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BAB-9.1_GETARAN-BEBAS-UNTUK-SISTEM-MDOF (sugeng)

Mar 10, 2016

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  • kuum 0=+

  • nn tqt )()(u =

    Tnnn )( 21 =

    tBtAtq nnnnn sincos)( +=

    )sincos()( tBtAt nnnnn +=u

    kuum 0=+

    0 ]km =+ )([ 2 tqnnnn

    00=

    0m]k = nn 2[

    0m]k = 2det[ n

  • }]{[}]{[}]{[}]{[

    2

    2

    rrr

    nnn

    MKMK

    =

    =

    ( )Tnnn MK }]{[}]{[ 2 = simetrismatriksAAT ][][ =

    ][}{][}{ 2 MK TnnTn =

    ][}{][}{ 2 MK TnnTn =}]{[}]{[ 2 rrr MK =

    }{ r

    Tn}{

    0}]{[}){(}]{[}{}]{[}{}]{[}{}]{[}{

    22

    2

    2

    =

    =

    =

    rT

    nrn

    rT

    nrrT

    n

    rT

    nnrT

    n

    MMKMK

    0}]{[}{ 0}]{[}{ == rTnrTn KjugaM

  • nnn mk 2=

    22

    22212

    12

    122121

    2

    12

    2

    21

    2

    1

    22

    221

    )(0

    0

    mkkmkkk

    mm

    kkkkk

    =+

    =+

    =

    +

    2121211211 mm , 2111 ,

    2222212

    221 mm ,

    2212 ,

    21222221112

    2212221

    2121211

    211 mmmm +=+

    0))(( 22212121112221 =+ mm

  • 02221212111 =+ mm

    00 == rTnrTn m k

    }]{[}{ 1}]{[}{ IMatauMM TnTnn ===

  • 33243

    111324

    002

    1002

    hEIkkk

    kkhEI

    mmm cc =

    =

    =

    =

    = k m

    0252

    023det

    det[

    2242

    2

    2

    2

    =+

    =

    =

    kkmmmkkkmk

    n

    n

    n

    0m]k

    mk

    mk

    mk

    mk 22

    22 222211

    ====

    05.02

    2023

    21

    11

    2

    21

    112

    1

    21

    1

    =

    ==

    kkkk

    mk

    mkkkmk

    5.0 nilaidiperoleh sehingga ,1 1121 ==

    1 nilaidiperoleh sehingga ,1 1222 ==

  • =

    =

    =

    = 11

    121

    22

    122

    21

    111

    { } 011

    111312/1

    021=

    =

    k

    T k

    { } 011

    100212/1

    021=

    =

    m

    T m

    )()(u tqt nn=

    =

    =

    +=

    +=

    n

    nnnnnnn

    n

    nnnnnn

    tBtAt

    tBtAt

    1

    1

    )cossin()(

    )sincos()(

    u

    u

    )0()(

    )0()0(

    1

    1

    =

    =

    =

    =

    n

    nnn

    n

    nnn

    qt

    q

    u

    u

    n

    nn

    n

    nnnn

    n

    n

    nnnn

    qBBt

    qAA

    )0()(

    )0()0(

    1

    1

    ==

    ==

    =

    =

    u

    u

  • )0()(

    )0()0(

    1

    1

    =

    =

    =

    =

    n

    nnn

    n

    nnn

    qt

    q

    u

    u

    n

    nn

    n

    nnnn

    n

    n

    nnnn

    qBBt

    qAA

    )0()(

    )0()0(

    1

    1

    ==

    ==

    =

    =

    u

    u

    )()sin)0(cos)0(()(11

    tqtqtqtn

    nnn

    n

    nn

    n

    nnnn

    ==

    =+=

    u

    0)0(,0)0(1)0(,1)0( 2121 ==== qqdanqq

    =

    =

    =

    = 11

    121

    22

    122

    21

    111

  • )()sin)0(cos)0(()(11

    tqtqtqtn

    nnn

    n

    nn

    n

    nnnn

    ==

    =+=

    u

    0)0(,0)0(1)0(,1)0( 2121 ==== qqdanqq ttqttq 2211 cos1)(cos1)( ==

    tqtqtq nn

    nnnn

    sin)0(cos)0()( +=

    tttutu

    212

    1 cos11cos1

    2/1)()(

    +

    =

    0kuucum =++

    qu =

    0qkqcqm =++ Tn

    0=++ qkqcqm TnTnTn

    0=++ qKqCqM nnn

    02 2 =++ nnnnnn qqq

    ,nnM mTn=nnn

    Tnn MK 2== k

    nnnnTnn MC 2== c

  • =

    =

    =

    = 11

    121

    22

    122

    21

    111

    Solusi:Menentukan matriks massa, matriks kekakuan dan matriks redamansebagai berikut

    m

    =

    = 10

    020

    02

    1 mmm

    1113 k

    22

    221

    =

    += kkk

    kkk

    2226 c

    22

    221

    =

    += ccc

    ccc

  • nTnnK k=

    { }

    { }

    { }

    { }

    =

    =

    ===

    =

    ==

    =

    ==

    =

    ===

    60075.0

    611

    111311

    015.0

    111311

    011

    111315.0

    75.0150

    111315.0

    22222

    1221

    2112

    11111

    k

    kkKK

    kK

    kK

    k.kKK

    T

    T

    T

    T

    K

    k

    k

    k

    k

    C M

    =

    = 120

    05.13005.1 cm

    =

    +

    +

    00

    60075.0

    12005.1

    3005.1

    2

    1

    2

    1

    2

    1

    qq

    qq

    qq

  • 02 2 =++ nnnnnn qqq

    ++= tqqtqetq dn

    dn

    onnodnn

    tn

    nn

    sincos)(

    21 nndn =

    =

    ++=

    n

    ndn

    dn

    onnodno

    tn t

    qqtqet nn1

    sincos)

    u(

    200/km mk 2/1 =

    0)0(,0)0(0)0(,1)0( 2121 ==== qqdanqq

    =

    =121

    21

    111

  • =

    ++=

    n

    ndn

    dn

    onnodno

    tn t

    qqtqet nn1

    sincos)

    u( 21 nndn =

    +

    =

    ttetu

    tudd

    t12

    1

    11

    2

    1 sin1

    cos15.0

    )()(

    11

    200/km mk /21 =

    0)0( ,0)0( 0)0( ,0)0( 2121 ==== qqdanqq

    =

    = 11

    22

    122

  • =

    ++=

    n

    ndn

    dn

    onnodno

    tn t

    qqtqet nn1

    sincos)

    u( 21 nndn =

    +

    =

    ttetu

    tudd

    t22

    2

    22

    2

    1 sin1

    cos11

    )()(

    22

  • }}{{}{}]{[}]{[}]{[}]{[

    0}]{[}]{[}]{[

    ii

    g

    g

    AuuMuKuCuM

    uKuCuuM

    =

    =++

    =+++

    ][}}{{ }}{]{[}{ }}{]{[}{ }}{]{[}{ MuAKACAM TigiiTiiiTiiiTi =++

    Ti}{

    ][][][2][}{

    }]{[}{

    2 MKMCMRMM

    n

    n

    Tii

    iT

    ii

    =

    =

    =

    =

    i

    igiiiii

    igiiiiiiii

    MRuAAA

    RuAMAMAM

    =++

    =++

    2

    2 2

    2

    i

    igiiiii MRuAAA =++ 2 2

    giiiii uDDD =++ 2 2

    ntdispleceme pseudo === Dii

    ii SDDM

    RA

    [ ] 5.02max )}({= ii Au

  • w1 = 2943 kg, K1 = 1600 kg/cmw2 = 4414 kg, K2 = 2000 kg/cmw3 = 4414 kg, K3 = 2400 kg/cm

    Hitung :1. Frekuensi alami dan waktu getar alami dari sistem struktur di atas.2. Gambar mode shape dari masing-masing waktu getar alami yang terjadi.3. Hitung gaya gempa disetiap lantai dari sistem struktur tersebut jika berada

    di wilayah gempa 3 dengan jenis tanah lunak SNI .

    2331

    2222

    2111

    /.5,49814414kg4414

    /.5,49814414kg4414

    /.39812943kg2943

    scmkggWmW

    scmkggWmW

    scmkggWmW

    ====

    ====

    ====

    Menyusun matriks kekakuan [K]

  • [ ]( ) ( )( ) ( ) ( )

    ( ) ( )

    ( )( )

    =

    +

    +

    =

    +

    +

    =

    =

    440020000200036001600

    0160016002400200020000

    2000200016001600016001600

    0

    0

    322

    2211

    11

    333231

    232221

    131211

    KKKKKKK

    KK

    KKKKKKKKK

    K

    Menyusun matriks massa [M]

    [ ]

    =

    =

    5,40005,40003

    000000

    3

    2

    1

    mm

    mM

  • [ ] [ ]( ) { }{ } [ ] [ ]( ) 0det0

    02

    2

    =

    =

    MKMK

    n

    n

    ( )( )

    ( )( )

    ( )( )

    ( ) ( )( ){ } ( ) ( )( ){ }( ) ( )( ){ }

    ( ) 010264,11343210231102000200031600

    5,44400160016005,444005,4360031600

    05,4440020000

    20005,4360016000160031600

    det

    05,4440020000

    20005,4360016000160031600

    05,400

    05,40003

    440020000200036001600016001600

    8246

    2

    2222

    2

    2

    2

    2

    2

    2

    2

    =+

    =

    =

    =

    =

    nnn

    n

    nnnn

    n

    n

    n

    n

    n

    n

    n

    ( ) 010264,113432102311 8246 =+ nnn Misalkan 2n =

    ( ) 010264,113432102311 823 =+

    det17,092,3722T

    rad/det92,371438/detrad1438

    det23,05,2722T

    rad/det5,27757/detrad757

    det58,08,1022T

    rad/det8,10116/detrad116

    33

    31222

    33

    22

    22222

    22

    11

    11222

    11

    ===

    =====

    ===

    =====

    ===

    =====

  • Bentuk mode 1 (vektor shape) relatif displacement. { } 11 [ ] [ ]( ) { } [ ] [ ]( ) { } 00 1212 == MKMK n

    ( )( )( )

    ( )( )

    0387820000200030781600

    016001252

    0387820000200030781600016001252

    01165,4440020000

    20001165,4360016000160011631600

    05,400

    05,40003

    440020000200036001600016001600

    1312

    131211

    1211

    13

    12

    11

    13

    12

    11

    13

    12

    112

    =+

    =+

    =

    =

    =

    =

    n

    Bila harga , dan harga-harga yang lainnya dinyatakanterhadap harga , maka diperoleh:

    0,111 =11

    ( )

    ( )( ) 4036,03878

    7825,02000038787825,02000

    0387820007825,01600

    12520160011252

    13

    13

    1312

    12

    12

    ==

    =+

    =+

    =

    =

    =

    { }

    =

    =

    4036,07825,01

    13

    12

    11

    1

  • 2 3

    [ ] [ ]{ }{ } 02 = MK n

    { }

    =

    =

    9844,0419,01

    23

    22

    21

    2

    { }

    =

    =

    634,1696,11

    33

    32

    31

    3

    rad/det92,37rad/det5,27rad/det8,10det17,0Tdet23,0Tdet58,0T

    321

    321

    ===

    ===

    { } [ ]{ }

    [ ] 0984,0419,00,1

    5,40005,40003

    4036,07825,01

    021

    = MT

    { } [ ]{ }

    [ ] 0634,1696,10,1

    5,40005,40003

    984.0419,01

    032

    = MT

  • { }

    55.0det17,092,3775.0det23,05,2775.0det58,08,10

    33

    22

    11

    ===

    ===

    ===

    d

    d

    d

    ccc

    3

    2

    1

    Trad/detTrad/detTrad/det

    2

    2

    dimana

    .

    i

    dD

    i

    ii

    Diii

    dii

    clacementpseudodispS

    MRipartisipasfaktor

    SMcRA

    ==

    ==

    ==

    [ ] { }

    [ ]

    /cmkg.det91,2/cmkg.det65,2

    /cmkg.det33,85,45,4

    3403,0782,01

    23

    22

    2

    11

    =

    =

    =

    =

    =

    RR

    MR T

  • [ ] { }{ }

    [ ] kg.det/cm97,7403,0782,01

    5,40005,40003

    403,0782,01

    111

    =

    =

    = MM T

    /cmkg.det03,28/cmkg.det00,72

    3

    22

    =

    =

    MM

    ( )( )( )( )

    ( )( )

    cm036,003.287,3998155,091.2.

    cm368,075,2798175,065,2.

    cm316,097,78,1098175,033,8.

    23

    23

    333

    22

    22

    222

    21

    21

    111

    ===

    =

    ==

    ===

    McRA

    McRA

    McRA

    d

    d

    d

    cmuuu

    u

    u

    AAAu

    =

    =

    +

    +

    =

    ++=

    388.0298.0486.0

    634.1696.11

    036.09844.0419.0

    1368.0

    403.0782.01

    316.0

    )]}{()}{()}{[(

    3

    2

    1

    max

    5.0222

    max

    5.0233

    222

    211max

    kgFFF

    F

    F

    uKF

    =

    =

    =

    =

    0659.1114797.483

    061.302388.0298.0486.0

    440020000200036001600016001600

    }]{[

    3

    2

    1

    max