminmantMbn;Edlmin enACab;nwgsnøak;)aøsÞiceT dUcenHvaminRtUvkarkarKNna design strength eT. cemøIy³ eRbI lateral brace mYyenAkNþalElVg. Mechanism method KWQrelI upper-bound theoremnigRtUvakrGegátRKb; collapse mechanism EdlGacekItman. Collapse mechanism NaEdlRtUvkarbnÞúktUcCageKnwglub eyIy bnÞúkEdlRtUvKñaCa collapse laod. eKRtUvGnuvtþeKalkarN_rbs; virtual work sMrab;viPaK mechanism nImYy². Mechanism snμt;RtUvrgnUv virtual displacement RsbeTAtamclnaEdl GacekItmanrbs; mechanism ehIyeKeGaykmμnþxageRkA nigkmμnþxagkñúgesμIKña. bnÞab;mkeKGacrk TMnak;TMngrvagbnÞúk niglT§PaBTb;m:Um:g;)aøsÞic M p . bec©keTsenHRtUv)anbgðajenAkñúg]TahrN_ A>3 nig A>4. ]TahrN_ A>3³ FñwmCab;EdlRtUv)anbgðajenAkñúgrUbTI A>5 man compact cross section Edlman design strength φb M p = 1040 ft − kips . eRbI mechanism method edIm,Irk collapse load Pu . snμt; continuous lateral support. dMeNaHRsay³ eKman failure mechanism sMrab;FñwmenHBIry:ag. dUcEdlbgðajenAkñúgrUbTI A>5 vamanlkçN³RsedogKñaEdlkMNat;Ggát;nImYy²rgnUv rigid-body motion. edIm,IGegát mechanism enAkñúgElVg AB dak; vitual rotation θ Rtg; A. karvilEdlRtUvKñaenARtg;snøak;)aøsÞicRtUv)anbgðaj enAkñúgrUbTI A>5b ehIybMlas;TItamTisQrébnÞúkKW 10θ . BIeKalkarN_rbs; virtual work kmμnþxageRkA = kmμnþxagkñúg 466 Appendix A
  • 8.
    NPIC P(10θ ) = M p (2θ ) + M pθ ¬vaminmankmμnþxagkñúgenARtg; A eT eRBaHvaminmansnøak;)aøsÞic¦ collapse load KW 3M p Pu = 10 Mechanism sMrab;ElVg AB manlkçN³xusKñabnþic³ RKb;snøak;TaMgbICasnøak;)aøsÞic. Virtual work xagkñúg nig virtual work xageRkAkñúgkrNIKW 2 Pu (15θ ) = M pθ + M p (2θ ) + M pθ enaH Pu = 15 M p 2 lT§PaBTIBIrenHRtUvkarbnÞúktUcCag dUcenHvaCa mechanism EdlRtwmRtUv. Collapse load Edlnwg TTYl)anedayeRbI φb M p CMnYseGay M p cemøIy³ Pu = 2 15 φb M p = (1040) = 139kips 2 15 467 Appendix A
  • 9.
    T.Chhay ]TahrN_ A>4³ kMNt;collapse load P sMrab; rigid frame EdlbgðajenAkñúgrUbTI A>6. Ggát; u nImYy²rbs;eRKagKW W 21×147 Edlman Fy = 50ksi . snμt; lateral support Cab;. dMeNaHRsay³ W 21×147 Ca compact shape sMrab; F y = 50ksi nigman lateral support Cab; dUc enHvabMeBjlkçxNÐkñúgkareRbIR)as; plastic analysis. dUcbgðajenAkñúgrUbTI A>6 eKman failure mode cMnYnbIsMrab;eRKagenH³ Fñwm mechanism enA kñúgGgát; BC / sway mechanism nigmYyeTotCabnSMén mechanism BIrdMbUg. eyIgcab;epþImkarviPaK mechanism nImYy²edaydak; virtual rotation θ enARtg;snøak;mYy ehIysresrsmIkarCaGnuKmn_ eTAnwgmMuenH. 468 Appendix A
  • 10.
    NPIC Virtual displacement rbs;Fñwm mechanism RtUv)anbgðajenAkñúgrUbTI A>6 b. BIsmPaBén kmμnþxageRkA nigkmμnþxagkñúg ⎛5 ⎞ ⎛2 ⎞ Pu (10θ ) = M pθ + M p ⎜ θ ⎟ + M p ⎜ θ ⎟ ⎝3 ⎠ ⎝3 ⎠ EdleKeRbI M p CMnYseGay φb M p . edaHRsayrk Pu Pu = 0.3333M p RbsinebIeKminKit axial strain enAkñúgGgát; BC / sway mechanism nwgxUcRTg;RTaydUcbgðaj enAkñúgrUbTI A>6 c CamYynwgbMlas;TItamTisedkdUcKñaRtg; B nig C . Cavi)ak muMrgVilénRKb;snøak; TaMgGs;KWlkçN³RsedogKña³ Pu (15θ ) = M p (4θ ) b¤ Pu = 0.2667 M p BIrUbTI A>6d/ eKalkarN_én virtual work sMrab; combined mechanism eGay ⎛5 ⎞ ⎛2 ⎞ Pu (15θ ) + Pu (10θ ) = M pθ + M p ⎜ θ ⎟ + M p ⎜ θ + θ ⎟ + M pθ ⎝3 ⎠ ⎝3 ⎠ Pu = 0.2133M p ¬lub¦ cemøIy³ Collapse load sMrab;eRKagKW Pu = 0.2133φb M p = 0.2133(1400) = 299kips cMNaMfa vamancMnucdUcKñaxøHrvagviFIénkarviPaKTaMgBIr. eTaHbICa equilibrium method minRtUvkarBicarNaRKb; mechanism k¾eday k¾vaRtUvkareGayeyIgdwgBI mechanism enAeBlEdlkar EbgEcgm:Um:g;snμt;RsbeTAnwg mechanism mYy. viFITaMgBIrRtUvkarkarsnμt; failure mechanism b:uEnþ enAkñúg equilibrium method eKRtUvRtYtBinitükarsnμt;nImYy²sMrab;suvtßiPaB nigkarEbgEckm:Um:g;Edl GacTTYlyk)anedaysþaTic ehIyvaminRtUvkarkarGegátRKb; mechanism eT. A >4> karKNnamuxkat; Design dMeNIrkarénkarKNnaKWRsedogKñanwgkarviPaKEdr EtvaxusKñaRtg;faGBaØtiEdlRtUvrkCalT§ PaBm:Umg;)aøsÞicEdlRtUvkar M p . eKsÁal; collapse load EdlTTYl)anBIkarKuN service load nwgem KuNbnÞúk. ]TahrN_ A>4³ FñwmCab;bIElVgdUcbgðajenAkñúgrUbTI A>7 RtUvRTnUv gravity service load. bnÞúknI- mYy²pSMeLIgedaybnÞúkefr 25% nigbnÞúkGefr 75% . eKeRbI cover plate enAkñúgElVg BC nig CD 469 Appendix A
  • 11.
    T.Chhay edIm,ITTYl)an moment strengthdUcEdl)anbgðaj. snμt; continuous lateral support nigeRCIs erIsrUbragEdksMrab;RbePT A36 . dMeNaHRsay³ Collapse load EdlTTYl)anedaykarKuN service load edayemKuNbnÞúksmRsb. sMrab; service load 45kips Pu = 1.2(0.25 × 45) + 1.60(0.75 × 45) = 67.5kips sMrab; service load 75kips Pu = 1.2(0.25 × 75) + 1.60(0.75 × 75) = 85.5kips eKRtUvGegát bIEdlman mechanism mYyenAelIElVgmYy. rUbTI A>7 c-e bgðajBI mechanism mechanism nImYy²eRkayBIrgnUv virtual displacement. enAeBlEdlsnøak;)aøsÞicekIteLIgenARtg; 470 Appendix A
  • 12.
    NPIC TMrEdlGgát;nImYy²minmanersIusþg;esμIKña vanwgekIteLIgenAeBlEdlm:Um:g;Bt;esμInwglT§PaBm:Um:g;)aøsÞic rbs;Ggát;EdlexSayCag. sMrab;ElVg AB kmμnþxageRkA = kmμnþxagkñúg 67.5(5θ ) = M p (2θ + θ ) b¤ M p = 112.5 ft − kips sMrab;ElVg BC 85.5(10θ ) = M pθ + 2M p (2θ ) + M pθ 5 3 b¤ M p = 128.2 ft − kips sMrab;ElVg CD 85.5(10θ ) = M p (θ + 2θ + θ ) 5 3 b¤ M p = 128.2 ft − kips Upper-bound theorem RtUv)anbkRsaydUcxageRkam³ tMélénm:Um:g;)aøsÞicEdlRtUvKñanwg mechanism Edlsnμt;KWtUcCag b¤esμInwgm:Um:g;)aøsÞicsMrab; collapse load. dUcenH mechanism EdlTamTarlT§PaB m:Um:g;FMCageKCa mechanism EdlRtwmRtUv. Mechanism TaMgBIrcugeRkaymantMél M p dUcKña ehIy GacnwgekIteLIgkñúgeBldMNalKña. CaTUeTAersIusþg;EdlRtUvkarCa design strength EdlRtUvkar dUc enH φb M p = 128.2 ft − kips BI Load Factor Design Selection Table, rUbragEdlRsalCageKKW W 16 × 31 Edlman design strength θ b M p = 146 ft − kips sakl,g W 16 × 31 ehIyRtYtBinitükMlaMgkat; ¬eyagtamrUbTI A>8¦ sMrab;ElVg AB ∑ M B = V A (10 ) − 67.5(5) + 128.2 = 0 V A = 20.93kips VB = 20.93 − 67.5 = −46.57 kips sMrab;ElVg BC ⎛5⎞ ∑ M B = − M p + 85.5(10) + ⎜ ⎟ M p − VC (20) = 0 ⎝3⎠ 85.5(10) + (2 / 3)M p 855 + (2 / 3)(128.2) VC = = = 47.02kips 20 20 VB = 85.5 − 47.02 = 38.48kips 471 Appendix A
  • 13.
    T.Chhay sMrab;ElVg CD ∑ M C = − M p + M p + 85.5(10) − VD (20) = 0 5 5 3 3 VD = 42.75kips = VC dUcenH kMlaMgkat;TTwgGtibrma VC KW)anmkBIElVg BC b¤esμIKña 47.02kips . BItaragbnÞúkBRgayesμIemKuNenAkñúg Part 4 of the Manual, shear design strength rbs; W 16 × 31 KW φvVn = 84.9kips > 47.02kips (OK) cemøIy³ eRbI W 16 × 31 . A >5> karsnñidæan Conclusion Remark karviPaKén mechanism EdlrgbnÞúkBRgaybgðajBIPaBsμúKsμajbEnßmeTotEdlmin)anerob rab;enATIenH. bBaðaCak;EsþgenAkñúg plastic analysis or design rYmbBa©ÚlnUvkardak;bnÞúkEbbenH y:agCak;Esþg. elIsBIenH eKKYrGegátGnþrGMeBIénT§iBlrbs;kMlaMgtamG½kS nigm:Um:g;Bt;sMrab;Ggát; EdlrgTaMgkMlaMgtamG½kS nigm:Um:g;Bt; dUcenA rigid frame enAkñúg]TahrN_ A>4 . cMeBaHviFIviPaKEdlmanlkçN³TUeTAdUcCa equilibrium method manniyayy:aglMGitenAkñúg the plastic methods of structural analysis (Neal, 1977). ehIyvamanrUbmnþEdlman lkçN³sμúKsμajsMrab; mechanism method eTotpg. CamYynwgviFIenH EdleKsÁal;faCa method of inequalities eKGackMNt; mechanism EdlRtwmRtUveday linear programming technique eday pÞal;. eKGaceRbI plastic design FmμtasMrab;KNnaeRKOgbgÁúMPaKeRcIn b:uEnþCaTUeTA mechanism method EdlbgðajenAkñúg]bsm<½n§enHKWRKb;RKan;ehIy. 472 Appendix A